The common presentations of lymphoma are widespread lymphadenopathy or development of constitutional symptoms. This paper presents a case of a patient who presented with a solitary mass detected on chest X-ray and underwent FDG-PET for further evaluation of this mass. FDG-PET is a commonly utilised technique to assess solitary nodules as it not only allows characterisation of the lesion but can also detect nodal and extra-thoracic disease with greater accuracy than the standard CT. In this case, FDG-PET demonstrated abnormal activity in the lung nodule and at the gastro-oesophageal junction. Biopsies confirmed Non-Hodgkin’s Lymphoma at both sites. The value of FDG-PET in this case was the determination of previous unsuspected disease in an unusual presentation of lymphoma and as a useful tool for monitoring the therapeutic effect post chemotherapy. FDG-PET:is of clinical benefit in the assessment of the solitary pulmonary nodule;can often detect occult metastatic disease; andis a sensitive modality for monitoring therapeutic efficacy in lymphoma.A 71-year-old lady had an incidental finding of an opacity in her left lower lobe on a chest radiograph. Thoracic CT confirmed the presence of a 1.0 cm solitary pulmonary nodule but did not identify any lymphadenopathy or evidence of distant metastatic disease.The patient was referred for an F18 FDG-PET study  for inveThe patient underwent upper gastrointestinal endoscopy. Biopsy of the gastric wall during endoscopy revealed non-Hodgkin’s lymphoma (NHL). The patient proceeded to thoracotomy for investigation of her lung lesion to definitively ascertain the nature of this lesion. Pathology again confirmed lung NHL. Therefore, the patient was treated with systemic chemotherapy for lymphoma.A follow-up post therapy FDG-PET study  showed aNon-Hodgkin’s lymphoma is a known but relatively rare cause of solitary pulmonary nodules . GastroiFDG-PET is used throughout the world in the assessment of solitary pulmonary nodule. It has been shown to have high sensitivity >95%) and high specificity (>75%) in determining whether the nodule is benign or malignant based on high uptake in the lesion [% and higFDG-PET in this case also showed a total metabolic response to treatment following appropriate chemotherapy. In the authors' institution, post-therapy assessment in NHL is one of the most common indications for FDG-PET. The findings may be of prognostic significance as total metabolic response has been associated with improved long term outlook in NHL . FDG-PETThis case thus illustrates the usefulness of FDG-PETas teaching points:in the assessment of the solitary pulmonary nodulein the detection of previously occult disease andas a sensitive modality for monitoring therapeutic efficacy in lymphoma.


Arabidopsis thaliana.The carotenoids are pure isoprenoids that are essential components of the photosynthetic apparatus and are coordinately synthesized with chlorophylls in chloroplasts. However, little is known about the mechanisms that regulate carotenoid biosynthesis or the mechanisms that coordinate this synthesis with that of chlorophylls and other plastidial synthesized isoprenoid-derived compounds, including quinones, gibberellic acid and abscisic acid. Here, a comprehensive transcriptional analysis of individual carotenoid and isoprenoid-related biosynthesis pathway genes was performed in order to elucidate the role of transcriptional regulation in the coordinated synthesis of these compounds and to identify regulatory components that may mediate this process in PSY and the co-expressed genes were found to contain an enrichment in putative BR-auxin response elements and G-boxes, which bind PIFs, further supporting a role for BRs and PIFs in regulating expression of the genes. In osmotically stressed root tissue, transcription of Calvin cycle, methylerythritol 4-phosphate pathway and carotenoid biosynthesis genes is induced and uncoupled from that of chlorophyll biosynthesis genes in a manner that is consistent with the increased synthesis of carotenoid precursors for ABA biosynthesis. In all tissues examined, induction of β-carotene hydroxylase transcript levels are linked to an increased demand for ABA.A global microarray expression correlation analysis revealed that the phytoene synthase gene, which encodes the first dedicated and rate-limiting enzyme of carotenogenesis, is highly co-expressed with many photosynthesis-related genes including many isoprenoid-related biosynthesis pathway genes. Chemical and mutant analysis revealed that induction of the co-expressed genes following germination was dependent on gibberellic acid and brassinosteroids (BR) but was inhibited by abscisic acid (ABA). Mutant analyses further revealed that expression of many of the genes is suppressed in dark grown plants by Phytochrome Interacting transcription Factors (PIFs) and activated by photoactivated phytochromes, which in turn degrade PIFs and mediate a coordinated induction of the genes. The promoters of This analysis provides compelling evidence to suggest that coordinated transcriptional regulation of isoprenoid-related biosynthesis pathway genes plays a major role in coordinating the synthesis of functionally related chloroplast localized isoprenoid-derived compounds. Comprehensive expression profiling of chloroplastic isoprenoid-related biosynthesis pathway genes was performed over a range of developmental and stress-related conditions in order to identify important regulatory components such as phytohormones and transcriptional regulatory factors that are important in coordinating their collective expression.The carotenoids are pure isoprenoids that are synthesized in chloroplasts from geranylgeranyl diphosphate (GGPP) which additionally serves as an immediate precursor for other chloroplastic localized isoprenoid biosynthesis pathways including plastoquinone (PQ), the phytol tail of chlorophylls, phylloquinones (PhQ) and tocopherols as well as the phytohormone gibberellic acid (GA). While the biochemistry of carotenoid biosynthesis (CrtBS) has been extensively studied and most genes encoding enzymes that function in the CrtBS pathway have been identified, little is known about how the synthesis of these enzymes is coordinated and additionally how this synthesis is coordinated with that of other interdependent and interrelated isoprenoid-derived compounds. We have performed a global A number of chloroplast localized isoprenoid-derived compounds constitute important components of the photosynthetic apparatus. The carotenoids perform a range of functions including the acquisition of light energy and photoprotection  and addiThe synthesis of GGPP in plastids starts from pyruvate and glyceraldehyde 3-phosphate (GAP), that can be generated directly from the Calvin cycle (photosynthesis) or glycolysis , and serPSY gene encodes the first dedicated enzyme of the CrtBS pathway which catalyzes the condensation of two molecules GGPP to form 15-cis-phytoene  [The  (NCEDs) ,13  ,15; a laPSY and select MEP pathway genes [PSY has been shown to be elevated in response to a broad spectrum of continuous (c) light wavelengths including far-red (cFR), red (cR), blue (cB) and white (cW) [PSY transcript levels have been reported to increase in response to cFR [Light activates the differentiation of etioplasts into chloroplasts in a process that is accompanied by a large and coordinated increase in the biosynthesis and accumulation of carotenoids, chlorophylls and pigment-binding proteins; this accumulation supports the development of a functional photosynthetic apparatus ,15,18. Tay genes  as well ite (cW) ,21. While to cFR . These sPSY expression has been shown to be mediated by the phytochrome (PHYs) photoreceptors. Mutant studies have shown that the induction of PSY expression in response to cFR is dependent on the light-labile PHY-A while the cR-induction is thought to be mediated by light-stable PHYs other than PHY-B [PSY and other carotenoid and chlorophyll biosynthesis genes during light-induced de-etiolation [The light-induced increase in an PHY-B . Upon lian PHY-B . Recentliolation . The PHYTranscriptional co-regulation has been shown to play a major role in coordinating cellular responses that involve multiple genes and their products. A number of studies have shown that genes that have been confirmed to be co-expressed in response to a range of conditions have correlated functional relationships, including physical interactions between their encoded proteins -28. ThesArabidopsis thaliana is ideal for studying global transcriptional responses since there are thousands of publicly available full-genome microarray experiments that encompass a broad range of experimental conditions including different developmental stages, stress, chemical and hormone treatments and mutants. In addition, analysis tools are available to identify modules of co-expressing genes and genome sequence data allows analysis of promoter regulatory regions and the identification of putative regulatory elements.The model plant species It is pertinent to acknowledge that changes in gene transcription do not necessarily translate to changes in protein abundance and functional activity due to post-transcriptional regulatory mechanisms. However, as these mechanisms rely on a gene being transcribed in the first instance, gene transcription can be considered the primary level of regulation of protein synthesis. While cells can alter the activity of specific proteins/enzymes to fine tune cellular responses, the protein must be synthesized and present at appropriate quantities for this to occur. Changes in gene transcription in response to specific stimuli can be considered a primary regulatory response that reflects a change in requirement for a specific protein(s) at a specific point in time. In addition, in comparison to a single gene, when the expression of a large group of functionally related genes is altered in a uniform manner in response to a specific stimulus, it is a stronger indicator that the transcriptional response is representative of a cell's intent to change the associated functional activity in response to the stimuli.PSY is highly co-expressed with many photosynthesis-related genes including, those involved in chlorophyll, PQ and PhQ biosynthesis as well as genes that function in the upstream Calvin cycle and MEP pathway that synthesize the commonly required GGPP precursor. Stimulus-specific transcription profiling revealed that expression of the isoprenoid biosynthesis genes is almost universally activated following germination, during both etiolated and de-etiolated growth and the induction during early development is positively regulated by BRs and GA and inhibited by ABA. During etiolated growth, the PIFs appear to suppress the expression of the genes while PHYs mediate their photoactivation. An enrichment in putative BR-auxin response elements and G-boxes (which bind PIFs) in the promoter of PSY and the co-expressed genes further supports a role for BRs and PIFs in regulating expression of the genes. In osmotically stressed root tissue, transcription of CrtBS-related genes is induced in a manner that is consistent with the increased synthesis of carotenoid precursors for ABA biosynthesis. In all tissues examined, induction of β-carotene hydroxylase transcript levels is linked to increased demand for ABA. We therefore conclude that transcriptional regulation plays a major role in coordinating the synthesis of functionally related isoprenoid-derived compounds in chloroplasts.Here we aim to elucidate the role transcriptional regulation plays in coordinating CrtBS and the synthesis of other functionally related isoprenoid-derived compounds during early development and in response to osmotic stress. A global co-expression analysis revealed that PSY as the driver gene in order to determine the level of co-expression that PSY shares with all of the other genes represented on the ATH1 microarray (22 K) chip. Key to the accuracy of this analysis is that co-expression is measured over a large number of diverse experimental conditions . PSY waoduction ,14,20,32PSY was shown to be highly correlated with many genes in the genome with the top 50 expression correlated genes (PSY-ECG50) having a Pearson correlation coefficient  ranging from 0.91 to 0.84  and e-values (<1-35) supporting the biological significance of the results.The expression of PSY-ECG50 is a strong indicator that these genes may function in common biological processes. The PSY-ECG50 was therefore subjected to a functional enrichment analysis using "Fatigoplus" [The high expression correlation of the igoplus"  which idPSY-ECG50 encode enzymes that directly function in the synthesis of chloroplastic localized isoprenoids. This includes ZDS (At3G04870) and LCY-β  [ALBINO OR PALE GREEN MUTANT 1  [GLCYERALDEHYDE-3-PHOSPHATE DEHYDROGENASE B SUBUNIT (GAPDβ) gene  functions in the Calvin cycle to synthesize GAP which is a direct substrate for the MEP pathway [Specifically, a number of genes in the es ZDS AtG04870 an = 0.86) ,35 and A = 0.86)  genes th pathway .PSY is co-expressed with genes that encode proteins that have critical functional roles in the photosynthetic machinery; these proteins include enzymes that function in the biosynthesis of carotenoids, chlorophylls and components of the photosynthetic electron transport chain including PQ, PhQ, plastidial NAD(P)H dehydrogenase complex, thioredoxin, ferredoxin, plastocyanin and the cytochrome b6/f complex as well as proteins that form structural components of photosystem I and II. The high co-expression of PSY with genes that encode proteins that have important functional roles in the photosynthetic machinery, including a number of isoprenoid biosynthesis genes, illustrates that PSY is indeed highly co-expressed with functionally related genes and this gives confidence in the accuracy of the analysis.In general, PSY-correlated interrelated isoprenoid biosynthesis genes (PSY-CIIG).The expression correlation values were next extracted for all known Arabidopsis genes that encode enzymes that function in plastidial isoprenoid biosynthesis; this included Calvin cycle and MEP pathway genes as well as carotenoid, chlorophyll, PQ, PhQ, ABA, and GA biosynthesis genes  that functions in phytol side chain biosynthesis, as well as glutamyl tRNA reductase  and glutamate 1-semialdehyde aminotransferase  that function in the upstream tetrapyrrole branch of chlorophyll biosynthesis. Significantly, the GluTR and GSA2 genes encode enzymes that catalyze the biosynthesis of 5-aminolevulinic acid (ALA) which is the rate-limiting step for this pathway [PSY  displays a high level of co-expression with PSY [PSY , that encodes a functionally active and plastid localized enzyme [-35) also shows some expression correlation, however, GGR does not have GGPPS activity in vitro and its function remains unknown although it has been suggested to encode a GPPS subunit [Of the family of 12 annotated bidopsis , only GGd enzyme , display subunit .PSY, GGPPS1 is the most highly co-expressed GGPPS in Arabidopsis with a number of other genes that encode chloroplast localized enzymes that directly use GGPP as a substrate. These genes include GGR2 , data not shown) and two genes that encode solanesyl diphosphate synthase enzymes, SPS-1 , data not shown) and SPS-2 , data not shown). The GGR2 enzyme reduces GGPP to phytyl pyrophosphate [PSY is also highly co-expressed with all enzymes that function downstream in these pathways including, as mentioned ChlSyn for chlorophyll biosynthesis, C-methyltransferase for PhQ synthesis  and, as mentioned above, APG1 and PDS2 for PQ synthesis  or GA2 , which directly use plastidial GGPP pools as substrates for GA synthesis. This implies that GGPPS1 does not function in the synthesis of GGPP for GA biosynthesis and this in turn is supported by reports that state that ggpps1 mutants show no signs of GA deficiency [The scatterplot also shows that expression of carotenoid and chlorophyll biosynthesis genes is not correlated with any of the plastid localized GA biosynthesis genes, and in particular, ficiency  and thatficiency .CCD) family, only CCD1 , and to a lesser degree CCD4 , showed any degree of expression correlation with PSY  that catalyze the synthesis of xanthoxin from β,β-xanthophylls [Of the carotenoid cleavage dioxygenase gene ; the MEP pathway genes DXPS2, MCT and GGPPS1. The very low expression level of specific genes in mature (stage 10), stratified and dry seeds may translate to very low protein/enzyme levels which would be rate-limiting for the biosynthesis of their respective molecules. While the activity of enzymes may be modulated to fine-tune biosynthesis rates, if there is no enzyme present then transcription of the gene will become the rate-limiting factor.The heat maps generated from the microarray expression analysis revealed that transcription of the h Figure . In addiPSY expression in two day dark grown plants and in response to cR  and stratified seeds, when compared to PSY, which will presumably maintain relatively high enzyme levels. The activity of the PDS and ZDS enzymes however may be regulated by the abundance of the PDS2 enzyme; PDS2 functions in the biosynthesis of PQ [PDS2 closely mirrors that of PSY throughout these stages, it may be important in regulating the activities of the PDS and ZDS enzymes.The observed induction in R Figure  in the aynthesis ,18,20. Tis of PQ ,34 whichis of PQ . Since tPSY expression has been shown to be rate-determining and a major driving force for carotenoid biosynthesis [The collective moderate induction of these genes in dark grown plants and the strong induction in response to light coincide with the timing of carotenoid and chlorophyll biosynthesis during these developmental stages. As previously stated, carotenoids, the chlorophyll precursor Pchlide and the light-activated POR enzyme have been shown to accumulate in PLB of dark grown plants and carotenoid and chlorophyll biosynthesis is strongly activated in response to light . This ilynthesis ,14, the βCHY1 and -2 and ZDS/ABA1, is in stark contrast with that of PSY during seed development in that their transcript levels remain elevated or increase during seed maturation, remain high in dry seeds and sharply decline during imbibition and in dark grown seedlings. These expression profiles are strikingly similar to a number of ABA biosynthesis genes, including NCED5, -6 and -9 that function directly downstream of ZEP/ABA1. Indeed, the induction of the ABA-responsive genes EM6 and RD29B [βCHY1 and -2, and ABA1 with ABA biosynthesis genes during later stages of seed development that coincide with the accumulation of ABA indicates that βCHY1 and -2, and ABA1 may function to drive carotenoid intermediates towards β-xanthophyll and ultimately ABA biosynthesis during these stages. This is consistent with the observed reduced expression of LCY-ε in dry seeds and reports that βchy1 βchy2 double mutants have a reduced ability to synthesize ABA during drought stress [βCHY1 and -2 and ABA1 is reduced during imbibition and in dark grown plants, their expression is rapidly induced by light with βCHY1 being expressed at levels greater than two fold above that of βCHY2. The coupling of expression of these genes with other CrtBS genes in response to light may be indicative of their essential role in synthesizing β-xanthophylls which in turn are required for photoprotection.The expression profile of a number of CrtBS genes, including, nd RD29B  at lattend RD29B . The cout stress . InteresAbscisic acid, GA and BRs have been shown to have important roles in regulating germination and post-germinative development and gene expression. Abscisic acid is known to inhibit germination and the expression of photosynthesis-related genes in imbibed seeds  while GAPSY and other photosynthesis-related genes following imbibition in continuous light is negatively regulated by ABA since in the ABA deficient mutant (aba2), induction is enhanced, while in the cyp707a1, -a2 and -a3 triple mutant, which has elevated ABA levels, the induction is almost completely abolished  and whole shoot tissue (four day old) in the BREVIS RADIX (brx) loss-of-function mutant; brx has an impaired root development phenotype due to a root-specific BR deficiency [brx was rapidly restored to control levels following three hour brassinolide (BL) treatment strongly indicating that the miss-regulated expression was due to BL deficiency [brx seedlings [brx plants have been reported to resemble that of wild-type plants [brx may only be temporary in young developing seedlings. The effect may result from ABA-mediated inhibition since BRs have been shown to positively regulate germination by reducing ABA sensitivity [The BRs also appear to have a positive role in regulating the expression of the genes. The expression of the ficiency   in line with elevated GA levels that occur at this stage [The expression of s Figure . This isynthesis . Howevermination ,58. The Arabidopsis microarray chip that does not include all genes used in our analysis; it does however include PSY and a number of other genes under investigation and thus provides a reasonable representation of the biosynthesis pathways being examined [PSY, GAPDβ, GGR2, GluTR, GSA2 and ChlSyn  via a PHYA-dependent mechanism , it doespif mutants have been shown to have a constitutive photomorphogenic (cop)-like phenotype in true dark-grown seedlings [cis motifs present in the PSY promoter and mutant studies revealed that PIF1 and other members of the PIF family function to inhibit PSY expression and carotenoid and chlorophyll biosynthesis in dark-grown seedlings [The PHYs are known to activate gene expression following their light-induced translocation from the cytoplasm to the nucleus where they specifically interact with PIFs and mediate their degradation ,74. The eedlings . A receneedlings . The exppif single and double mutants including pif1, pif3 and pif4,5 (data not shown) and this is probably a reflection of their redundant functions. In the pif -1,-3,-4,-5 quadruple mutant (pifq), however, expression of the CrtBS genes and other genes involved in the synthesis of the photosynthetic apparatus reached quantitatively similar levels to that observed in 2 day cR-exposed wild-type plants  and CHL1 were identified as direct target candidates of PIF-mediated repression in the dark based on their expression being, firstly, elevated in dark grown pifq mutants compared to wild types, secondly, rapidly elevated after one hour Rc exposure (stimulates rapid PHY-induced PIF degradation ) and thirdly, sustained after germination in two days cR. In addition, 84% of genes in the PSY-ECG50 are induced >1.5 fold in dark-grown pifq mutants  [pifq mutants. In this mutant, PHYBY276H undergoes light-independent nuclear localization which may mediate degradation of PIFs and allow the induction of light-inducible genes [phyB mutant experiment indicates that cR induction of the gene sets can occur independently of PHYB, this experiment clearly shows that active and nuclear localized PHYB can induce expression of the genes in the dark.In another related mutant experiment, dark-grown le genes ,78. ThusIn summary, these results strongly support that PHYA and PHYB have important functional roles in coordinating the transcription of the interrelated isoprenoid carotenoid and chlorophyll biosynthesis genes during de-etiolation. This process most likely involves the PHY-mediated degradation of PIFs, thus enabling light-induced gene expression.PSY-CIIG in shoot and root tissue in a time course response to osmotic stress (mannitol) which induces the synthesis of ABA and can thus help resolve how expression of CrtBS genes is coordinated with that of ABA biosynthesis in these tissues. The experimental results reveal some interesting tissue specific expression response patterns  and photosynthetic tissues, under conditions that require increased ABA biosynthesis.The increase in expression of CrtBS pathway genes in root tissue is in contrast to that in the shoot where there is a general reduction in expression of carotenoid and chlorophyll biosynthesis genes from around 3-6 h which progressively decreases up to 24 h. However, there is a strong and transient induction of NCED2 and -3 were the predominant NCEDs induced in root and shoot tissue, which is in contrast to developing seeds where induction of the NCED-5, -6, and -9 genes parallels the increase in ABA production.The NCEDs have been proposed to be key regulators of ABA synthesis since their increased expression is correlated with increased endogenous ABA concentrations . NotablyβCHY2 and ABA1 are required to increase violaxanthin precursor levels for ABA biosynthesis. In contrast, in root tissue which is a major site of ABA biosynthesis, low concentrations of carotenoids may be rate-limiting for ABA biosynthesis. We therefore propose that an increase in Calvin cycle and MEP pathway genes and a more universal induction of the CrtBS genes is required in root tissue to generate violaxanthin precursors for ABA biosynthesis, a hypothesis that is supported by studies in maize [The more universal induction of carotenoid-related biosynthesis genes in osmotically stressed roots may reflect the lower concentration of carotenoid precursors that are present in this tissue. Since photosynthetic tissue contains high concentrations of epoxycarotenoids, it appears that transcription, and presumably translation of only the late CrtBS genes, in maize  and ricein maize . The absPSY-ECG50 points to the possibility that their expression is coordinately regulated. A promoter content analysis was therefore performed in an attempt to identify the presence of enriched putative regulatory elements that may be causative for their co-expression. The analysis was performed examining regions 2000 base pairs (bp) upstream of the coding region/translation start sites (TlSS) of genes since regulatory elements have previously been identified in 5 prime untranslated regions (5' UTR) of light-induced genes [PSY which is annotated in TAIR to have a 779 bp sequence upstream of the coding region that includes two 5'UTRs and an intron. A number of elements were found to be significantly enriched in the promoters of the co-expressed PSY-ECG50 and are thus considered candidate regulatory elements that may coordinate their transcription. In addition, a number of these elements correspond to known plant cis regulatory elements including, a slightly degenerate G-box  compared to CACGTG) and the auxin-responsive element , Additional File The high expression correlation values of the genes within the ed genes ,84. ThisPSY have been shown to specifically bind the PIF1 TF resulting in inhibition of PSY expression [PSY-ECG50 is consistent with the observed PHYA dependency for induction of these genes and the inhibitory effect of PIFs on their expression in dark grown plants. We noted that one of the two G-boxes identified in the PSY promoter in this analysis is positioned in the 5' UTR in close proximity to the TlSS (-21 to -16 and -919 to -914) and both differ from those identified previously [The G-box is known to be present in the promoters of many light-regulated genes -87 and ipression . Thus, teviously  which exThe enrichment of AuxREs in the promoters of the genes is consistent with the observed BR-dependency for CrtBS gene expression in young tissues. While the AuxRE was initially believed to confer auxin responsiveness to promoters ,90, morePSY-ECG50 complements the observed transcriptional regulatory roles of BRs and PIFs respectively.In summary, the GA- and BR-dependent induction of the carotenoid and chlorophyll biosynthesis genes following germination is entirely consistent with the role of these hormones in establishing etioplast development  and the The tightly coupled expression and induction of PSY and many other isoprenoid biosynthesis genes throughout key developmental stages that correspond to the timing of increased carotenoid and chlorophyll synthesis and development of the photosynthetic apparatus strongly suggests that the coordinated transcription of these biosynthesis genes is critical in regulating and coordinating the biosynthesis of the functionally related carotenoid, chlorophyll, PQ and PhQ molecules. The phytohormones GA, BR and ABA as well as the transcriptional-related PHYs and PIFs appear to have important roles in regulating and coordinating the transcription of these isoprenoid-derived compounds.http://www.arabidopsis.leeds.ac.uk/)[An expression correlation analysis was performed for PSY using the freely available Arabidopsis co-expression tool (ACT) (s.ac.uk/). This paPSY-CIIG. Both lists were filtered to include only genes that were represented by a unique probe on the microarray chip.The analysis was performed leaving the gene list limit blank resulting in the return of a global correlation analysis of all probe sets relative to PSY ranging from the most positive to the most negatively expression correlated genes . The top 50 genes that had the highest expression correlation with PSY were extracted from the list as were genes that were included in the PSY and GGR2 was inserted into the X and Y axis and all other specifically highlighted genes were inserted in the highlight option.The co-correlation analysis was performed using the 2D scatter plot tool present on the ACT website. Probe IDs for http://babelomics.bioinfo.cipf.es/functional.html) [PSY-ECG50 expression correlated genes compared to the expected frequency in the complete genome. The top 50 genes were selected for this analysis since their expression was highly correlated with PSY . All the available functional annotation options for Arabidopsis were selected which include the three GO categories of biological process (BP), cellular component (CC) and molecular function (MF) as well as KEGG pathways. The tool uses a Fisher's exact test and returns adjusted p-values (Family Wise Error Rate) to accounting for multiple testing to determine statistical significance.A gene ontology (GO) analysis was performed using the "Fatigo plus" (version 3.1) compare tool in the Babelomics suite  ,93 to dein silico global expression analysis was subsequently performed for both gene sets in response to specific stimuli and in selected mutants to identify conditions that induce differential expression of the genes  in Genevestigator [An  Figures . The expstigator . Normalihttp://affymetrix.arabidopsis.info/narrays/experimentbrowse.pl)[http://www.ebi.ac.uk/microarray-as/ae/), GEO (NCBI) (http://www.ncbi.nlm.nih.gov/geo/) [NASCArrays (rowse.pl), TAIR-ATov/geo/) .(see attached file for experiment descriptions).http://ekhidna.biocenter.helsinki.fi/poxo) [PSY-ECG50. The POCO tool was used to identify enriched elements and the POBO tool was used to verify the presence of identified elements in the PSY promoter. The identified significantly enriched motifs were filtered to ensure that they were present and enriched in the PSY promoter and were present in greater than 70% of the genes in the PSY-ECG50.A number of tools in the POXO (fi/poxo)  promoterETW and CG conceived the initial project. OT and RV performed an initial analysis on the carotenoid biosynthesis pathway genes and promoters. SM expanded the project to include additional isoprenoid biosynthesis pathway genes, generated the results presented, interpreted data and wrote the manuscript with contributions by ETW, OT and CG. All authors read and approved the final manuscript.Additional Table 1. Extended list of genes in the PSY-correlated interrelated isoprenoid biosynthesis genes and their expression correlation relative to PSY.Click here for fileAdditional Text 1. Description of experimental conditions in the microarray data-sets examined.Click here for fileAdditional Figure 1. Heatmaps illustrating the expression of the PSY-ECG50 in response to the range of experimental conditions examined.Click here for fileAdditional Table 2. Enriched motifs identified in the promoters of genes in the PSY-ECG50.Click here for file


Neck-shoulder pain conditions, e.g., chronic trapezius myalgia, have been associated with sensory disturbances such as increased sensitivity to experimentally induced pain. This study investigated pain sensitivity in terms of bilateral pressure pain thresholds over the trapezius and tibialis anterior muscles and pain responses after a unilateral hypertonic saline infusion into the right legs tibialis anterior muscle and related those parameters to intensity and area size of the clinical pain and to psychological factors .Nineteen women with chronic non-traumatic neck-shoulder pain but without simultaneous anatomically widespread clinical pain (NSP) and 30 age-matched pain-free female control subjects (CON) participated in the study.NSP had lower pressure pain thresholds over the trapezius and over the tibialis anterior muscles and experienced hypertonic saline-evoked pain in the tibialis anterior muscle to be significantly more intense and locally more widespread than CON. More intense symptoms of anxiety and depression together with a higher disability level were associated with increased pain responses to experimental pain induction and a larger area size of the clinical neck-shoulder pain at its worst.These results indicate that central mechanisms e.g., central sensitization and altered descending control, are involved in chronic neck-shoulder pain since sensory hypersensitivity was found in areas distant to the site of clinical pain. Psychological status was found to interact with the perception, intensity, duration and distribution of induced pain  together with the spreading of clinical pain. The duration and intensity of pain correlated negatively with pressure pain thresholds. Neck shoulder pain remains a major problem in work tasks with high exposure to awkward working positions, repetitive movements and movements with high precision demands. The trapezius muscle is considered particularly affected. The prevalence of chronic neck-shoulder pain appears to be higher in women than in men ,2. It caSensory hypersensitivity ) is a common feature of several chronic neck-shoulder pain conditions, particularly those with higher levels of pain intensity and disability .. At thePressure pain thresholds (PPTs) using algometry have been used extensively to map mechanical sensitivity of mainly deep tissues such as muscles. Another modality  of the pain sensitivity of muscle can be investigated using the intramuscular hypertonic saline model with the opportunity to assess both aspects of sensitization and referred pain ).Thirty age matched healthy women with no neck/shoulder pain, recruited via advertisements in daily newspapers, comprised the control group ; mean height: 168 cm (range: 159-176 cm); mean weight: 67 kg (range: 51-90 kg)). The controls were assessed using a brief version of the clinical examination. An exclusion criterion, in addition to the above mentioned, was the presence of pain in the neck-shoulder region for more than 2-3 days during the previous 12 months.All subjects gave their written informed consent and the study was approved by the Linköping University Ethics Committee (Dnr M46-07).At the first visit those who volunteered to participate were clinically examined (see above) and if they were assessed suitable for the study, the subjects were scheduled for a second visit, 1-2 weeks later, which comprised different measurements of pain sensitivity. At the time of the clinical examination  they were given a questionnaire to be completed at home and instructed to bring it back the next visit. All measurements during the second visit were performed by the same research nurse, using the same sequence of testing, starting with pressure pain thresholds, followed by hypertonic saline infusion for all subjects.2 and was covered with 2-mm-thick rubber to minimize irritation of the skin. The pressure was applied perpendicularly to the skin at a rate of 40 kPa/s. A scale on the display helped the investigator to keep the rate of the pressure increase fixed. The participants were instructed to depress a handheld switch at their first perception of pain, i.e., when the sensation of "pressure" changed to "pain or discomfort", at which point the application of pressure ceased. The registered pressure threshold measured in kilo Pascals (kPa) was then frozen on the display unit. To avoid bruising due to tissue damage a cut-off point was set at 600 kPa. The mean values of T1+T2+T3 were calculated and presented as results.Pressure pain thresholds (PPT) were measured with an electronic algometer  at three points located in the right and left trapezius muscles, respectively; T1 , T2 (middle), and T3  and at one reference point over the right and left tibialis anterior muscles of the lower leg. Two measurements were recorded at each site with approximately a 1-minute pause between the measurements. The measurements were made in a fixed order, starting with the medialpoint over the right trapezius muscle, continuing with the corresponding points on the left side, followed by the reference points over the right and left tibialis anterior muscles. The contact area of the algometer probe tip was 1 cmA test trial, on a single point over the rhomboid muscles bilaterally, was performed to familiarize the participant with the procedure. All measurements were carried out by the same research nurse. The technique has been found to have a satisfactory repeatability .Experimental muscle pain was induced by injection of 0.5 ml sterile hypertonic saline (5.8%) into the tibialis anterior muscle of the right lower leg with the subjects placed comfortably in a sitting position for the injection. The needle was inserted into the deep mid-portion of the tibialis anterior muscle. The bolus was injected during a 20 s period using a computer-controlled syringe pump . A tube  was connected from the syringe to a stainless disposable needle  inserted into the muscle. Pain intensity was rated by the patients using a 0-10 cm electronic visual analogue scale (VAS) immediately following the injection and every 5 s until pain was no longer reported. Time to pain onset, peak pain intensity, time to peak pain (the point in time when maximum pain was first reached), mean pain intensity, and area under the VAS-time graph were extracted.Participants documented the area of pain on a front and back view body template. The pain drawings were subsequently digitized and the pain areas were estimated . Pain areas that were isolated from the area of local pain caused by the saline injection were denoted as referred pain areas. Proximal pain was defined as a pain area that spread proximal to the knee joint. The total size of the pain area and the areas of referred pain were calculated.The patients with chronic neck-shoulder pain (NSP) shaded-in their painful areas on three separate body templates (front and back views); one draThe questionnaire comprised pain intensity ratings and instruments concerning various aspects of pain and psychological factors.Pain intensity regarding clinical pain in the neck and shoulder regions was rated on a 0-100 mm paper visual analogue scale (VAS) with the defined end points "no pain" and "worst possible pain". All the questions regarding pain concerned the previous 30 days.Karolinska Sleep Questionnaire (KSQ) was used to assess sleep disturbances and fatigue over the past six months [x months . KSQ comHospital Anxiety and Depression Scale (HADS) is a self-rating scale in which the severity of anxiety and depressive symptoms is rated on a 4-point scale. Seven questions are related to anxiety and seven to depression, each with a score range of 0-21. A score of 7 or less indicates a non-case, a score of 8-10 a doubtful case, and 11 or more a definite case [ite case .Anxiety Sensitivity Index (ASI) is a 16-item self-report questionnaire. Each item asks about the amount of fear the participant experiences in regard to bodily sensations commonly associated with anxiety. Participants are asked to rate each item on a 5-point Likert-like scale ranging from very little (0) to very much (4). The ratings on the 16 items are summed for a total ranging from 0 to 64 [ 0 to 64 .Pain Anxiety Symptoms Scale-20 (PASS-20) measures fear and anxiety responses specific to pain [never (0) to always (5). to pain ,57. The Pain Catastrophizing Scale (PCS), a 13-item self-report measure designed to assess catastrophic thoughts or feelings accompanying the experience of pain. Respondents are asked to reflect on past painful experiences and to indicate the degree to which each of the 13 thoughts or feelings are experienced when in pain. The questionnaire uses a 5-point scale ranging from 0  to 4  and, in this study, we used the total sum score [um score ,59.Fear-Avoidance Beliefs Questionnaire (FABQ) was used to assess fear-avoidance beliefs. The FABQ is a 16-item self-report questionnaire aimed at quantifying the beliefs of how work and physical activity affect pain and whether they should be avoided. The two subscales, fear-avoidance beliefs for work (FABQwork) and fear-avoidance beliefs for physical activity , are scored on a 7-point Likert scale (0-6) ranging from 'strongly disagree' to 'strongly agree', where higher sum scores indicate stronger fear-avoidance beliefs [ beliefs .Pain Disability Index (PDI), a 7-item self-report instrument based on a 10-point scale that assesses perception of the specific impact of pain on disability that may preclude normal or desired performance of a wide range of functions, such as family and social activities, sex, work, life-support , and activities of daily living [y living ,62.Statistical analyses were performed in SPSS version 17 (SPSS Inc.) and SIMCA -P+ version 12.0 (Umetrics Inc). Statistical significance was defined as p < .05. Differences between groups (NSP and CON) in pain sensitivity measurements and questionnaire scores were analyzed using Mann-Whitney U-tests. Spearman correlation coefficients (rho) were calculated to analyze possible relationships between PPT and hypertonic saline-evoked pain and between pain sensitivity measurements and questionnaire scores. In the Tables the median and range values are given for each variable.2 describes the goodness of fit - the fraction of sum of squares of all the variables explained by a principal component. For details concerning PCA see Eriksson et al [Principal component analysis (PCA), using SIMCA-P+, was used to investigate multivariate correlations between pain variables and psychological variables within the NSP-group. PCA can be viewed as a multivariate correlation analysis. Related methods such as factor analysis  assume a high subject-to-variables ratio is present (5-10). But such requirements are not required for the PCA included in the SIMCA-P+ package. Furthermore a cross validation technique was used to identify nontrivial principal components (PC). This method keeps part of the data out from the model development to assess the predictive power of the model and was used to test the significance of the components. Hence, this validation technique increases the stability of the results. Such validation is not implemented in other common statistical packages e.g., SPSS. Variables loading upon the same component are correlated and variables with high loadings but with different signs are negatively correlated. Variables with absolute loadings >0.20 and that had a 95% confidence interval not equal to zero were considered significant. Significant variables with high loadings (positive or negative) are more important for the component under consideration than variables with lower absolute loadings. Variables of a certain principal component with significant loadings and the same sign are positively correlated while loadings of variables with different signs denote negative correlations. The obtained principal components are per definition not correlated and are arranged in decreasing order with respect to explained variation. Ron et al . OutlierThe median intensity and total area sizes of the NSPs' clinical neck-shoulder pain are presented in Table NSP generally perceived aspects of their psychological situation, including sleeping problems, significantly worse than CON Table . The onlAll baseline PPTs over the trapezius and tibialis anterior muscles were significantly lower in NSP compared with CON Table . The difHypertonic saline-evoked pain intensity in the tibialis anterior muscle was significantly higher in NSP, both in terms of peak pain intensity, mean pain intensity, and area under VAS curve Table . However2 and 88, 161 mm2, respectively.The pain drawings related to the induced leg muscle pain revealed a significantly larger spreading of pain, both regarding total and referred pain area sizes in the NSP group Table . ProximaFor NSP self-reported duration of chronic neck-shoulder pain was negatively correlated with baseline PPTs in the right  and left  tibialis anterior muscles, but not with PPTs in the trapezius muscles.Overall mean PPTs over right and left trapezius were positively correlated with time to pain onset after hypertonic saline infusion  in the NSP group. This suggests that patients with lower thresholds for pressure pain at the site of clinical pain experience a faster onset of hypertonic saline-induced pain in the distant area .The NSP subjects' mean pain intensity after hypertonic saline infusion was negatively correlated with PPTs in the right  and left  tibialis anterior muscles. Furthermore, the maximum hypertonic saline-induced pain intensity was negatively correlated with PPTs in right tibialis anterior  in NSP. Thus, there seems to be a relationship between pressure pain sensitivity in the lower leg, i.e., an area distant from the site of clinical pain, and the intensity of hypertonic saline-induced pain in the same area.2 = .64) with four principal components (Table A PCA of NSP yielded a significant model (cumulative RThe second component (PC2) revealed a negative relationship  between chronic pain duration, clinical neck-shoulder pain intensities (VAS) and pain intensity after hypertonic saline infusion (VAS peak) on the one hand and the pain sensitivity measures; PPT tibialis right side and left side, PPT trapezius right side and time to VAS peak after hypertonic saline on the other hand. Thus, a long history of chronic pain and high neck-shoulder pain intensities were associated with low PPTs not only in the area of clinical pain but also in distant pain-free areas. This component also showed a negative relationship between size of clinical pain areas (current and worst) and clinical pain intensities.Component three (PC3) showed a negative relationship between PPT over the right trapezius and clinical pain areas (current and least) and KSQ-Aw, i.e. individuals with larger areas of clinical pain had lower PPTs over the right trapezius muscle.The fourth component (PC4) revealed positive relationships between different pain measures and different psychological variables. The clinical pain area size at its worst, area under the VAS curve, mean VAS, peak VAS and the referred pain area after hypertonic saline were all significantly correlated with HADS-D, HADS-A and PDI. Symptoms of anxiety and depression were, thus, associated with increased pain responses to experimental pain induction and a larger spreading of the neck-shoulder pain at its worst.Major results of the present study were:• Lower thresholds for pressure pain (PPT) both within the primary clinical pain region and in remote pain free areas were found in NSP.• The hypertonic saline evoked muscle pain in a remote pain free area was significantly more intense and more locally widespread in NSP than in CON.• Symptoms of anxiety and depression were associated with increased pain responses to experimental pain induction  and a larger clinical spreading of the neck-shoulder pain at its worst in NSP.• A long history of chronic pain and high neck-shoulder pain intensities were associated with low PPTs both in the region of clinical pain and in distant pain-free areas. No correlation existed between PPTs and the different psychological aspects.Previous studies of patients with neck-shoulder pain have reported lower PPTs in painful ,41,64,65The NSP group displayed signs of widespread muscle hypersensitivity to two stimuli - i.e., pressure and chemical stimulation - as evidenced by increased sensitivity to pressure and hypertonic saline induced pain in the tibialis anterior muscle - a site distant to the primary clinical pain in the neck- shoulder region. The increased sensitivity to pressure (PPT) was particularly salient in those patients with a long history of chronic pain, as seen in the correlation between chronic pain duration and PPTs in the tibialis anterior muscles , clinical pain drawing area size and certain psychological aspects (PC4 in Table According to the second component (PC2) in Table With the present study design it was not possible to determine if the sensory hypersensitivity occurred as a direct result of chronic pain or if it was a pre-existing characteristic that predisposes some individuals to develop chronic pain. In some subjects, the local pain area after hypertonic saline infusion expanded to areas where referred pain usually arises in this region. In such conditions, the referred pain area will, by definition, be included in the local pain area, resulting in underestimates of the number of subjects with referred pain.mechanical neck disorders are used with various definitions by some authors. Independent of choice it must be pointed out that categories and diagnoses within this area are not based upon pathophysiological or pathoanatomical mechanisms.In the present study we have recruited subjects with chronic neck pain without trauma. We also have related and contrasted our results to studies concerning chronic WAD. However, the question arises if chronic WAD is a separate category compared to other chronic neck pain conditions? There is no consensus in the literature as briefly reviewed by Verhagen and co-workers ; the labWe used the powerful statistical method  to investigate the complex multivariate correlation pattern between the psychophysical tests and different psychological variables. Such methods have not been applied in earlier studies investigating the relationships being in focus of this study. The applied multivariate method can handle low subject-to-variables ratios. The PCA implemented in the statistical package used in the present study  includes, in contrast to other statistical packages , a cross-validation technique in order to achieve stable and valid principal components. However, the multivariate correlation analysis should be viewed mainly as a hypothesis generating method, given the sample size, rather than as a complete model of the interactions between the included variables. To confirm our findings, more experimental research is needed.The present study suggests that central sensitization mechanisms are involved in chronic non-traumatic neck-shoulder pain without simultaneous clinical widespread pain since sensory hypersensitivity was found in areas distant to the region of clinical pain. A long history of chronic pain and high neck-shoulder pain intensities were associated with low PPTs both in the region of clinical pain and in distant pain-free areas. Both pressure pain thresholds and chemically induced pain intercorrelated with intensity and area size of the clinical pain. Only the sensitivity to chemically induced pain was associated with the psychological status of the NSP subjects.The authors declare that they have no competing interests.All authors contributed to the design of the study and interpreted data. AS made the basic statistical analyses. The multivariate analyses were made by AS after discussion with BG. AS wrote the first version of the manuscript. All authors critically revised different versions of the manuscript. All authors read and approved the final version of the manuscript.The pre-publication history for this paper can be accessed here:http://www.biomedcentral.com/1471-2474/12/230/prepub


The extent to which Alberta oil sands mining and upgrading operations have enhanced delivery of bitumen-derived contaminants via the Athabasca River and atmosphere to the Peace-Athabasca Delta (200 km to the north) is a pivotal question that has generated national and international concern. Accounts of rare health disorders in residents of Fort Chipewyan and deformed fish in downstream ecosystems provided impetus for several recent expert-panel assessments regarding the societal and environmental consequences of this multi-billion-dollar industry. Deciphering relative contributions of natural versus industrial processes on downstream supply of polycyclic aromatic compounds (PACs) has been identified as a critical knowledge gap. But, this remains a formidable scientific challenge because loading from natural processes remains unknown. And, industrial activity occurs in the same locations as the natural bitumen deposits, which potentially confounds contemporary upstream-downstream comparisons of contaminant levels.Based on analyses of lake sediment cores, we provide evidence that the Athabasca Delta has been a natural repository of PACs carried by the Athabasca River for at least the past two centuries. We detect no measureable increase in the concentration and proportion of river-transported bitumen-associated indicator PACs in sediments deposited in a flood-prone lake since onset of oil sands development. Results also reveal no evidence that industrial activity has contributed measurably to sedimentary concentration of PACs supplied by atmospheric transport.Findings suggest that natural erosion of exposed bitumen in banks of the Athabasca River and its tributaries is a major process delivering PACs to the Athabasca Delta, and the spring freshet is a key period for contaminant mobilization and transport. This baseline environmental information is essential for informed management of natural resources and human-health concerns by provincial and federal regulatory agencies and industry, and for designing effective long-term monitoring programs for the lower Athabasca River watershed. Industrial development of oil sands deposits in northern Alberta, Canada, has grown rapidly during the past few decades. Production is projected to reach >3.3 million barrels per day by 2020 Focal points of concern include the downstream community of Fort Chipewyan, the lower Athabasca River, Lake Athabasca and the Peace-Athabasca Delta PAD;  where woDiscriminating industrial contributions from natural loads is difficult, and it remains a critical scientific challenge because the Athabasca River and its tributaries traverse surface deposits of the bitumen-rich McMurray Formation in the same areas where surface mining and processing occur. As a consequence, natural sources confound attempts to attribute differences between upstream and downstream levels of contaminants to industrial activity To date, monitoring programs have been unable to establish baseline reference conditions of natural contaminant loading to the delta, a situation identified as “almost unique in monitoring for toxic compounds” by the Federal Expert Oil Sands Advisory Panel without such knowledge, concerns about contaminant delivery to the delta will inevitably increase as oil sands development expands.Unfortunately, RAMP monitoring and other scientific studies began several decades after industrial development of the oil sands, so they cannot readily identify nor distinguish any additional contaminant loading due to industry beyond what is contributed by natural processes Here, we utilize analyses of precisely-dated lake sediment cores to establish baseline, pre-development, reference conditions for PAC deposition in the PAD. This represents the only method available to directly measure PAC concentrations prior to industrial development of the oil sands, as required to characterize the role of natural riverbank erosion as a vector for downstream deposition of PACs. Indeed, it is an approach recommended by the Federal Expert Oil Sands Advisory Panel Permission for collection of the sediment samples was provided by Parks Canada Agency  Research and Collection Permit WB-2010-6893.18O values and markedly lower content of macrofossils from the submerged moss Drepanocladus compared to post-1933 sediments, suggesting stronger river influence pre-1933 Our study design capitalizes on knowledge of past hydrological conditions that we have gained from more than a decade of field-based studies in the PAD, which is essential for informed interpretation of stratigraphic records of PACs given the hydrological complexity of the delta over space and time In September 2010, four sediment cores, 27–53 cm in length, were retrieved from each of PAD 18, 23, 31 using a gravity corer 210Pb activity at contiguous 1-cm intervals. A measured mass of ∼2-4 g of dry sediment was packed into pre-weighed tubes (SARSTEDT product No. 55.524) to a uniform height of 35 mm and a TFA Silicone Septa (Supelco®) was placed overtop the sediment, followed by 1 cm3 of 2 Ton Clear Epoxy (Devcon® product No. 14310). Three weeks were allowed for 222Rn and its decay products to reach equilibrium with 226Ra (parent isotope) prior to quantifying 210Pb, 214Bi and 214Pb activity. Activities of the radioisotopes were measured in an Ortec co-axial HPGe Digital Gamma Ray Spectrometer (Ortec GWL-120-15) interfaced with Maestro 32 software (version 5.32) at the University of Waterloo’s WATER Lab. Sample count time ranged from 23–95 hours per sample, and varied so that net 210Pb counts were >10 × the standard deviation of the net counts of a well-defined machine blank to ensure precision 210Pb activities were decay-corrected to the coring date for each lake and the 210Pb activity was density-corrected as described by One sediment core per lake was selected for dating by gamma ray spectrometric determination of 210Pb activity, which was determined from activity of 214Bi and 214Pb. Results showed that supported 210Pb activity is variable over time in the sediment cores  model nt cores . To redu210Pb-dated core was transferred to the core analyzed for PACs based on alignment of OM content profiles in both cores determined by LOI analysis . Results are consistent with cores we have previously analyzed for these lakes The sediment chronology for the analysis . Slight Samples from one core from each of the study lakes were analyzed for PACs at ALS Canada Ltd. (Edmonton). Using knowledge of the water content derived from LOI analysis, an amount of wet sediment equivalent to ≥2 g dry sediment (mean = 4.6 g dry mass) was placed into amber glass jars with Teflon lid-liners that were pre-washed with acid (5% HCl) and rinsed with solvent (dichloromethane). We combined adjacent sediment intervals for the uppermost water-rich samples in cores from PAD 18 and PAD 23 to obtain sufficient sample mass. Additionally, two samples of the 2007 Athabasca Delta flood deposit were analyzed. These flood deposit samples were kept refrigerated since collection and were similarly prepared and shipped with the other sediment core samples to ALS for analysis of 52 PACs and alkylated PACs using US Environmental Protection Agency method EPA 3540/8270-GC/MS.Identification and quantification of individual PACs had good repeatability based on analyses of replicate subsamples . Where repeated measurements of a sample were available, the average value was used for data analysis and display. In a few instances, an individual PAC was below detection limit  in one replicate but slightly above the detection limit  in the other replicate for a given sediment interval . In these cases, a random number between zero and the detection limit was generated for the first replicate below the detection limit, and then averaged with the value obtained for the second replicate to avoid underweighting the PAC concentration. For situations where all measurements for a given PAC in a sediment interval were below the analytical detection limit, the PAC measurement was treated as having a concentration of zero.A one-way Analysis of Similarities (ANOSIM) test, a nonparametric and multivariate approximate analogue of analysis of variance (ANOVA) tests A one-way Similarity of Percentages SIMPER;  analysisFor PAD 31, the study lake that was flood-prone for several decades both before and after onset of oil sands development, independent-samples t-tests were performed to determine if the mean of the sum of the river-transported bitumen-associated indicator PACs, identified by use of SIMPER analysis, differed in sediments deposited during flood-prone periods pre- versus post-onset of oil sands development. Independent-samples t-tests were performed on these data when expressed as concentrations and as proportions, because Kolmogorov-Smirnov tests identified that the distributions do not differ significantly from normal (P>0.05). Non-parametric Mann-Whitney tests provided the same conclusions as the independent-samples t-tests. These tests were performed using the software SPSS version 16.0.The composition of PACs in the 2007 Athabasca Delta flood deposit  closely The average composition of PACs in sediments deposited in PAD 31 during the two periods when the lake was flood-prone (pre-1940 and post-1982) closely matches that of the 2007 Athabasca Delta flood deposit  [10], . Nor did it include lakes flooded mainly by the Peace River which traverses undeveloped surficial deposits of bitumen. Sediments from the study lakes capture PACs transported by the Athabasca River to the delta during flood stages in spring and summer, but may not record PACs dispersed during lower river stages and by the Peace River. Thus, we recommend that periodic synoptic surveys of surface sediments and water isotope tracers be conducted for a larger suite of delta lakes (40 or more; e.g.,


All three ecotypes exhibited greater numbers and cross-sectional area of phloem cells as well as higher photosynthesis rates in response to higher PFD and especially lower temperature. The Swedish ecotype exhibited the strongest response to these conditions, the Italian ecotype the weakest response, and the Col-0 ecotype exhibited an intermediate response. Among all three ecotypes, strong linear relationships were found between light- and CO2-saturated rates of photosynthetic oxygen evolution and the number and area of either sieve elements or of companion and phloem parenchyma cells in foliar minor loading veins, with the Swedish ecotype showing the highest number of cells in minor loading veins (and largest minor veins) coupled with unprecedented high rates of photosynthesis. Linear, albeit less significant, relationships were also observed between number and cross-sectional area of tracheids per minor loading vein versus light- and CO2-saturated rates of photosynthetic oxygen evolution. We suggest that sugar distribution infrastructure in the phloem is co-regulated with other features that set the upper limit for photosynthesis. The apparent genetic differences among Arabidopsis ecotypes should allow for future identification of the gene(s) involved in augmenting sugar-loading and -transporting phloem cells and maximal rates of photosynthesis.Through microscopic analysis of veins and assessment of light- and CO In such an event, the well-known feedback inhibition by accumulated products of photosynthesis, via repression of photosynthetic genes  through use of the leaf disc oxygen electrode  and temperatures, resulting in leaves with a wide range of vascular anatomical features  and phloem . A correlation between photosynthesis and xylem hydraulic conductivity  has thuslectrode  that allfeatures  and lighA. thaliana (L.) Heynhold were investigated. Two were obtained from populations growing in north-central Sweden and central Italy, i.e., from the latitudinal extremes of this species’ natural geographic range  were germinated at an air temperature of 25°C until cotyledons emerged, then transferred to an air temperature of 15°C for 1 week before transfer to an air temperature of 8°C. Only fully expanded mature leaves of non-flowering plants at a similar stage of development , 9 h photoperiod (15 h dark) of 400 or 1000 μmol photons m2-saturated rates of photosynthetic oxygen evolution at 25 or 12.5°C and leaf vein density, as well as leaf tissue embedding in Spurr resin were conducted as previously described . Phloem and xylem parameters were quantified from 7–10 vein cross-sections per plant. Comparison of mean values , correlation coefficient, and level of significance (ANOVA) were determined using JMP statistical software .Measurements of light- and COescribed . Leaf miWhen the present study was initially undertaken, it was unknown which feature(s) of leaf vasculature, if any, may be adjusted in response to the environment. An extensive and comprehensive characterization of many different aspects of phloem anatomy was thus initially conducted see . Those c2-saturated photosynthetic oxygen evolution  as well as greater cross-sectional areas of the phloem portion  of foliar minor loading veins  when grown under cool temperatures (14°C leaf temperature) at either moderate (400 μmol photons m-2 s-1) or high (1000 μmol photons m-2 s-1) PFD. In contrast to the phloem, the total cross-sectional area of the portion of minor loading veins occupied by the xylem tissue did not vary consistently among growth conditions or ecotypes over the range of growing conditions explored here .Growth under higher PFD and lower temperature resulted in greater rates of light- and CO2-saturated rates of photosynthetic oxygen evolution and phloem cell area, these two ecotypes were compared for differences in the cross-sectional area of various cell types in individual foliar minor loading veins for leaves grown under cool temperatures and moderate PFD. Figure 2A shows that total cross-sectional area of sieve elements per vein increased in proportion with the total cross-sectional area of those phloem cells  sharing a surface with sieve elements over a range of minor loading vein sizes. Furthermore, there was a high degree of segregation between data points for the Swedish ecotype  versus the Italian ecotype. Moreover, plotting of the combined cross-sectional area of all sieve elements in a minor loading vein versus the combined cross-sectional area of all water-transporting tracheids in a minor loading vein  revealed an enhanced emphasis on sugar transport in the Swedish ecotype compared to the Italian ecotype. There was, again, almost complete segregation between data points for the Swedish versus the Italian ecotype, with a consistently larger cross-sectional area of the minor loading veins consisting of sieve elements versus tracheids in the Swedish ecotype .Since the Italian and Swedish ecotypes exhibited the greatest differences in both light- and COFigure 3. The cross-sectional area of minor loading veins occupied by sieve elements was modestly, albeit significantly, greater in the Swedish ecotype compared to the Italian ecotype when both ecotypes were grown under moderate PFD at 25°C . Growth under the same moderate PFD but cooler temperature  did not result in increased sieve element area per vein in the ecotype from Italy. In contrast, in the Swedish ecotype sieve element area per vein was significantly greater under moderate PFD in plants grown at 14°C compared to 25°C, and more than twice that of the Italian ecotype when both ecotypes were grown at 14°C in moderate PFD . All three ecotypes exhibited significant additional increases in sieve element area when grown under high PFD at 14°C, with sieve element area per vein still significantly greater in the Swedish versus the Italian ecotype . Total cross-sectional area of sieve elements per minor loading vein of the Col-0 line of A. thaliana exhibited intermediate values relative to the Italian and Swedish ecotypes, with significantly greater areas under cool temperature and increased growth light .A greater responsiveness of sieve element size to a combination of cool temperature and higher PFD in the Swedish versus the Italian ecotype is illustrated in 2-saturated rate of photosynthetic oxygen evolution , including cross-sectional area of sieve elements , total number of sieve elements , cross-sectional area of companion and phloem parenchyma cells , and number of CC + PC . Figure 4 depicts significant linear relationships between the light- and CO2-saturated rate of photosynthetic oxygen evolution versus the latter phloem features in minor loading veins of all three ecotypes grown under four different conditions (two leaf temperatures and two PFDs) when photosynthesis was measured at either 25 or 12.5°C. These positive linear relationships were strongest for light- and CO2-saturated rates of photosynthetic oxygen evolution versus the number of either sieve elements  or CC + PC  per loading vein when compared to the areas of either sieve elements  or CC + PC .Multiple features of the phloem component of minor loading veins turned out to be excellent predictors of a leaf’s light- and CO2-saturated rates of photosynthetic oxygen evolution , the tracheid cells of the xylem did show some associations with photosynthesis. Light- and CO2-saturated rates of photosynthetic oxygen evolution versus tracheid number per vein  or total cross-sectional tracheid area per vein  for Italian and Swedish ecotypes also yielded linear relationships, several of which were significant, while most were not significant. In contrast to the relationships with the cells of the phloem , light- and CO2-saturated rates of photosynthetic oxygen evolution versus tracheids exhibited two separate linear relationships corresponding to the two different growth temperatures when photosynthesis was determined at either 25°C  or 12.5°C , but converged on a single linear relationship when photosynthesis was measured at the approximate respective growth temperatures . Growth under higher PFD at a given temperature consistently resulted in greater numbers and a larger total cross-sectional tracheid area per minor loading vein . Furthermore, growth at higher temperature resulted in a greater number and a larger total cross-sectional tracheid area per minor loading vein in the Italian ecotype under a given growth light regime, but not in the Swedish ecotype . It is also important to note that foliar vein density was not significantly different among all three ecotypes under any of the growth conditions .While the total cross-sectional area of the entire xylem per vein, unlike phloem area, was not significantly associated with light- and COWe previously suggested that specialized architectural features of foliar phloem in plants (symplastic loaders) that load sugars into minor veins through plasmodesmata may provide a physical limitation to sugar export preventing full acclimation of photosynthesis in mature leaves acclimated to one condition and subsequently transferred to another . Gifford2-saturated rate of photosynthetic oxygen evolution and the proportion of minor loading veins devoted to phloem, and particularly the highly significant linear relationship between number, or total cross-sectional area, of these vein’s sugar-loading cells and sugar-transporting sieve elements versus their light- and CO2-saturated rates of photosynthetic oxygen evolution , strongly suggests that the capacity for exporting sugars from the leaf is a contributing determinant of a leaf’s maximally achievable rate of photosynthesis. It should, however, be noted that these data are correlative in nature, and that causality should be addressed in future studies.The present report provides the first data linking photosynthesis to aspects of the basic phloem structure of leaves. The association reported here between a leaf’s light- and CO2-saturated rate of 108 μmol O2m-2s-1 exhibited by the leaves of the A. thaliana ecotype from Sweden grown under high PFD and cool temperatures is several times higher than the photosynthetic rate of A. thaliana Col-0 leaves grown under high PFD and warm temperatures  and exceeds light- and CO2-saturated rates of photosynthetic oxygen evolution from herbaceous species growing in full sunlight in the winter  of each set of leaves, but two separate relationships when determined at one or the other temperature. This finding suggests that the architecture of water-transporting xylem cells is adjusted specifically for the temperature and PFD under which leaves develop, presumably to provide for physical delivery of water  at a rate matching the demand of transpirational water loss to the specific environmental conditions under which plants were growing.The linear associations between a leaf’s light- and CO stomata . Increasboth rely on proteins  subject to decreased activity with decreases in temperature, light- and CO2-saturated rates of photosynthetic oxygen evolution increased linearly with the number or cross-sectional area of phloem cells among all ecotypes and growth conditions when photosynthesis was determined at a single temperature. At any given temperature, the light- and CO2-saturated photosynthesis rate of leaves that developed at lower temperature was thus greater than that of leaves that developed at warm temperature, such that the overall effect allowed leaves to maintain a similar light- and CO2-saturated photosynthesis rate at the lower growth temperature as leaves growing under the warmer growth temperature. In other words, leaves growing at low temperature upregulated photosynthesis, as well as their apparent capacity to export products of photosynthesis through more phloem cells, to maintain a rate of photosynthesis similar to that of leaves growing at warm temperature. For A. thaliana, which is an apoplastic loader (+ co-transporters and adenosine triphosphatases) to drive the loading of sugars into the phloem. Concomitantly, the greater numbers of sieve elements per vein provide a greater cross-sectional area through which sugars can be transported, which may be important to accommodate greater sugar production resulting from higher rates of photosynthesis and/or a more viscose phloem sap that could arise from decreasing temperature  showing an intermediate response, and the Italian ecotype showing the least ready response to temperature . This difference among ecotypes prepares the ground for future molecular approaches to identify the gene(s) responsible for increased augmentation of the phloem in minor loading veins and high photosynthetic rates of the Swedish versus the Italian ecotype. Furthermore, the observed differences between the Swedish and Italian ecotypes may also be relevant to the performance of the two subjected to reciprocal transplants. Both exhibited lower survival and lower reproductive fitness in comparison to the local populations when transplanted to the other’s habitat  as destinations for sugars produced by photosynthetically active source leaves results in decreased photosynthesis rates of source leaves . In addi2 gains access to the chloroplasts  of the sieve elements of a leaf’s loading veins can represent a limitation to sugar export from leaves that represses photosynthetic genes and limits photosynthesis. It is important to note that additional foliar features co-vary with photosynthetic rate, including the stomatal pores through which COroplasts , hydraulroplasts , leaf throplasts , total croplasts , and learoplasts . Nonethe2 levels . One imp species  can alsoThe authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


Previous animal study revealed that post-implantation electrical detection levels significantly declined within days. The impact of cochlear implant (CI) insertion on human auditory pathway in terms of impedance and electrically evoked compound action potential (ECAP) variation within hours after surgery remains unclear, since at this time frequency mapping can only commence weeks after implantation due to factors associated with wound conditions. The study presented our experiences with regards to initial switch-on within 24 hours, and thus the findings about the milieus inside cochlea within the first few hours after cochlear implantation in terms of impedance/ECAP fluctuations. The charts of fifty-four subjects with profound hearing impairment were studied. A minimal invasive approach was used for cochlear implantation, characterized by a small skin incision (≈2.5 cm) and soft techniques for cochleostomy. Impedance/ECAP was measured intro-operatively and within 24 hours post-operatively. Initial mapping within 24 hours post-operatively was performed in all patients without major complications. Impedance/ECAP became significantly lower measured within 24 hours post-operatively as compared with intra-operatively (p<0.001). There were no differences between pre-operative and post-operative threshold for air-conduction hearing. A significant drop of impedance/ECAP in one day after cochlear implantation was revealed for the first time in human beings. Mechanisms could be related to the restoration of neuronal sensitivity to the electrical stimulation, and/or the interaction between the matrix enveloping the electrodes and the electrical stimulation of the initial switch-on. Less wound pain/swelling and soft techniques both contributed to the success of immediate initial mapping, which implied a stable micro-environment inside the cochlea despite electrodes insertion. Our research invites further studies to correlate initial impedance/ECAP changes with long-term hearing/speech performance. Previous research revealed little fluctuation of electrically evoked compound action potential (ECAP) thresholds over a period of five to six years after cochlear implantation (CI) The difficulty in immediate initial mapping arises mainly from the poor compliance of patients caused by postoperative pain. A locally increased impedance of soft tissues due to subcutaneous edema/hematoma following the surgery furthermore hampered the communication between the receiver and electrodes of the CI apparatus. Air bubbles, blood clots, and bone dust that possibly went in the cochlea because of manipulation during operations all added to the intricacy of this procedure. Thus it is obvious that dilemmas raised here could be ascribed at least in part to the surgical procedure itself, including a generally large-scale skin wound and the “hard” technique frequently used for cochleostomy.Commencement of electrical stimulation within 24 hours after cochlear implantation has long been performed in our department on a routine basis. By means of a modification of the commonly adopted process for CI operation, initial switch-on within 24 hours was made possible. The modified method in turn could promise a better wound condition with respect to having only a tiny amount of local pain/swelling, and very little contamination of perilymph by air bubbles, blood clots and/or bone dust on electrodes insertion.In the present study, the milieus inside the cochlea within the first few hours after cochlear implantation in terms of impedance/ECAP fluctuations was disclosed for the first time by using the aforementioned minimal invasive approach for CI operation. The charts of fifty-four patients with a profound degree of hearing impairment were reviewed. Impedance and ECAP were evaluated. Effect of gender and age was also addressed.The study conformed to the Declaration of Helsinki and the guidelines of the Institutional Ethics and Research Committee of the Cheng-Hsin General Hospital. Written informed consent was obtained from each participant or their parents with a protocol approved by the Institutional Ethics and Research Committee of the Cheng Hsin General Hospital.The charts of fifty-four subjects with a profound degree of hearing impairment  were studied . No otheUnder general anesthesia, patients were put in a supine position with their heads turned 45° away from the operated side. The surgical area was well exposed. After draping and sterilization, a 2.5 cm skin incision just anterior to the hair line was made in post-auricular region. An anterior-based skin flap was elevated by entering the areolar tissue plane and dissecting all the way to the level of Henle's spine anteriorly. A posterior-based musculoperiosteal flap for housing the receiver of cochlear implant on skull was then created by entering the subperiosteal space from the incision at a distance of about 2 cm away from the posterior wall of external ear canal. The dissection was done posteriorly from the level of Henle's spine. A well was made only when needed and no sutures were necessary for the fixation, since the tension of the musculoperiosteal flap was enough to secure the implant in position. The channel for the cable, however, was made on a routine basis. To avoid possible tissue injuries, four custom-made hooks were used to expose the cortex of the mastoid bone instead of using a self-retaining instrument (e.g. mastoid retractor). A thin rectangular chip of cortex bone (about 20×10×3 mm in size) was first harvested intact from the mastoid with a chisel, and then a drill was used for mastoidectomy. The size of this chip would be decided on according to the degree of aeration in the mastoid cavity evaluated by pre-operative computed tomography (CT). Electrocautery was seldom used unless it was necessary throughout the whole procedure in order to minimize both pain and swelling caused by burn. In addition, repeated irrigation with normal saline is mandatory, since residual blood clots and/or bone dusts would lead to significant pain and swelling of the wound postoperatively. Soft techniques Impedance and ECAP were recorded intra-operatively as well as within 24 hours after the surgery, respectively. All participants underwent pure tone audiometry (PTA) with sound field exam in an acoustically-shielded room to determine the hearing threshold before (unaided) as well as after (unaided and CI-aided) the operation, using test frequencies between 250 Hz to 8000 Hz. The maximal output of the Grason-Stadler GS61audiometer  was 120 dB HL for frequencies 250 to 4000 Hz, and 110 dB HL for 8000 Hz. A value of 5 dB was added to the maximal output threshold of the testing frequency where no responses could be found above the limit Statistical analysis was performed using the software of SAS 8.1 . Differences between values of impedance/ECAP measured intra-operatively and within 24 hours post-operatively of channels number 1, 6, 11, 16, and 22 were analyzed using paired t-test. Gender and age  differences in impedance/ECAP were evaluated using t-test. The threshold for statistical significance was set at P<0.05.The hookup between the external transmitting coil and the implanted antenna coil was done in all patients without any discomfort right after the compression dressing was removed, which in turn led to a successful switch-on of cochlear implants and thus initial mapping within 24 hours post-operatively. All patients were well-accustomed to their cochlear implants after initial mapping and usually were willing to keep hooking the transmitting coil up in their daily activities. No pre-operative medication except for one dose of prophylactic antibiotics thirty minutes before the operation was prescribed for all patients. None of the postoperative complications such as hematoma, swelling, infection, or flap failure were noted . Only onImpedance and ECAP both became significantly lower measured within 24 hours post-operatively  than those measured intra-operatively . There were no gender and age differences between pre-operative and post-operative impedance and ECAP values .There were no differences between pre-operative  and post-operative  threshold for air-conduction hearing .One major and novel finding in this study was the significant drop in the level for impedance/ECAP in less than one day after cochlear implantation. Impedance/ECAP measured within 24 hours post-operatively decreased considerably as compared with those measured intra-operatively in our subjects. Our finding was thus in line with one previous study that post-implantation electrical detection levels significantly declined within days in some animals Mechanism(s) underlying the reduced values of impedance/ECAP within one day after the surgery in our subjects remained unclear. One possibility was the interaction between the matrix enveloping the electrodes and the electrical stimulation of the initial switch-on One more plausible explanation is a spontaneous recovery of micro-environment inside cochlea from that disturbed by electrodes insertion Another possibility to consider could be the involvement of reciprocal interactions, similar to those noted in patients with idiopathic sudden sensorineural hearing loss In our study, 27 out of 54 patients came from regions outside the country Click here for additional data file.Table S2Electrically evoked compound action potential (ECAP) for all participants.(DOC)Click here for additional data file.


Arabidopsis, potato, or tomato using the split ubiquitin system. This mini-review summarizes known sucrose transporter-interacting proteins and their potential function in plants. Not all of the identified interaction partners are postulated to be located at the plasma membrane, but some are predicted to be endoplasmic reticulum-residing proteins such as a protein disulfide isomerase and members of the cytochrome b5 family. Many of the SUT1-interacting proteins are secretory proteins or involved in metabolism. Identification of actin and actin-related proteins as SUT1-interacting proteins confirmed the observation that movement of SUT1-containing intracellular vesicles can be blocked by inhibition of actin polymerization using specific inhibitors. Manipulation of expression of these interacting proteins represents one possible way to modify resource allocation by post-translational regulation of sucrose transporters.Sucrose transporters are essential membrane proteins for the allocation of carbon resources in higher plants and protein–protein interactions play a crucial role in the post-translational regulation of sucrose transporters affecting affinity, transport capacity, oligomerization, localization, and trafficking. Systematic screening for protein interactors using sucrose transporters as bait proteins helped identifying several proteins binding to sucrose transporters from apple,  Arabidopsis, a robotic screening method was established based on the split ubiquitin system in yeast  are able to form homo- and heterooligomers , SlSUT2 is also detectable in intracellular structures Figure , but undSolanum tuberosum revealed redox-dependent formation of homodimers , and an unknown protein .The attempts to confirm these interactions by co-immunoprecipitation (Co-IP) using specific antibodies or commercially available monoclonal antibodies raised against tagged and over-expressed SoSUT1 protein were not successful , but larSpinacia oleracea: a plasma membrane H+-ATPase (CAA54045) and a temperature-induced lipocalin . TILs are discussed to be involved in freezing tolerance of plants and/or in membrane stability and abiotic stress responses  is an ER-localized heterotrimeric protein translocator involved in the transport of proteins into and out of the ER  and mediMany other StSUT1-interacting proteins that have been identified either by SUS or by Co-IP are metabolic enzymes or involved in signaling or both.The yeast Gal83 protein (CAB52141) is an important player under glucose limitation conferring specificity of the Snf1 complex to target proteins such as transcription factors . A correArabidopsis 14-3-3 isoforms in response to changes in the plant nutrient status helped to identify new targets involved in nitrogen and sulfur metabolism -glucose pyrophosphorylase (AGPase) is the key enzyme in starch biosynthesis and forms an allosteric heterotetramer. The activity of AGPase is regulated, e.g., by sugars and light through post-translational redox-dependent dimerization of the small subunit .Furthermore it is known from transgenic plants with reduced expression of plant SUTs that starch levels in source leaves are dramatically increased, which can be visualized macroscopically  or by elSolanum tuberosum with an assumed antimicrobial function. It belongs to the Snakin/GASA (gibberellic acid stimulated in Arabidopsis) protein family and its physiological function was recently elucidated by generation of transgenic potato plants  signaling pathways . The expThe physiological role of StSUT1–SN1 interaction in potato remains to be elucidated. A similar phenotype as in SN1-inhibited potato is observed when the expression of another SUT-interacting protein, the protein disulfide isomerase, is inhibited in transgenic potato plants by RNA interference (RNAi) silencing . In view of the fact that StSUT1 forms dimers in a redox-dependent manner  it is inMalus domestica, belonging to the SUT4 subfamily, was immunolocalized to the plasma membrane of apple phloem and parenchyma cells. A systematic SUS screen was performed using MdSUT1 and the sorbitol transporter MdSOT6 as bait proteins  activity tests in yeast have been used to quantify the strength of interaction in the presence or absence of glucose or sucrose in the medium. Increasing sucrose concentrations inhibited MdSUT1 interaction with Cyb5, whereas varying concentrations of glucose (which is not transported by MdSUT1) did not affect the strength of interaction .73 with proline abolished this increase in affinity. It was suggested that the sugar transporter–Cyb5 complex, which is strengthened under sugar starvation, promotes sugar uptake when sugar availability is limited.Deletion constructs of the SUT-interacting Cyb5 revealed that the C-terminal region containing the membrane spanning domain of Cyb5 is essential for the interaction with sugar transporters, whereas the N-terminus only plays a role in the strength of the interaction. Thus, it is likely that the C-terminal part of Cyb5 interacts with the N-terminal part of MdSUT1 and that interaction takes place within the membrane. Co-expression of the Cyb5 protein with MdSUT1 in yeast increased affinity of MdSUT1 toward the substrate sucrose. Besides inhibiting PPI substitution of leucineArabidopsis, the same authors showed that AtSUT4, but not homologous transporters in the SUT1 or SUT2 subfamily, is able to interact with five different members of the Cyb5 family. Confirmation of interaction was obtained from pull-down assays and via BiFC  causes sterol depletion of the plant PM and thereby inhibits raft formation . The sigRaft association of plant membrane proteins may also impact lateral segregation. The potassium channel AtKAT1 was localized to microdomains and a low lateral mobility was observed . CholestInterestingly, the plasma membrane lining plasmodesmata share characteristics with membrane rafts, since typical raft proteins such as glycosylphosphatidylinositol (GPI)-anchored proteins, the callose binding protein, remorin and also sphingolipids and phytosterols are enriched in the PM of plasmodesmata .Translation of StSUT mRNAs is assumed to take place in CCs and the proteins need to be targeted to the PM of neighboring SEs . IncreasA recent paper, however, investigated lateral mobility of minimal membrane proteins by fluorescence recovery after photobleaching (FRAP) and points to the important role of the cell wall in immobilizing PM proteins, whereas association to membrane microdomains is assumed to play only a minor role in lateral mobility .Raft-like membrane compartments are regarded as organizing principle allowing attribution to protein-based sub-organellar compartments within a single cell to facilitate enzymatic reactions or cellular dynamics . MoreoveLipid rafts are assumed to represent signaling platforms perhaps enabling membrane proteins to get in close contact to signaling proteins, kinases, phytohormone receptors, etc. However, the question remains whether the redox-dependent dimerization of SUT proteins and phosphorylation/dephosphorylation events are facilitated if the protein is concentrated in raft-like microdomains.Manipulation of expression of SUT-interacting proteins represents a powerful tool to impact sucrose transport activity at the post-translational level in future experiments thereby strongly affecting carbon partitioning and resource allocation within crop plants.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.