Local root abscisic acid (ABA) accumulation depends on the spatial distribution of soil moisture in potato. Implications for ABA signalling under heterogeneous soil drying are discussed. root), root water potential (Ψroot), and root water uptake (RWU), and their impact on xylem sap ABA concentration ([X-ABA]) were measured under vertical partial root-zone drying  and horizontal partial root-zone drying  of potato (Solanum tuberosum L.). When water was withheld from the dry compartment for 0–10 d, RWU and Ψroot were similarly lower in the dry compartment when soil volumetric water content dropped below 0.22cm3 cm–3 for both spatial distributions of soil moisture. However, [ABA]root increased in response to decreasing Ψroot in the dry compartment only for HPRD, resulting in much higher ABA accumulation than in VPRD. The position of the sampled roots (~4cm closer to the surface in the dry compartment of VPRD than in HPRD) might account for this difference, since older (upper) roots may accumulate less ABA in response to decreased Ψroot than younger (deeper) roots. This would explain differences in root ABA accumulation patterns under vertical and horizontal soil moisture gradients reported in the literature. In our experiment, these differences in root ABA accumulation did not influence [X-ABA], since the RWU fraction (and thus ABA export to shoots) from the dry compartment dramatically decreased simultaneously with any increase in [ABA]root. Thus, HPRD might better trigger a long-distance ABA signal than VPRD under conditions allowing simultaneous high [ABA]root and relatively high RWU fraction.Patterns of root abscisic acid (ABA) accumulation ([ABA] Root-sourced abscisic acid (ABA) is considered a long-distance chemical signal that triggers physiological responses enhancing plant water economy  in response to soil drying . When waStudies on ‘one shoot–two root’ grafted plants with only one of the root systems subjected to soil drying have shown that root xylem sap ABA concentration coming from the ‘dry’ root increased compared with the ‘wet’ root, initially increasing xylem sap ABA concentration above the graft union. Later, as water uptake from the dry side decreased, xylem sap ABA concentration ([X-ABA]) subsequently decreased  decreases  ABA accumulation is higher in roots growing in drying soil than in wet soil; (ii) differences in Ψroot are associated with differential ABA accumulation within the root system, and are lower under vertical soil moisture gradients than under lateral gradients; and (ii) root water potential and ABA accumulation gradients within the root zone change during the day, with lower heterogeneity during night-time cessation of transpiration. To assess these hypotheses, root ABA concentrations ([ABA]root) and Ψroot were measured in hydraulically isolated soil compartments at progressive degrees of soil drying when soil moisture heterogeneity was imposed laterally or vertically. The experiments used potato, since its ABA signalling has previously been investigated under lateral PRD  were sown in pots filled with a fertilized organic loam . A moisture release curve for this substrate can be found in 3 in volume), with stainless steel mesh (0.7mm aperture) at the base to assist drainage, and were designed to fit tightly in a pressure chamber of the same volume . A 1.5cm thick quartzite gravel (15–20mm) layer divided the upper from the lower half of the pot, preventing water ascent by capillarity from the lower to the upper part. Before filling, pots were cut in half lengthwise and the two halves were stuck together with duct tape to allow easy extraction of the intact soil column at harvest. Two pairs of 6mm diameter holes (2cm apart) were punched in the wall of the pot, at the midpoint of each pot compartment. Each pair of holes allowed insertion of the two rods of a soil moisture capacitance probe  to estimate root water uptake (RWU) from each soil layer. Plants were placed in a controlled environment room, providing 400–600 μmol m–2 s–1 of irradiance, 14h of photoperiod, and 24/19 °C day/night temperature. Five batches of 11 plants were sown every other day . All plants in each batch were measured within 2 d.Potato seed tubers  was measured in three mature leaflets with a porometer . Whole-plant water uptake was calculated from the initial and final pot weights. Evaporation was assessed by determining the water loss from a well-watered pot (without a plant) and ignored as negligible (<3% of the water loss of pots containing a plant). Water uptake from each compartment was calculated from soil moisture sensor readings as described by θv) in each compartment at the time of measurement was also recorded for each plant. One of the leaves in which stomatal conductance was measured was excised and leaf water potential (Ψleaf) was determined with a pressure chamber. The plant was then de-topped and the pot inserted in a pressure chamber with the stem protruding to determine Ψroot. Since sap flow rate can influence [X-ABA]  and soil moisture sensors  inserted in each pair of holes . After 1Each pot was opened and a root segment (3–6mg in root dry weight) from the interior of each column compartment was excised, briefly (<10 s) washed in tap water to remove adhering soil particles, frozen in liquid nitrogen, and stored at –18 °C for ABA determination. The elapsed time between excision and freezing did not exceed 20 s.root) and root ABA concentration ([ABA]root). [X-ABA]root was measured in sap samples, while [ABA]root was measured in the aqueous extract obtained after incubating freeze-dried root tissue samples in a shaker at 4 °C overnight. Xylem sap of S. tuberosum does not present non-specific interference in the assay .Root samples for ABA determination were freeze dried and finely ground. Deionized water was added at 1:50 weight ratio. Both sap samples and root extracts were analysed by a radioimmunoassay .S. tuberosum L. cv. ‘Horizon’) were sown in 0.25 l pots filled with the same soil used in Experiment 1. Plants were transplanted 5–7 d after emergence into 5 l pots  divided into two compartments with equal capacity by a 3–4cm layer of the same gravel type as in Experiment 1 to disrupt water capillarity between compartments. Half of the pots were divided by a vertical gravel layer . The rest of the pots were divided by a horizontal layer   . In HPRDPlants were grown for 5 weeks after emergence, before measurement under the same environmental conditions described in Experiment 1. They were watered to field capacity after transplanting until PRD was applied. For each plant, PRD was applied for a varying period of time before measurement (from 0 to 9 d) to obtain a wide range of soil moisture content on the dry side. During PRD application, plants were watered once a day. In HPRD, pots were inclined 20° and irrigation (to field capacity) was applied to the lower side of the pot to prevent water running through the layer towards the dry side. After 15min, pots were placed back in the normal position. In VPRD, the bottom half of the pot was immersed in water for 5 s as in Experiment 1.Half of the plants were measured at the end of the night period (pre-dawn measurements), and the rest between 6 and 8h after the beginning of the photoperiod (midday measurements). Two or three plants were measured per day and time of day during a 7 d period. At midday, water uptake from the two compartments was measured as described in Experiment 1.root) was measured after thermal equilibration by dew point psychrometry with a microvoltmeter . Preliminary tests determined that thermal equilibration was attained after at least 6h. Each chamber was calibrated previously with NaCl solutions of known water potential. Another root sample was excised through the opening in the wall and processed as in Experiment 1 to determine [ABA]root.At both times of the day, a 2cm root segment was excised from the edge of the pot after partially cutting the acetate window as described by leaf and leaf xylem sap ABA concentration ([X-ABA]leaf) were determined as described for Experiment 1.For midday measurements, stomatal conductance was measured in three fully expanded leaves located in the upper third of the canopy. For pre-dawn and midday measurements, Ψθv and RWU were measured at midday with the soil moisture sensors as described in Experiment 1. For both pre-dawn and midday plants, a sample of soil from each compartment was weighed, dried at 80 °C for 4 d and the soil gravimetric water content (θg) was determined. A tight linear relationship between θv and θg was observed in midday plants , which was used to convert θg into θv for all plants to allow comparison with previous studies (e.g. No differences between wet and dry sides in root dry weight were observed in any of the two PRD distributions (data not shown).No statistical differences in any of the studied variables were found between batches of plants , so all the plants were pooled in both experiments.root, revealed that altered physiological responses were only observed in plants with θv <0.22cm3 cm–3 in the dry compartment. Plants then were separated into two groups based on θv in the dry compartment: dry, θv<0.22cm3 cm–3; wet, θv>0.22cm3 cm–3. Those groups were used to assess the effect of soil moisture in the dry compartment on [ABA]root, RWU, and Ψroot by repeated-measures analysis of variance (ANOVA) with PRD side (wet or dry) as the within factor (S) and dry compartment soil moisture (D) as the between factor in Experiment 1. For Experiment 2, S was considered the within factor, and D, measurement time of the day (T), and PRD spatial distribution (P – VPRD or HPRD) were the between factors. [X-ABA], Ψleaf, and gs were assessed by ANOVA with D as the fixed factor in Experiment 1. For Experiment 2, T and P were the fixed factors. Relationships between different variables were assessed by linear regression. All statistical analyses were carried out with SPSS 20 .Visual inspection of the relationships between soil moisture and different variables, especially [ABA]θv was lower in the dry compartment, and decreased with time of water withholding in both experiments, although it was faster in the small columns of Experiment 1  for both experiments. In Experiment 2, average (whole-pot) soil moisture (mean of wet and dry sides) was never below 0.16cm3 cm–3. PRD distribution did not influence θv, as it was similarly lower in the dry side for both HPRD and VPRD.riment 1 . Averagecm3 cm–3 . Daily iroot in the dry compartment increased but only when θv was below 0.22cm3 cm–3 in both experiments .[ABA]eriments  and 4. Ieriments . In Expeθv <0.22cm3 cm–3; RWU was much higher in the wet compartment . The fraroot in Experiment 2 was significantly lower in the dry side but only when soil moisture decreased below 0.22cm3 cm–3 , but there were no differences between PRD treatments. In Experiment 1, root xylem water potential did not differ significantly with different soil moisture in the dry compartment Ψeriments . It decrgs did not change across treatments or soil moisture levels in either experiment  in Experiment 2  observed in Experiment 2 might affect [X-ABA], with potentially higher export in HPRD than in VPRD. However, no ABA differences between different soil moisture distributions were observed, as soil drying did not significantly affect [X-ABA]leaf . Increasmoisture , was notroot in the dry compartment is coincident with very low RWUF  2–4 d after applying PRD, when RWUF from the dry side exceeded 30%  management perspective, it becomes critical to determine experimental conditions that allow simultaneous root ABA accumulation and moderate water uptake from the dry side. The main difference between our study and previous studies in potato  is soil  [X-ABA] . The rearoot did not respond to decreasing Ψroot in the former (θv <0.22), while maintaining the observed [ABA]root values in each side, the predicted weighted [ABA]root average would only clearly increase in the HPRD treatment of Experiment 2 (root.Our findings suggest that VPRD is less likely to increase [X-ABA] than HPRD, as [ABA]e former . With a riment 2 , D. ThisThe relative insensitivity of ABA synthesis to soil drying in some parts of the root system  should b


Potential allelic relationships were explored when possible. Inheritance analysis in families derived from controlled hybridization of ‘Covey’ (green leaf) and ‘Forest Pansy’ (purple leaf) suggest that purple leaf color and weeping architecture are both controlled by single recessive genes, for which the symbols pl1 and wp1 are proposed, respectively. Inheritance of gold leaf was explored in families of ‘Covey’ (green leaf) × ‘Hearts of Gold’ (gold leaf). Interpretation of inheritance of gold leaf in these families was confounded by the recovery of a leaf color phenotype in the F2 family unlike either parent. However, data suggested the action of a single locus controlling gold leaf color in ‘Hearts of Gold’, and that instability of gold leaf expression may be based on transposable element activity. Segregation of gold leaf in the F2 families of ‘Texas White’ [green leaf (C. canadensis var. texensis)] × ‘JN2’ [gold leaf (The Rising Sun)] did not fit a Mendelian ratio. Analysis of progeny of ‘Silver Cloud’ and ‘Floating Clouds’ (both showing white/green leaf variegation) with non-variegated cultivars demonstrated that variegation in ‘Silver Cloud’ is controlled by a single recessive nuclear gene, while variegation in ‘Floating Clouds’ is controlled by cytoplasmic factors. The symbol var1 is proposed for the gene controlling variegation in ‘Silver Cloud’. Double flower in progeny derived from ‘Flame’ (double flower) suggested that double flower is dominant to single flower, and that ‘Flame’ is heterozygous at the double-flower locus, for which the symbol Df1 is proposed. Allelism studies showed that the gene controlling purple leaf in ‘Forest Pansy’ is allelic to the purple leaf gene in ‘Greswan’ and that the gene controlling weeping phenotype in ‘Traveller’ (C. canadensis var. texensis) is non-allelic to the weeping gene found in ‘Covey’. Allelism of the gold leaf trait in ‘Hearts of Gold’ and ‘JN2’ was investigated, but no clear conclusions regarding allelism could be made due to recovery of leaf color phenotypes unlike either parent.Inheritance of purple, gold, and variegated foliage types, weeping architecture, and double flower was explored in F Cercis canadensis L.) is a small landscape tree that exhibits considerable morphological diversity, including variation in plant architecture, plant size, and flower and leaf colors. Specific cultivars and botanical varieties found in eastern redbud possess a variety of phenotypic characteristics whose inheritance can be studied and documented through strictly controlled breeding studies.1 Determination of inheritance for these traits can help plant breeders better understand the genetic mechanisms that lead to specific phenotypes and allow greater control while manipulating these characteristics in a breeding program. Despite the relatively high number of observable characteristics, no named genes yet exist for any phenotypic variants found in eastern redbud. Furthermore, little is known about modes of inheritance for these desirable traits, or allelic relationships between similar phenotypic variants that have arisen independently in different lineages.Eastern redbud  or at different loci . Tests for allelism are valuable tools that allow plant breeders to determine if the genes responsible for certain traits are found at the same genetic locus of two or more accessions possessing similar phenotypes. By identifying particular genes as allelic, breeders can better predict how desirable traits will be expressed in future hybridizations.The objectives of this study were to investigate the modes of inheritance for purple, gold, and variegated (green and white) leaf color, weeping architecture, and double flower in C. canadensis. Two purple leaf cultivars of independent origin currently exist: ‘Forest Pansy’ and ‘Greswan’ (Burgundy Hearts). ‘Forest Pansy’ was discovered in 1947 in Tennessee and ‘Burgundy Hearts’ was discovered in the early 2000s in Oklahoma, and both were chance seedlings. Two cultivars of independent origin that show gold leaf color are ‘JN2’ (The Rising Sun) and ‘Hearts of Gold’. Both cultivars have similar but not identical phenotypes. ‘Hearts of Gold’ shows a solid gold leaf, with only slight anthocyanin expression in newly emerging leaves, whereas ‘JN2’ produces a gold leaf with orange overtones in the petiole and newly emerged leaves. As the leaves of ‘JN2’ mature they show numerous small, dark green spots scattered over the golden adaxial leaf surface , discovered in Texas in 1989. The weeping phenotypes vary slightly between cultivars. ‘Covey’ demonstrates an abrupt weeping habit, whereas the weeping habit of ‘Traveller’ is slightly more open and spreading.Two weeping cultivars of independent origin were tested for allelism: Covey (Lavender Twist), discovered in New York state in 1991, and Traveller . Isolation blocks were separated by at least 300 m to minimize the potential for cross-contamination with other families. Pollination among F1 trees was accomplished by the presence of wild pollinating insects. Crosses, families generated, and progeny numbers are shown in Unless otherwise stated, all controlled hybridizations were performed under greenhouse conditions using potted trees and utilized identical pollination techniques. Because 1, F2, BC1P1, and BC1P2 families derived from the controlled hybridization of ‘Covey’  and ‘Forest Pansy’ . ‘Covey’ has a leaf color that is typical of wild-type Cercis , RHS green group 137A), and ‘Forest Pansy’ has leaf color RHS purple group N77A. The F1 family was created by isolating a potted tree of both ‘Covey’ and ‘Forest Pansy’ within a pollination cage. A nest of bumblebees (Bombus pennsylvanicus De Geer) was placed inside the cage to accomplish cross-pollination. The BC1P1 and BC1P2 families were created by utilizing controlled hybridization techniques previously described. The F2 family was created by growing the 23 trees of the F1 family in isolation as described above. F2 seed was harvested from individual F1 trees and kept separate, and F2 progeny were later established in the field. Characterization of leaf color was conducted in early summer at a time when purple leaf color is highly expressed. Architecture (weeping vs. non-weeping) was scored on trees in their second growing season to ensure unambiguous characterization of weeping phenotypes. Preliminary studies in our program suggested that weeping growth habit and purple leaf color were each controlled by single recessive genes. Chi-square analysis was used to test for goodness of fit to an expected ratio of 3:1 for leaf color (green leaf: purple leaf) and architecture (non-weeping: weeping), and to test for goodness of fit to an expected 9:3:3:1 ratio for a di-hybrid cross involving both traits. Linkage between the purple leaf and weeping architecture was tested using contingency analysis. Since four different F2 families were utilized in this study (each derived from separate full-sib F1 trees), data from each family were tested for departure from homogeneity.Inheritance of purple leaf color and weeping architecture, and potential linkage between these traits, was investigated in F1, F2, BC1P1, and BC1P2 families derived from hybridization of ‘Covey’ (green leaf) × ‘Hearts of Gold’ (gold leaf). Families were generated as previously described. Progeny were scored for leaf color in the greenhouse shortly after germination, at the second true leaf stage. We initially hypothesized that F2 progeny would segregate into only green leaf and gold leaf categories. However, some individuals showed a leaf color phenotype unlike either parent, classified as ‘bleached’, showing cotyledons and first true leaves that were white to light yellowish-green with sparse green streaking. Hence, segregating progeny were separated into one of three categories based on leaf color . Since five different F2 families were utilized in this study (each derived from separate full-sib F1 trees), data from each family were tested for departure from homogeneity.Inheritance of the gold leaf trait was explored in F1, F2, BC1P1, and BC1P2 families derived from hybridization of ‘Texas White’  and ‘JN2’ . In all families, ratios were calculated for the segregating families and tested using the chi-square test for goodness of fit for leaf color. For F2 analysis, two approaches were undertaken. In the first case, F2 seed was harvested from approximately 100 randomly chosen F1 trees and bulked (bulked F2 family). In the second approach, about 50–75 seeds were harvested from 38 randomly selected F1 trees and kept separate for analysis. Progeny from 5 of these 38 separate F2 families failed to segregate for both gold leaf color and gold/green (mottled) leaf color. Thirteen of the F2 families produced only green and mottled leaf progeny, lacking gold leaf segregants, prompting the authors to investigate whether or not the F1 parents of the families not segregating for gold leaf were true hybrids of ‘Texas White’ and ‘JN2’. Simple sequence repeat (SSR) loci were utilized to determine the genetic identity of 12 of the F1 parents not segregating for gold leaf color. Leaf tissue was collected from both parental genotypes (‘JN2’ and ‘Texas White’) and 12 selected intra-specific hybrids and stored at −80 °C until genomic DNA isolation. Tissue was homogenized by grinding in liquid nitrogen and DNA isolated using the Qiagen Dneasy Plant DNA isolation kit . The manufacturer’s instructions were followed for DNA isolation except that 1.5% polyvinyl polypyrolidone was added to buffer AP1. Total DNA was quantified with the NanoDrop ND-1000 ultraviolet–visible Spectrophotometer , DNA quality was determined using 2% agarose gels stained with ethidium bromide and visualized in the 2000 Gel Documentation System .Inheritance of the gold leaf phenotype was further explored in FC. canadensis microsatellite loci2 that were polymorphic between ‘JN2’ and ‘Texas White’ were selected and screened against 12 putative hybrids to confirm true hybrid origin. Microsatellite amplification was completed using the following conditions: 10 μL PCR reactions contained 0.4 ng genomic DNA, 2.5 mM MgCl2, 1 × GeneAmp PCR Buffer II , 0.2 mM dNTPs, 0.25 µM primer, 0.6 U AmpliTaq Gold DNA polymerase (Applied Biosystems), and sterile, nanopure water. Cycling conditions were as follows: 1 cycle of 94 °C for 5 min, 35 cycles of 94 °C for 40 s, 55 °C for 40 s, 72 °C for 30 s, and 1 cycle of 72 °C for 4 min. PCR products were sized on the QIAxcel Capillary Electrophoresis System  using an internal 25-bp DNA step ladder.Primer pairs from 3 We utilized a conservative 2 bp allelic class size range because of the 2 bp resolution of the QIAxcel Capillary Electrophoresis System (Qiagen). All loci selected for hybrid confirmation were polymorphic and differed by at least 4 bp in the parents to eliminate potential resolution issue during allele separation. The multilocus genotypic data for each hybrid was compared to the parents for hybrid confirmation. To simplify hybrid confirmation, only loci that were homozygous in each respective parent were utilized. Thus, every hybrid should have two alleles detected for each locus analyzed.Raw allele length data for each sample and locus were binned into allelic classes using the program FLEXIBIN.1 progeny derived from controlled hybridization of ‘Dwarf Alba’ (single flower) × ‘Flame’ (double flower). The double-flowered ‘Flame’ is essentially female sterile, and rarely sets fruit. The double-flowered F1 progeny recovered from the aforementioned hybridization were also female sterile, precluding the recovery of F2 progeny. Compared to the typical five petals in a flower of redbud, ‘Flame’ typically shows 30–40 petals per flower (unpublished data). Atypically, in 2005 a tree of ‘Flame’ growing among a diverse collection of redbud cultivars set fruit. Hence, viable seed was collected and obtained from Hidden Hollow Nursery  and open-pollinated seedlings were evaluated to obtain additional evidence on inheritance of double flower.Inheritance of the double flower phenotype  was inve1 families generated from the hybridization of ‘Floating Clouds’ (variegated leaf) with non-variegated cultivars ‘Covey’ , NC2006-14, ‘Texas White,’ and ‘JN2’. Inheritance of variegated leaf was investigated further in F1 and F2 families derived from reciprocal hybridizations of ‘Silver Cloud’ (variegated leaf) and ‘Covey’. In both cases, ratios were calculated for the segregating families and tested using the chi-square test for goodness of fit. Both ‘Floating Clouds’ and ‘Silver Cloud’ have variegated green leaves with white sectors. However, both were discovered as chance seedlings of independent origin. Their phenotypes are similar, but ‘Floating Clouds’ has more prominent white sectors and leaves are more resistant to sunscald .Inheritance of the variegated leaf phenotype was investigated in five different F1 progeny to exhibit purple leaf color. Conversely, if the purple phenotype is controlled by different loci in the two cultivars, one would expect all F1 progeny to exhibit green leaf color. Progeny were scored for purple leaf color in the greenhouse, after development of two true leaves. Additionally, open-pollinated seed of ‘Greswan’ was obtained from trees growing at the JC Raulston Arboretum  and from Green Leaf Nursery,  to verify if the purple leaf phenotype exhibited by ‘Greswan’ is recessive. Because eastern redbud is self-incompatible, all open-pollinated seed originate from outcrossing. Open-pollinated seedlings should show green leaves if the purple leaf phenotype is recessive in ‘Greswan’, assuming no outcrossing to purple leaf plants.Preliminary analysis suggested that purple leaf color in ‘Forest Pansy’ is controlled by a single recessive gene. In order to determine if the genes controlling purple leaf color in ‘Forest Pansy’ and ‘Greswan’ are allelic, controlled hybridizations were accomplished under greenhouse conditions. Because both ‘Forest Pansy’ and ‘Greswan’ show a high degree of female sterility, ‘Greswan’ was utilized as the male parent, and the purple leaf cultivar ‘Ruby Falls’ , derived from ‘Forest Pansy’ was used as the female parent. If controlled by the same locus, and if both cultivars are homozygous for the recessive mutation, one would predict all F1 family. Alternatively, if the weeping genes are non-allelic, one would expect only non-weeping offspring in the F1 family. Initial scoring of progeny was performed approximately 7 months after germination, at the end of the first growing season. Subsequently, all progeny were again scored in mid-summer of the second growing season to confirm accuracy of scoring.Allelism of the genes controlling weeping phenotype in ‘Covey’ and ‘Traveller’ was investigated. Because ‘Traveller’ shows almost absolute male and female sterility, it cannot be used in controlled crosses. However, a rare open-pollinated seedling of ‘Traveller’ (designated NC2011-1) was obtained in our program in 2011. The seedling is non-weeping, but presumably heterozygous for the weeping allele. Hence, hybridization between NC2011-1 and ‘Ruby Falls’ (derived from ‘Covey’) is informative for allelism determination, and reciprocal crosses were made in the greenhouse. If the weeping phenotypes are controlled by allelic genes, one would predict recovery of 50% weeping progeny in the F1 progeny to exhibit gold leaf color. Conversely, if the gold leaf phenotype is controlled by different loci in the two cultivars, one would expect all F1 progeny to exhibit green leaf color.Both gold leaf cultivars (Hearts of Gold and JN2) were crossed in reciprocal combinations to investigate allelism of the genes controlling gold leaf color. Controlled hybridizations were made in a greenhouse, and progeny were scored for leaf color in the first growing season in both a greenhouse and field setting. If controlled by the same locus, and if both cultivars are homozygous for the recessive mutation, one would predict all F1 family of ‘Covey’ × ‘Forest Pansy’ consisted of 23 plants, all showing non-weeping growth habit and green leaves. The F2 seed was derived from random intercrossing of 23 F1 trees and collected from four separate F1 trees, providing 1586 progeny. Leaf color of F2 progeny could be easily discerned in early stages of development, typically by observing the first true leaves. Cotyledons of purple leaf plants were green, identical to the cotyledons of green leaf progeny. Segregating F2 progeny exhibiting the purple leaf phenotype was clearly discernable from those exhibiting the green phenotype in early summer, the time of scoring in the field , so data were combined prior to analysis. Segregation for leaf color fit the expected ratio of 3:1 (green leaf: purple leaf) at P = 0.02  × ‘Forest Pansy’ segregated in the expected ratio of 1:1 (green leaf: purple leaf) at P = 0.82  at P = 0.26  at P = 0.44 , which was assessed at the second true leaf stage. Cotyledon color was highly predictive of leaf color. Green leaf plants expressed a cotyledon color typical of wild type  green group 137A; The Fow spots . Typical2 of green, gold, and bleached progeny did not match any known Mendelian segregation ratio, perhaps suggesting the interaction of more than one locus. However, when all non-green segregants were combined into a single category (gold + bleached), each of the five F2 families fit a ratio of 3:1 , so data were combined prior to analysis. Combined data fit a ratio of 3:1 (green leaf: gold + bleached leaf) at P = 0.06  coupled with the presence of limited chlorophyll in the cotyledons of bleached progeny suggests that the bleached phenotype may be gold leaf segregants that experienced a TE insertion or excision event early in development, rendering them highly disabled in chlorophyll synthesis. Several instances in our study were documented in which a viable bleached segregant ultimately developed into a very light gold phenotype, reflecting the transient nature of TE-based phenotypes. TE activity could be the cause for the moderate degree of phenotypic instability witnessed in some F2 progeny derived from ‘Covey’ × ‘Hearts of Gold’ . Even when gold and bleached categories were combined into a single group (gold + bleached), this family showed a deficiency of non-green leaf progeny that resulted in a distortion of the expected 1:1 ratio (green leaf: gold + bleached leaf), at P < 0.001  × ‘JN2’ (gold leaf with green spots) consisted of 463 progeny, all of which showed green leaf color. The F1 progeny were intermated , and F2 seed was collected from about 100 F1 trees and bulked. The bulk F2 family segregated for both green, entire gold (no green spots), and mottled leaf phenotypes . Plants scored as gold leaf had cotyledons that were distinguishably lighter in color (RHS yellow-green group 144A). The mottled category possessed cotyledons that were identical to the gold cotyledon classification. The F2 and backcross plants were separated into one of three categories based on leaf phenotype , which was assessed at the second true leaf stage. Segregation in the F2 of green, gold, and mottled progeny did not match any known Mendelian segregation ratio, perhaps suggesting the interaction of more than one locus. As with the ‘Covey’ × ‘Hearts of Gold’ study, all non-green segregants were pooled into a single category (gold + mottled) and analyzed for a goodness of fit to a 3:1 ratio (green leaf: gold + mottled leaf). However, analysis of the bulk F2 family did not fit the expected ratio of 3:1 (green leaf: gold + mottled leaf) at P < 0.001, showing a highly significant underrepresentation of the gold + mottled progeny category  in 24 of the 38 families from the expected 3:1 ratio (green leaf: gold + mottled leaf), again with a deficiency in ‘gold + mottled’ progeny  failed to show any gold leaf or mottled segregants . Based on a single gene model (with gold leaf being recessive to green leaf), the likelihood of recovering only green leaf segregants from a population of 303 segregating progeny is 1.39 × 10−38. Thirteen additional F2 families  showed no gold progeny, but only green and mottled progeny.Subsequently, in order to better characterize the segregation distortion in the bulk F progeny . Gold le1P1 family (‘Texas White’ × (‘Texas White’ × ‘JN2’)) were green leaf (1P2 family (‘JN2’ × (‘Texas White’ × ‘JN2’)) segregated for both green and gold leaf, but the mottled phenotype was not recovered. Segregation in the BC1P2 family deviated significantly from the expected test ratio of 1:1 (green leaf: gold leaf) (P = 0.007), showing a deficiency of gold leaf segregants  were used to confirm hybridization between the parents ‘JN2’ and ‘Texas White’. These loci were homozygous and polymorphic between the parents. All of the putative hybrids  tested were heterozygous and had a single allele from each parent, thus confirming hybridization between ‘Texas White’ and ‘JN2’Alternatively, the distortion in segregation ratios in the bulked F1 trees proved to be true hybrids, one would predict them to be heterozygous for the gold leaf allele derived from ‘JN2’. That five of these families failed to segregate for gold or mottled leaf color, and 13 additional families (seven verified as true hybrids using SSR’s) segregated only for mottled but not gold progeny suggests that some factor is impacting transmission of the gold leaf allele. Activity of TE could be responsible for the distortion in the observed ratios and complete lack of gold leaf and mottled progeny in specific F2 families. If the gold leaf mutation is based on a TE insertion, a TE excision event during male gametogenesis could restore function and result in a modified allele that functionally behaves as a green leaf allele, resulting in F1 progeny that are homozygous for green leaf. These homozygous green F1 progeny could account for the underrepresentation of gold leaf and mottled segregants in the bulk F2 family, and lack of gold and mottled segregation in F2 families derived from individual F1’s.Since all tested F2 family may also represent TE element-based variation. A similar phenomenon may explain the bleached phenotype in the ‘Covey’ × ‘Hearts of Gold’ F2 progeny.The leaf phenotype of the ‘JN2’ parent, showing a predominantly gold leaf with numerous random islands of green of varying size, is suggestive of TE activity. The mottled leaf phenotype recovered in progeny of ‘JN2’ could be the result of a partial TE excision at the gold allele during gametogenesis or early embryo development, resulting in partial restoration of function and creation of a unique leaf color phenotype similar to ‘JN2’, and unlike the green leaf ‘Texas White’ parent. Recovery of solid gold progeny lacking green spots in F1 family.Assuming maternal inheritance of chloroplasts and mitochondria in redbud, our results confirm that the gold leaf trait in ‘JN2’ is not inherited cytoplasmically as ‘JN2’ was used as the male parent in the initial controlled hybridization that created the F1 progeny derived from the hybridization of ‘Dwarf Alba’ × ‘Flame’ were both double flowered, suggesting dominance of double flower. Analysis of F1 progeny derived from open pollination of ‘Flame’ showed segregation for single flower and double flower. Segregation for single and double flower did not fit the expected test ratio of 1:1 (single flower: double flower) at P < 0.001  showed that leaf variegation in that cultivar is inherited cytoplasmically  fit the expected test ratio of 3:1 (green leaf: variegated leaf) at P = 0.02 and P = 0.74, respectively  and ‘Ruby Falls’ (homozygous for the weeping gene derived from ‘Covey’) were all non-weeping except for a single weeping individual, recovered in the family derived from NC2011-1 as the female parent. This individual is presumably the result of a rare self-pollination event in NC2011-1. A total of 316 progeny were evaluated in the reciprocal families combined. Recovery of 50% weeping progeny would have been expected if the genes were allelic, hence these results show the genes are non-allelic. Alternatively, it is possible that the gene that confers weeping in ‘Traveller’ is dominant and that ‘Traveller’ is heterozygous at that locus. If this were the case, NC2011-1 may possess the recessive (non-weeping) form of the allele, which would render all FReciprocal crosses were made between gold leaf cultivars Hearts of Gold (entire gold) and JN2 (gold with green spots) to test for allelism of the gold leaf trait. We expected to recover either all green leaf  or all gold leaf  progeny from these crosses, but both green and gold leaf progeny were recovered, contradictory to a simple affirmation or rejection of allelism. In addition, two other leaf color phenotypes were observed. The bleached phenotype, described earlier in the manuscript, was recovered, as well as a fourth category, designated as chartreuse. Plants classified as chartreuse exhibited a cotyledon color that was intermediate between the gold and bleached categories. Chartreuse plants showed very light gold color in mature leaves (RHS greyed-yellow group 160A). Interestingly, cotyledon color varied considerably among segregating offspring, and appeared to be highly associated with leaf color, hence progeny were initially placed into the four phenotypic categories  based on cotyledon color. Plants were then grown on for 2–4 months and scored again based on leaf color , so that1 progeny originally designated in the cotyledon stage as green maintained this phenotype; however, a small percentage was later determined to belong to either the gold or chartreuse phenotypes. A small percentage of the progeny scored initially as gold were later determined to belong to either the green or chartreuse categories.The inherent difficulty of accurately scoring progeny at the cotyledon growth stage is illustrated by the change in frequency of progeny in each category upon final scoring of leaf color . The majThe majority of progeny classified initially in the cotyledon stage as chartreuse developed into plants with very light gold-colored leaves and an airbrushed overtone of very small, numerous, light green spots, similar to but distinct from the ‘mottled’ phenotype of ‘JN2’. Of the bleached progeny derived from ‘JN2’ × ‘Hearts of Gold’, 56% proved to be seedling-lethal. The remaining bleached progeny that survived past the seedling stage in the greenhouse ultimately developed into plants later reclassified as chartreuse. Upon placement in a field setting, all chartreuse segregants showed significant leaf burn and perished. These results suggest that plants classified as chartreuse may simply have a different degree of expression of the bleached phenotype. A moderate number of progeny in this study exhibited considerable phenotypic instability, demonstrating green and gold sectoring on cotyledons and/or leaves of individual plants . This inMirabilis jalapa L., a species known for transposon-mediated variegation.8 The mutagenic nature of transposons can be suppressed by small interfering RNA’s, especially in gametes that could transmit transposed elements to the next generation. Also, both mobility and expression of TEs can be transiently activated in the vegetative nuclei (tube nuclei) of pollen, which can ultimately lead to new somatic transpositions.9 The bleached, green, and chartreuse phenotypes recovered from hybridizations involving ‘Hearts of Gold’ and ‘JN2’ could be the result of such transient activation. TE activity in pollen of ‘Hearts of Gold’ or ‘JN2’ could cause unpredictable transmission of the gold leaf phenotype in different genetic backgrounds. It is possible the bleached and chartreuse progeny recovered in these families were gold leaf segregants whose phenotypes were each altered by TE activity in a different way.Progeny that were generated through reciprocal crosses of these two gold leaf parents did not conform to ratios that would be expected from simple allelic or non-allelic inheritance patterns. Consistent with families generated for the gold leaf inheritance study derived from ‘Hearts of Gold’, reciprocal crosses of ‘Hearts of Gold’ and ‘JN2’ yielded not only green leaf and gold leaf progeny, but bleached and chartreuse progeny as well . One wouCercis canadensis have been documented. The purple leaf phenotype is controlled by a single recessive gene (pl1pl1) in ‘Forest Pansy’ allelic to the purple leaf gene in ‘Greswan’. Weeping architecture in ‘Covey’ is controlled by a single recessive gene (wp1wp1), non-allelic to the mutation conferring weeping architecture in ‘Traveller’. Inheritance of the variegated leaf trait in ‘Silver Cloud’ and ‘Floating Clouds’ revealed that variegation in ‘Silver Cloud’ is controlled by a single recessive nuclear gene (var1var1), while variegation in ‘Floating Clouds’ is controlled by cytoplasmic factors. The double-flowered phenotype of ‘Flame’ is controlled by a single dominant gene (Df1Df1). Inheritance of the gold leaf phenotype found in ‘Hearts of Gold’ and ‘JN2’ is less well understood but likely the result of one major recessive gene. The gold leaf phenotype in both ‘Hearts of Gold’ and ‘JN2’ was transmitted both paternally and maternally. The genes controlling gold leaf in these two cultivars are likely allelic, but this could not be definitively determined. Phenotypic instability in leaf color observed in F2 progeny derived from ‘Hearts of Gold’, and from F1 progeny derived from ‘Hearts of Gold’ × ‘JN2’ is highly suggestive of TE activity, which could explain the segregation distortion and range of phenotypic variation in leaf color revealed in hybridizations involving ‘Hearts of Gold’ and ‘JN2’. It is possible that the bleached, mottled, and chartreuse phenotypes recovered in families derived from these two cultivars represent variable expression of the gold leaf phenotype altered by TE activity and genetic background.The modes of inheritance for several phenotypic mutations in


Mixed convection peristaltic flow of Jeffrey nanofluid in a channel with compliant walls is addressed here. The present investigation includes the viscous dissipation, thermal radiation and Joule heating. Whole analysis is performed for velocity, thermal and concentration slip conditions. Related problems through long wavelength and low Reynolds number are examined for stream function, temperature and concentration. Impacts of thermal radiation, Hartman number, Brownian motion parameter, thermophoresis, Joule heating and slip parameters are explored in detail. Clearly temperature is a decreasing function of Hartman number and radiation parameter. Peristaltic activity has great value in many physiological processes and industries. Peristalsis can occur due to contraction and expansion of flexible boundaries. In other words this activity includes passing down, mixing and transporting materials through contraction or expansion of the waves propagating along the channel walls. It has wide applications in medical industry and chemical processes. Typical examples in this direction include in distillation towers and fixed-bed reactors, urine transport from kidney to bladder through the ureter, transport of lymph in the lymphatic vessels, swallowing food through the esophagus, the movement of chyme in the gastrointestinal tract, ovum movement in the fallopian tube, transport of corrosive fluids, sanitary fluid transport and blood pumps in heart lung machine etc. The worms utilize peristalsis for locomotion. Latham  and ShapMixed convection occurs in vertical channels for improvement of cooling systems in engineering. Analysis of heat transfer with MHD and mixed convection in vertical channels has great applications in solar energy collection, chemical reactions and cooling systems. Sheikholeslami et al.  analyzedPeristaltic transport has not been conducted well in connection with elastic behavior of the walls. Wall properties such as elastic tension and damping are of immense importance in practical circumstances. Graphical results are plotted to analyze the behavior of sundry parameters on temperature, velocity, nanoparticle concentration and heat transfer coefficient.d1. The sinusoidal wave is propagating along the walls of the channel with wavelength λ and constant speed c. The axial and transverse directions are indicated by x and y respectively. Let y = −η and y = +η shows the left and right positions of the channel boundaries  for Jeffrey material isS represent extra stress tensor, λ1 shows the ratio of relaxation to retardation times, λ2 the retardation time, p the pressure, I the identity tensor, μ the coefficient of viscosity, u, v) are the components of velocity. The equations governing the flow are given byqr is given byσ* is the Stefan–Boltzmann constant having numerical value 1.380648 × 10−23JK−1 and k* is the mean absorption coefficient. We assume that the temperature difference within the flow is sufficiently small. Hence expanding T4about T0 and neglecting higher order terms one obtainsρf is the density of the nanofluid, ν the kinematic viscosity, α the thermal diffusivity, σ the thermal conductivity, Sxx, Sxy, Syy the components of extra stress tensor, DB the Brownian motion coefficient, DT the thermophoretic diffusion coefficient and τ1 the elastic tension, m1 the mass per unit area, d1 the coefficient of viscous damping, β1, β2, β3 the velocity, thermal and concentration slip parameters respectively, Tm the mean temperature, T1 and C1 the temperature and the concentration at the right wall respectively while T0 and C0 the temperature and the concentration at the left wall respectively.We consider two-dimensional flow of an incompressible Jeffrey nanofluid in a symmetric channel of uniform thickness 2ries see . A magneψ by the definition [Qr the local nanoparticle Grashoff number and Br = PrEc the Brinkman number, Pr the Prandtl number and Ec Eckert number. Heat transfer coefficient in non-dimensional form is given byIntroducing the following non-dimensional quantities:finition :u=∂ψ∂y,0,aty=±η,E1∂3∂x3+The purpose of this portion is to predict the behaviors of velocity, temperature, nanoparticle concentration and heat transfer rate under the impact of emerging parameters. Hence the graphical results are obtained numerically through NDSolve in Mathematica. The relevant physical explanations are presented in this section.β1, the velocity increases. As fluid slip is the deviation in the angle at which the fluid leaves the channel. Therefore an increase in β1 causes non-uniform velocity distribution inside the channel (see β1 is that the resistance is reduced due to slip hence velocity increases. Increasing Grashoff number Gr decreases drag forces and hence velocity profile increases (see λ1 and local nanoparticle Grashoff number Qr (see M (see E1 and E2 while velocity profile decreases upon enhancement in E3 due to its viscous damping effect (see nnel see . The effases see . It is sr Qr see . Magnetiee M see . Due to fect see . For relβ2. Br on temperature. Brinkman number arises due to viscous dissipation which enhances the temperature. It is reasonable to say that rise in temperature is produced by the stress-reversal process that develops with an increase in β2 (see M (see Nb because it makes the motion of nanoparticles stronger (see Nt (see Nt. Thus nonlinear thermophoresis can cause contradictory results between thermophoretic and numerical analysis. That is why the numerical results develops the nonlinear temperature distribution with Nt similar to the study of Hayat et al. [Rn decreases the temperature (as noticed from E1 and E2 due to elastance of wall while it decreases for E3 as E3 shows oscillatory resistance (see n β2 see . The simn β2 see . Magnetiee M see . Here thnger see . Howevere Nt see . Since nt et al. . Temperaance see .β3 the nanoparticle concentration decreases (see λ1. An increasing behavior of nanoparticle concentration is seen with Brownian motion parameter Nb (see Nt (see E1 and E2 increased then concentration profile decreases while it increases for E3.ases see . Fig 4(br Nb see . Also nae Nt see . Fig 4(eZ. It has been observed that because of successive contraction and relaxation of peristaltic walls the heat transfer coefficient shows oscillatory behavior. For thermal slip parameter β2 the absolute value of Z decreases (see Rn enhances the heat transfer coefficient Z (see ases see . Heat trases see . Also lant Z see .Analysis is performed for the peristaltic flow of Jeffrey nanofluid in a channel with compliant walls partial slip and mixed convection. The major observations are listed below:λ1 on velocity and temperature is similar.Behavior of λ1.Concentration and temperature have reverse effect for Gr and local nanoparticle Grashoff number Qr enhance the velocity.Grashoff number Rn and thermophoresis Nt parameters have same effects on temperature.Qualitatively the radiation Brownian motion parameter enhances the temperature.E1 and E2 on velocity are similar. However the impact of E3 on velocity is opposite to that of E1 and E2.Effects of β1 on velocity and β2 on temperature are similar. However concentration decreases upon increasing slip parameter β3.Behaviors of M reduces the temperature and velocity.Hartman number Both temperature and heat transfer coefficient are increased for Prandtl number Pr.E1 and E2. However the role of E3 on concentration is reverse to that of E1 and E2.Concentration profile is decreasing function of


Synaptic transmission relies on precisely regulated and exceedingly fast protein-protein interactions that involve voltage-gated channels, the exocytosis/endocytosis machinery as well as signaling pathways. Although we have gained an ever more detailed picture of synaptic architecture much remains to be learned about how synapses are maintained. Synaptic chaperones are “folding catalysts” that preserve proteostasis by regulating protein conformation (and therefore protein function) and prevent unwanted protein-protein interactions. Failure to maintain synapses is an early hallmark of several degenerative diseases. Cysteine string protein (CSPα) is a presynaptic vesicle protein and molecular chaperone that has a central role in preventing synaptic loss and neurodegeneration. Over the past few years, a number of different “client proteins” have been implicated as CSPα substrates including voltage-dependent ion channels, signaling proteins and proteins critical to the synaptic vesicle cycle. Here we review the ion channels and synaptic protein complexes under the influence of CSPα and discuss gaps in our current knowledge. Drosophila melanogaster, CSPα KOs that survive to adulthood demonstrate temperature-sensitive paralysis, uncoordinated movement, shaking and early death  is a presynaptic vesicle protein with neuroprotective activity. In humans, mutations in the DNAJC5 gene encoding CSPα that produce heterozygous CSPα point mutations or point deletions cause autosomal-dominant, adult onset neuronal ceroid lipofusinosis (ANCL), a neurodegenerative disorder characterized by accumulation of lysosomal cellular debris  located between helices II and III of CSPα’s four α helical J domain creates a loss-of-function mutant that does not activate Hsc70  proteins are fundamental to presynaptic vesicle-release events and for that reason have been closely scrutinized as possible CSPα “clients”. The t-SNARE, SNAP25  expression is decreased in CSPα KO mice  channels are ∼2.5 fold higher in the brain of CSPα null mice compared with age-matched wild types  also elicits elevation of BK channel expression and macroscopic current density  as well as gain-of-function . Consistent with this notion, CSPα heterozygote mice do not show neurodegeneration while ANCL patients show adult-onset neurodegeneration most likely due to mislocalized/oligomerized mutant CSPα chaperone activity outside the presynapse. Do changes in BK channel activity link to neurological disorders or neurodegeneration? Several studies have reported that alterations in the expression and function of BK channels give rise to neural dysfunction. For example, genetic deletion of BK channel subunits in mice  and rapidly progressing Alzheimer’s disease caused by presenilin 1 mutations (Dolzhanskaya et al., Clearly, the dysfunction of CSPα is linked to undesired consequences. Neurodegenerative diseases such as Alzheimer’s disease and Parkinson’s disease show a characteristic loss of neurons and synapses (Muchowski and Wacker, When CSPα is compromised, protein surveillance and proteostasis mechanisms in the neuron fail and the integrity of pre-synaptic terminals is compromised. The field is now poised to tackle in detail the pathogenic sequence of events responsible for activity-dependent neurodegeneration in the absence of CSPα chaperone activity. The emerging detailed molecular blueprint will undoubtedly serve investigators well in the development of therapeutics that protect against synaptic loss in neurodegenerative disorders.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.


Here we present the data on the energy-band-gap characteristics of composite nanoparticles produced by modification of the amorphous potassium polytitanate in aqueous solutions of different transition metal salts. Band gap characteristics are investigated using diffuse reflection spectra of the obtained powders. Calculated logarithmic derivative quantity of the Kubelka–Munk function reveals a presence of local maxima in the regions 0.5–1.5 eV and 1.6–3.0 eV which correspond to band gap values of the investigated materials. The values might be related to the constituents of the composite nanoparticles and intermediate products of their chemical interaction. Specifications TableValue of the data●The data reveals a complex configuration of electronic zones for the products obtained by soft chemistry methods such as modification of layered potassium polytitanate particles in aqueous solutions of transition metal salts.●This data attributes band gap values of the modified potassium polytitanates to the particular transition metal salt chosen for the modification.●The data can be applied to select the materials with optimal electron zones configuration for their application in different electronic devices.DataThe dataset consists of energy-band-gap characteristics of the potassium polytitanate nanoparticles modified in the aqueous solutions of transition metal salts of organic acids including Cu(II), Fe(II), Co(II) oxalates, Zn formate, as well as Cr(II) and Ni(II) acetates at pH=5–6. The data are obtained using modified Kubelka–Munk spectral method which allows recognizing a presence of particles with different energy-band-gap characteristics.1α(E)·E}n=f(E) have been constructed, where E is the photon energy and α(E) is the absorption coefficient replaced for optically dense systems by the Kubelka–Munk function F(E). The F(E) values is determined in accordance with R(E) by the Eq. The data on energy-band-gap characteristics are obtained using spectral method described in our previous work E)=d{ln[F(E)E]}/dE allows reliable estimation of Eg taking into account that the inclusion of the interband absorption at E≥Eg must be accompanied by the appearance of the local maximum in Δ(E) corresponding to the conditions of E=Eg. Discrepancies between Eg estimations obtained using the traditional Tauc plot extrapolation method and the proposed approach do not exceed 0.02 eV. If a system consists of several kinds of particles, each type of particles characterized with similar electron structure can be described as related to the specific local maximum.Determining local maxima of a logarithmic derivative quantity defined as Δ in the aqueous solutions of copper, iron, nickel, zinc, chromium and cobalt salts of organic acids are investigated using the abovementioned experimental method.22:K2O molar ratio of the powder corresponded to 4.05:1.00. The PPT powder was modified according to the following route −3 M aqueous solution of the corresponding transition metal salts. The obtained suspension was stirred for 8 h and then the obtained product was separated by centrifugation and dried at 60 °C for 4 h. The chemical composition of the prepared powders was determined in the oxide form using an energy-dispersive X-ray fluorescence spectrometer and reported in The amorphous potassium polytitanate powder , consisted of platy nanoparticles with a mean diameter of 273±125 nm and a thickness of 5–15 nm was utilized in the experiments as raw material. The TiO3 in disks of 6 mm in diameter and 2.0±0.1 mm of thickness and used to investigate their optical reflection spectra.Further, modified PPT powders (PPTM) were compacted to density 2.25±0.15 g/cm3F(E) and corresponding Δ(E) functions for different PPT powders modified in aqueous solutions of transition metal salts (PPTM). The insets in F(E) functions. Fig. 2The measured diffuse reflection spectra has been processed to obtain the Kubelka–Munk functions E) dependences obtained for different PPTM. In order to minimize the influence of noise in the initial spectral data on the results of Δ(E) calculations, these data have been preliminarily smoothed using the Savitzky–Golay second-order filter with a 15-point window. The applied spectral method does not allow estimating the type of interband electron transition (direct or indirect); however, it allows assessing the data on energy-band-gap characteristics for the PPTM nanoparticles.E) plots for different PPTM possess two groups of peaks taking place in the obtained Δ(E) patterns. The 1st group is related to relatively high values of the photon energy and has higher intensity in comparison with another . The 2nd group appearing at lower photon energies might be characterized by higher intensity and has been observed for PPT modified with cobalt, iron and chromium salts.The Δ(Taking into account that a presence of multiple maxima in each group of peaks could be explained by structural features of different particles as well as their size


We get more accurate result as we increase the order of approximations. Effects of different parameters on the velocity, temperature and concentration distributions are sketched and discussed. Comparison of present study with the previous published work is also made in the limiting sense. Numerical values of skin friction coefficient and Nusselt number are also computed and analyzed. It is noticed that the flow accelerates for large values of Powell-Eyring fluid parameter. Further temperature profile decreases and concentration profile increases when Powell-Eyring fluid parameter enhances. Concentration distribution is decreasing function of homogeneous reaction parameter while opposite influence of heterogeneous reaction parameter appears.This article examines the effects of homogeneous-heterogeneous reactions and Newtonian heating in magnetohydrodynamic (MHD) flow of Powell-Eyring fluid by a stretching cylinder. The nonlinear partial differential equations of momentum, energy and concentration are reduced to the nonlinear ordinary differential equations. Convergent solutions of momentum, energy and reaction equations are developed by using homotopy analysis method (HAM). This method is very efficient for development of series solutions of highly nonlinear differential equations. It does not depend on any small or large parameter like the other methods i. e., perturbation method,  Non-Newtonian fluids play key role in various industrial processes such as natural products, multiphase mixtures, biological fluids, food products, agricultural and daily food wastes. Due to its highly utility and wide range of applications in industries researchers have keen interest to explore the characteristics of non-Newtonian fluids. The non-Newtonian fluids have nonlinear relationship between stress and rate of strain. Such fluids cannot be predicted by a single constitutive equation due to their diverse characteristics. One of the non-Newtonian fluids is the Powell-Eyring fluid which was proposed by Powell and Eyring in 1944. It has several advantages i.e., (i) It is derived from kinetic theory of liquid rather than the empirical relation. (ii) At low and high shear stresses Powell-Eyring fluid behaves as a Newtonian. The flow of the non-Newtonian fluids plays significant role in various industrial, natural, engineering and geophysical processes. These processes involve manufacturing of cooling system with liquid metals, MHD generators, accelerators, nuclear reactors, electric motors, blood flow measurements, pumps and flow meters etc. MHD flow through blood vessel has gained considerable attention in physiological processes. Due to such considerable applications scientists and researchers carried out magnetohydrodynamic flows regarding different physical phenomenon. Hayat et al.  developeIn current time the development of human society greatly depends on the energy resources. Researchers and scientists have stimulated in this area to develop advance energy resources and technologies so that solar energy could be utilized in a more easy and efficient way. In this regards it is desired to design and construct high rate of heating/cooling equipment machinery and various medical instruments and devices with high capability of chemical transport. Heat transfer in various natural and industrial process depend upon mechanism of heat transfer from wall to ambient fluid. Merkin  suggesteScientists and researchers are desired to develop and design some new catalytic processes which work at very high temperature. In these processes homogeneous and heterogeneous chemical reactions play significant role. Homogeneous and heterogeneous reactions are very complex involving consumption and production of reactant species both with in the fluid and on the catalyst surface at different rates. Such reactions involve in combustion, catalysis and bio chemical systems. Merkin  discusseThe main objective here is to disclose the characteristics of homogeneous-heterogeneous reactions in the MHD flow of Powell-Eyring fluid over an impermeable stretching cylinder. Heat transfer analysis is carried out with Newtonian heating and heat generation/absorption. Diffusion coefficients of both species are considered to be equal. Homotopy analysis method –29 is usβ0 is applied in the radial direction. Effect of induced magnetic field due to small magnetic Reynolds number is neglected. Further the effects of homogeneous- heterogeneous reactions and Newtonian heating are also considered. The heat produced is ignored during the irreversible chemical reaction. The homogeneous reaction for cubic autocatalysis can be expressed in following fashion:Consider the MHD two-dimensional boundary layer flow of Powell-Eyring fluid by a stretching cylinder. Heat transfer includes the salient features of heat generation/absorption. Uniform magnetic field A and B are denoted by a and b while k1 and ks are the rate constants. This irreversible reaction assures that the reaction rate is negligible in the external flow and at the outer edge of the boundary layer. Cylindrical coordinates are chosen such that z—axis is along the stretching cylinder and r—axis normal to it −1. Here second-order approximation of the sinh−1 function is consideredu = O(δ), r = O(δ), w = O(1) and z = O(1)) the continuity, momentum, energy and homogeneous-heterogeneous reactions equations are as follows:u and w denote the velocity components in the r− and z− directions respectively, U0 is the reference velocity, l is the characteristics length, ν is the kinematic viscosity, ρ is the density, cp is the specific heat, k is the thermal conductivity, T and T∞ are the temperatures of fluid and ambient respectively, β0 is strength of applied magnetic field, σ1 is electrical conductivity, Q is the coefficient of heat generated or absorbed per unit volume, we is the stretching velocity, hs is the heat transfer coefficient, DA and DB are the respective diffusion coefficients and a0 is constant. Using the below mentioned transformationsγ is the curvature parameter, M and λ the fluid parameters, Ha2 Hartman number, Pr Prandtl number, K gives the strength of measure of homogeneous reaction, δ heat absorption (δ < 0) or heat generation (δ > 0) parameter, α conjugate parameter for Newtonian heating, Sc the Schmidt number and Ks measures the strength of heterogeneous reaction. The parameters are defined as follows:DA and DB are assumed same i. e. δ* = 1, here we have  is embedding parameter and ℏf, ℏθ and ℏΦ are the non-zero auxiliary parameters.Ai (i = 1–7) have the values:rocedure  the soluf, ℏθ and ℏΦ are −1.5 ≤ ℏf ≤ −0.1, −2.5 ≤ ℏθ ≤ −0.1 and −1.9 ≤ ℏΦ ≤ −0.8 respectively.For the series solutions of momentum, energy and homogeneous-heterogeneous reactions equations by homotopy analysis method, the convergence region is essential. Convergence region of the series solutions depend upon the auxiliary parameter ℏ. Therefore we have plotted the ℏ-curves in Figs Ha2 on the velocity profile f′(η). Here both velocity and layer thickness decrease for larger values of Hartman number Ha2. In fact an increase in values of Hartman number Ha2 shows stronger Lorentz force which offers more resistance to the fluid motion and thus the velocity profile f′(η) decreases. Ha2 on temperature profile θ(η). It is observed that both temperature and thermal boundary layer thickness increase for larger values of Hartman number Ha2. η). The concentration profile Φ(η) is found to decrease when Hartman number Ha2 increases. γ on the velocity profile f′(η). It is noted that for larger curvature parameter γ the velocity profile and momentum boundary layer thickness first decrease and then increase. This is due to the fact that for increase in curvature parameter γ the radius of cylinder decreases and consequently less resistive force occurs for the fluid and the velocity profile f′(η) increases. Similar behavior is observed for temperature profile θ(η) (see θ(η) decreases near the surface of cylinder while it increases away from the surface. For higher values of curvature parameter γ, the radius of cylinder decreases and consequently less particles are sticky to the surface which are responsible for heat transfer through conduction. Therefore temperature profile decreases near the surface of cylinder. It is also observed that temperature profile is higher in case of flat plate when compared with the cylinder. γ on concentration profile Φ(η). It is noted here that through larger curvature parameter γ, the thermal boundary layer thickness first decreases and then increases. For curvature parameter γ = 0 the problem reduces to flat plate. M. Both velocity and associated boundary layer increase via M. As M increases the fluid becomes less viscous which enhances the fluid velocity. However the temperature and thermal boundary layer thickness decrease via M . Clearly the concentration profile Φ(η) is an increasing function of M. Effect of Prandtl number Pr on temperature profile θ(η) is displayed in δ on temperature profile θ(η). It is observed that for increase in heat generation parameter δ the thermal boundary layer and temperature of the fluid are enhanced. In fact more heat is produced due to increase in heat generation parameter. Hence temperature profile θ(η) increases. α on temperature profile θ(η). Here temperature and thermal boundary layer thickness are increasing functions of conjugate parameter α. Higher values of conjugate parameter results in higher heat transfer coefficient which consequently enhances the fluid temperature and also the thermal boundary layer thickness. Effect of strength of homogeneous reaction K on concentration distribution Φ(η) is plotted in η) decreases while boundary layer thickness increases for higher values of strength of homogeneous reaction parameter. Behavior of strength of heterogeneous reaction parameter Ks on concentration distribution Φ(η) is computed in η) increases for higher values of heterogeneous parameter Ks. Influence of Schmidt number Sc on concentration profile Φ(η) is shown in η) is observed for higher values of Schmidt number Sc away from the surface of cylinder. It is due to the fact that Schmidt number Sc is the ratio of momentum diffusivity to mass diffusivity as a result higher values of Schmidt number Sc correspond to small mass diffusivity. Hence concentration profile Φ(η) decreases. th orders of approximations are sufficient for the convergence of required equations. f′′(0) with the previous published results in the limiting case of γ = 0 and Ha = 0. It is concluded that both the results are in good agreement. It is analyzed that f′′(0) shows decreasing behavior for higher values of M while opposite behavior is observed for increasing λ. γ = 0 and Ha2 = 0. It is evident that both the results match in good agreement. Skin friction coefficient increases with an increase in M and it decreases with λ. Therefore small values of M and large values of λ can be used for the reduction of skin friction coefficient. γ, fluid parameter M, Prandtl number Pr and conjugate parameter α while it decreases with Hartman number Ha2 and heat generation parameter δ. As rate of heat transfer is high for large values of curvature parameter γ and fluid parameter M so these parameters can be used as coolant factor. Thus it is noted that cylindrical shape devices with large curvature i.e, with small radius have high rate of heat transfer. γ and Hartman number Ha2 while it decreases with increase in the values of fluid parameter M. f′′(0) for different methods with previous published works [Interest in present section is to examine the effects of different parameters on the velocity, temperature and concentration profiles. θ(η) see . It is aia M see . This ised works , 31. TheHere the influence of homogeneous-heterogeneous reactions in the flow of Powell-Eyring fluid by a stretching cylinder is discussed in the presence of heat generation/absorption and Newtonian heating. Main points through convergent solutions are as follows:M while the temperature and thermal layer thickness decrease. Fluid parameter inversely relates the viscosity of fluid. As a result fluid becomes less viscous as M increases. Thus the temperature profile decreases. This parameter can be used to control the heat transfer in the industrial and engineering processes. The fluid parameter also plays important role in polymer solutions, paint, flow of blood, flow of liquid metals etc.The velocity profile increases for larger values of fluid parameter The temperature field near the surface of cylinder decreases for lager values of curvature parameter. Further the heat transfer through conduction reduce for higher values of curvature parameter due to reduction of contact area of fluid particles. Thus this parameter can be used as a cooling agents in industrial processes.The temperature and thermal boundary layer thickness are enhanced when Hartman number increases. Physically the Lorentz force appeared due to the applied magnetic field which acts as a retarding force and causes the reduction in the flow and enhancement in thermal boundary layer thickness. It has significant applications in industrial manufacturing processes such as plasma studies, petroleum industries, magneto-hydrodynamics power generator, cooling of nuclear reactors, boundary layer control in aerodynamics, glass fiber production and paper production.Homogeneous and heterogeneous parameters have opposite behavior for concentration profile. It is observed concentration at the surface decreases as the strength of the heterogeneous reaction increases. It is due to inverse relation with mass diffusivity. Such reactions occur in combustion, catalysis and bio chemical systems.M and inversely relates with the fluid parameter λ. Hence smaller values of M and larger values of λ can be used for the reduction of skin friction coefficient. Larger values of curvature parameter λ and fluid parameter M have high rate of heat transfer.Skin friction coefficient directly relates with fluid parameter It is hoped that the present investigation serves as impetus for the researchers and scientists to develop catalytic processes involving homogeneous-heterogeneous reactions which can be operated at high temperatures such as reactions occurring in combustion, bio chemical systems etc. This analysis can be extended to variable sheet thickness, melting heat transfer and Cattaneo-Christov heat flux.


Many cellular functions rely on DNA-binding proteins finding and associating to specific sites in the genome. Yet the mechanisms underlying the target search remain poorly understood, especially in the case of the highly organized mammalian cell nucleus. Using as a model Tet repressors (TetRs) searching for a multi-array locus, we quantitatively analyse the search process in human cells with single-molecule tracking and single-cell protein–DNA association measurements. We find that TetRs explore the nucleus and reach their target by 3D diffusion interspersed with transient interactions with non-cognate sites, consistent with the facilitated diffusion model. Remarkably, nonspecific binding times are broadly distributed, underlining a lack of clear delimitation between specific and nonspecific interactions. However, the search kinetics is not determined by diffusive transport but by the low association rate to nonspecific sites. Altogether, our results provide a comprehensive view of the recruitment dynamics of proteins at specific loci in mammalian cells. During transcription, replication and repair, DNA-binding proteins must find specific interaction sites hidden within a vast excess of genomic DNA. Here the authors use single-molecule tracking to quantitatively determine the contributions of the different processes that underlie target search in human cells. Understanding the mechanisms by which DBPs find their target sites ∼10 bp long) within genomes made of millions to billions of base pairs, and quantifying the associated search kinetics, is pivotal to analyse biochemical reactions and their regulation in living cells0 bp longHere we quantitatively investigate the TS of DBPs in human cells. We use Tet repressors (TetRs) as searchers in the nucleus of human cells in which a gene array serves as target locus. With this model system, we can unequivocally distinguish the role of specific and nonspecific interactions. Thereby, we identify the role of FD in the TS and measure transport and binding parameters underlying the search kinetics. We find that nonspecific binding times are broadly distributed, with no clear delimitation between specific and nonspecific interactions. In addition, we measure at the single-cell level the association kinetics to the target locus. Importantly, the association rate is not limited by transport but, instead, by the binding to nonspecific DNA sequences. Altogether, our results provide a quantitative description of the TS dynamics and shed a new light on the factors controlling the search kinetics.Since the initial observations of the rapid mobility of nuclear factors1718tetO) with high affinity  from a linear fit of the initial points of the mean square displacement (MSD). The broad distribution of DInst could be sorted into three different mobility categories  of freely diffusing proteins characterized by linear MSD curves  with sublinear  characterized by a greatly reduced mobility and flat MSD curves  and tracked single proteins at 197 frames per second with ∼25 nm localization accuracy . In inditegories : a fast D curves . To furtcurves 30. Importacurves 30 than in curves 30 confirmecurves 30. Thus, wD3) closely matched those of chromatin itself, as observed by tracking chromatin-bound markers such as histones H2B22−1) or when saturating the TetR DNA binding domain (DBD)–before injection— with short double-stranded DNA fragments containing the specific tetO sequence . It should be noted that on Dox treatment or co-injection with tetO oligos, the diffusion coefficients of the two mobile populations . This might be due to some residual very rapid TetR–DNA interactions via the protein DBD, which are instead completely abolished by steric hindrance in the case of tetO co-injection. Nevertheless, the fact that in this latter case the intermediate population is still present indicates that the subdiffusive as well as the confined motion observed for the intermediate population is not only mediated by DNA interactions via the DBD of TetR but instead might depend on other factors such as protein–protein interactions (including crowding effects34per se in controlling the diffusivity even of inert tracers36The diffusive properties of quasi-immobile molecules (characterized by the diffusion coefficient f1+f2) ∼75% of diffusing proteins . This leads to τ3D∼3τ1D and places a constraint on the relative values of the dissociation rate (1/τ1D) and of the association rate (1/τ3D). Note that with current single-molecule tracking techniques, no direct evidence can be obtained by imaging on local sliding movement (or absence thereof) of the protein during nonspecific binding events.Overall, we concluded that the molecules partitioned between those diffusing in the nucleoplasm (fast and intermediate populations) and those interacting nonspecifically with DNA (population of quasi-immobile proteins). The total fraction  the time course of the instantaneous diffusion coefficient computed over an 80ms running window  over at least two consecutive images. For each data set, we computed the survival probability (SP): τ (namely the complementary cumulative probability). The full SP, that includes the long binding events along the short ones, was obtained by renormalizing the SPs measured in time-lapse movies with the value of the SP obtained for continuous imaging at 1 s (τSPE∼60 s) of TetR to tetO as measured in vitro  and temporal (10 ms) resolution of our imaging system. Yet, while hopping events possibly occur, they cannot account for the broad distribution of nonspecific binding times . On the 40tetO sequence to the human genome and assess the possible existence and abundance of quasi-consensus sites for TetR. While the full length recognition sequence is not present in the human genome, we found thousands of sites that only partially differ from the tetO sequence  sites. Furthermore, not only quasi-consensus sequences could behave as decoy sites but also certain repeat symmetries (outside of the specific binding sites) can control DNA-binding preferences, as recently shown by high throughput protein-DNA binding analysisτRS∼158 ms) to stable binding on sites that only partly differ from the 19bplong tetO specific sequence  algorithmsequence . For ins lengths . Even thsequence .τ1D, we numerically integrated the survival probability SP distribution and found τ1D to be ∼2 s, consistent with FRAP observations ∼0.12 s−1. Importantly, τ3D is much longer than 1/DacDNA ∼10−5 s, the time estimated for a diffusion-limited nonspecific association in the nucleus (with a=1 nm and the diffusion coefficient D on the order of D1). The high value of τ3D—or equivalently, the low association rate 1/τ3D—is possibly due to the inaccessibility of a large fraction of genomic DNA, to the inefficient binding of TetR to non-cognate sequences or to a combination thereof.To evaluate the mean nonspecific binding time rvations . Given t−1) to U2OS 2-6-3 cells stably expressing RevTetR-GFP, we observed an accumulation of RevTetR-GFPs at the target locus kObs scaled linearly with c  × 104 M−1 s−1. Thus, the average time for a single individual TetR protein to bind to the array in a nuclear volume of ∼500 μm3 is on the order of 3 × 106 s , during which it visits ∼105 nonspecific sites.Having obtained a detailed view of the mechanisms governing protein mobility away from the specific sites, we next aimed to directly measure the search rate or, equivalently, the association rate constant of DBPs to the target locus in living cells. To this end, we used the Reverse TetR (RevTetR), a TetR point mutant for which DNA binding is inversely regulated by Dox44et locus . The onsocus −1, , ruling −1, kObs . In eachN binding sites that appear clustered within an approximately spherical locus with radius rt∼350 nm, as determined by super-resolution microscopy imaging =6 μm2 s−1 that takes into account the slowdown due to intermittent nonspecific binding away from the locus. For simplicity, we assumed that the binding sites (each of radius a=1 nm) are uniformly distributed within the sphere. The association rate constant can then be written:Given the unexpectedly low value measured for the association rate constant, we next focused on modelling in more details the search kinetics. In our experiments, the target is composed of  imaging . To modeκ is the probability per unit time to bind to a target sequence when the searcher is within the locus , λ is very large (≫ D/a2) such that κ is equal to 4πDa/v. Since ka reduces to 4πDrt, the value for an absorbing sphere of radius rt. Given the measured values of D and rt, ka should be ∼2 × 109 M−1 s−1, more than four orders of magnitude larger than experimentally observed. This suggests that the binding is very inefficient at the target sites (consistently with our measurement of the nonspecific association rate 1/τ3D) and that the proteins need many encounters before stably associating to DNA. Importantly, in the low binding efficiency regime (λ<<D/a2), ka≈(4π/3)λNa3 is no longer determined by the transport properties.Here To further verify that the association kinetics is reaction limited, we expressed the LacI fused to the transactivator domain VP16 ref.  in U2OS tetO sites. To probe the potential role of 1D motion, we measured the search kinetics in the case of a different organization of the target locus using U2OS 4A cells. In this case, the target locus appeared as a ∼200nm diameter spot (4 M−1 s−1 (tetO sites (Ni the number of inserts (200 versus 30) rather than N the number of sites  as would be expected for a reaction limited by the specific binding efficiency to the target. This observation means that the search process cannot be purely 3D and suggests that prior to association to specific sites, TetRs slide along the DNA flanking regions before reaching their target. As reported for LacI proteins in E. colitetO sites in each insert (23 bp both in U2OS 2-6-3 and U2OS 4A cell lines) while remaining well below the distance between inserts (∼16.5 kbp in U2OS 2-6-3 cells and ∼4 kbp in U2OS 4A cells). To evaluate the plausibility of this scenario, we estimated the sliding length τRS=158 ms and assuming a 1D diffusion coefficient DSL∼105–106 bp2 s−1, similar to the values reported for several different DBPs diffusing along naked B-DNA9The observation of nonspecific binding events in individual trajectories raised the possibility that the searchers did not reach the target site solely via 3D motion but also using a local 1D exploration at the vicinity of the ter spot  and we mtO sites . In otheτ3D. Once nonspecifically attached to DNA, we hypothesized that the protein can locally scan neighbouring sequences, and eventually bind to a specific site with probability p if the sliding excursion overlaps with an insert. Indeed, as recently shown, proteins do not necessarily associate perfectly as they slide over their specific siteska can then be written as  and 24 MS2 stem loops. We also used U2OS 4A cellstetO binding sites  with 10% (v/v) fetal bovine serum , 1% Pen/Strep  and 1% GlutaMAX . When required, cells were transiently transfected by lipid vesicles fusion  12–24 h before experiments (Experiments were conducted on human osteosarcoma (U2OS)-derived cells containing at a single locus in the genome different inserts of specific target sites. In particular, we employed U2OS 2-6-3 cellsng sites . In both−1. Typical recording were 50s long under wide-field laser illumination  at about 0.1 kW cm−2. Single-molecule trajectories were generated with the MatLab  script SLIMfast, which implements the Multiple-Target-Tracing algorithmN=5 cells). We calculated the MSD for each trajectory longer than eight frames and obtained the instantaneous diffusion coefficients DInst by unconstrained linear fit of the MSD curves between time lag 2 and 5  and acquired with a back-illuminated Electron-Multiplied Charge-Couple-Device (EM CCD) camera  with 5 ms exposure time at a rate of 197 frames sndance f .τTL=0.1, 0.5 and 1 s) to extend the observation window to longer times while preventing photobleaching to mask the long events. We localized particle positions as for continuous imaging and we considered as immobile the proteins that remained within 1 pixel for at least two frames. Next we calculated the survival probability SP(τ), that is, the probability of staying bound for time longer than τ. The numerical integration of the SP data yielded an estimate of τ1D∼2 s.  with different inter-frame times (τ1D∼2 s. .tetO sequence (TCC CTA TCA GTG ATA GAG A). To exhaustively score all sites, we increased the Expect value  until the total number of scores found by the algorithm plateaued. With an E-value of 50,000, we obtained 14,482 sites with 11 bp or longer similarity to the tetO sequence  was fitted with a purely diffusive model to determine the mean number of molecules in the excitation volume given by <NMol>=1/Gτ→0)( (ref. x error bars in The concentration →0) ref. . Three F−2 for the 561nm imaging laser and between 0 up to ∼102 kW cm−2 for the 405nm activation laser  and an adaptive optical system  placed in the detection pathway of the microscopeon laser . Super-ron laser  have beeHow to cite this article: Normanno, D. et al. Probing the target search of DNA-binding proteins in mammalian cells using TetR as model searcher. Nat. Commun. 6:7357 doi: 10.1038/ncomms8357 (2015).Supplementary Figures 1-35, Supplementary Tables 1-13, Supplementary Notes 1-11 and Supplementary References.TetR-Atto647N micro-injection and binding to the target siteDox-induced release from the target siteSingle-Particle-Tracking experimentsIndividual trajectories analysissptPALM experimentsFRAP experimentsTransient nonspecific binding events in individual trajectoriesRevTetR-GFP induction experimentsSuper-resolution images of the target sitesLacI behavior in mammalian cellsBLAST alignment of tetO to human genome results list