Genome-wide identification of CNGC genes in Chinese jujube (Ziziphus jujuba Mill.) and ZjCNGC2 mediated signalling cascades in response to cold stress.
BACKGROUNDS
Cyclic nucleotide gated channels (CNGCs) play multifaceted roles in plant physiological processes, especially with respect to signalling processes, plant development, and responses to environmental stresses. However, little information is known about the CNGC family in the large cosmopolitan family Rhamnaceae, which has strong tolerance to biotic and abiotic stresses.


RESULTS
In the current study, a total of 15 ZjCNGCs which located on 7 chromosomes were firstly identified in Chinese jujube (Ziziphus jujuba Mill.), the most important species of Rhamnaceae in terms of economic and ecological values. Phylogenetic analysis showed that these ZjCNGCs could be classified into four groups, ZjCNGC12 belonged to group IVA, and ZjCNGC13, 14, 15 belonged to group IVB. In addition, the paralogous and orthologous homology duplication of ZjCNGC15 occurred during the evolutionary process. The characteristics of ZjCNGCs regarding to exon-intron numbers and post-translational modifications showed diversified structures and functions. Motif composition and protein sequence analysis revealed that the phosphate-binding cassette and hinge regions were conserved among ZjCNGCs. Prediction of the cis-acting regulatory elements and expression profiles by real-time quantitative PCR analysis showed that some of the ZjCNGCs responded to environmental changes, especially ZjCNGC2, which was significantly downregulated in response to cold stress, and ZjCNGC4 was highly induced in response to cold, salt and alkaline stresses. ZjCNGC13 and 14 were highly induced in the phytoplasma-resistant cultivar and downregulated in the susceptible cultivar. Furthermore, ZjCNGC2 could be regulated by cAMP treatment, microtubule changes and interact with ZjMAPKK4, which suggested that cAMP and microtubule might play important roles in ZjCNGC2 mediated ZjMAPKK4 signalling transduction involved in cold stress.


CONCLUSIONS
The identification and classification analysis of ZjCNGCs were firstly reported, and some key individual ZjCNGCs might play essential roles in the response to biotic and abiotic stresses, especially ZjCNGC2 mediated ZjMAPKK4 signalling transduction involved in cold stress. This systematic analysis could provide important information for further functional characterization of ZjCNGCs with the aim of breeding stress-resistant cultivars.
['Wang|Lixin|L|', 'Li|Min|M|', 'Liu|Zhiguo|Z|', 'Dai|Li|L|', 'Zhang|Mengling|M|', 'Wang|Lili|L|', 'Zhao|Jin|J|', 'Liu|Mengjun|M|']
D020816:Amino Acid Motifs D002874:Chromosome Mapping D058639:Cold-Shock Response D054815:Cyclic Nucleotide-Gated Cation Channels D019143:Evolution, Molecular D018506:Gene Expression Regulation, Plant D010710:Phosphates D010802:Phylogeny D010940:Plant Proteins D015398:Signal Transduction D031957:Ziziphus
CNGCs Chinese jujube Signalling Stresses Phylogeny