The CBL And CIPK Gene Family In Grapevine(Vitis Vinifera):Genome-wide Analysis And Expression Profiles In Response To Various Abiotic Stresses

Calcium is an important inorganic nutrient element of plants,which also acts as an intracellular messenger to participate in plant growth and development as well as the regulation of external environmental stimuli.For adapt to these biotic and abiotic stresses from the outside,plants build different signal transduction pathway systems to sensitize these stimuli and produce different responses.Under specific abiotic stresses conditions such as light,heat,cold,salt,drought or osmotic stress,plant hormones,and fungi induction,the calcium ions in the cytoplasm will show specific changes in concentration,specific time and specific cell location,these changes are called calcium signal.Specific stimulation of the calcium signal can be received by specific calcium receptor,and then interact with specific downstream protein continue to transfer the signal,then regulate a series of physiological and biochemical reaction process,to adapt or resist outside stresses.CBL(Calcineurin B-like protein)protein is a kind of pant specific Ca2+ sensor.CIPK(CBL-interacting protein kinase)can specifically interact with CBL protein as CBL-CIPK complex.The CBL-CIPK complex acting on the downstream target protein by phosphorylation,decodes a variety of calcium signals and regulates the related physiological and biochemical processes.CBL proteins contain four EF-hand domains for binding Ca2+,and CIPK proteins includes a conserved NAF/FISL domain that binding CBL.In the absence of binding to CBL,the regulatory domain of CIPK inhibits the kinase domain,after binding to CBL protein,the regulatory domain removed and activates the kinase domain of CIPK,and continues to transfer calcium signal to downstream protein.These two gene families or their interactions are widely responsive to various environmental stimuli and growth processes.However,the whole genome annotation and expression patterns of CBLs and CIPKs in grapevine are still unclear.The main contents of this study are composed of three parts:1)Using bioinformatics to identify the CBL and CIPK gene families in grapevine genome,chromosome location,gene structure analysis,phylogenetic tree construction and protein domain analysis.2)The expression profiles of 8 VvCBL and 20 VvCIPK genes under salt(NaCL,200mM),PEG(10%),low potassium(LK,100 ?M),cold(4 ?)and heat(42 ?)conditions were studied by real-time fluorescence quantitative PCR(qPCR).The expression patterns of 8 CBLs and 20 CIPK genes in grapevine growth and development were analyzed on the base of microarray data.3)The co-expression patterns of 8 VvCBL and 20 VvCIPK genes were studied by using bioinformatics and gene expression profile,and contrast with Arabidopsis thaliana co-expression relationship.The detail results are as follows:1.8 CBL and 20 CIPK genes were identified in grapevine genome,and divided into four and five subfamilies,respectively,based on phylogenetic analysis,and validated by gene structure and the distribution of conserved protein motifs.Four(50%)out of eight VvCBLs and eight(40%)out of twenty VvCIPKs were found to be derived from tandem duplication,and five(25%)out of twenty VvCIPKs were derived from segmental duplication,indicating that the expansion of grapevine CBL and CIPK gene families were mainly contributed by gene duplication,and interestingly,all duplication events between CIPK genes only detected in intron poor clade.2.Expressional analyses of VvCBL and VvCIPK genes based on microarray and qRT-PCR data performed overall expression patterns of VvCBLs and VvCIPKs in response to both various abiotic stimuli and at different development stages.Found that the function of VvCBLs and VvCIPKs become diversified during the evolution process.For example,VvCBLIOa and VvCBL10b of subfamily I,were derived from tandanm duplication,were up-regulated under salt,PEG and cold stress.However,VvBL10a was down-regulated and VvCBL10b was up-regulated under low potassium stress.Suggesting that the functional of these two genes changes during their evolution process.In addition,VvCBL8 was up-regulated under almost all stress conditions,but VvCIPK35 was down-regulated under almost all stress conditons.3.According to the Pearson Correlation Coefficient of VvCBL and VvCIPK genes,found that VvCBL and VvCIPK have more strong correlation gene pairs under abiotic stresses but less strong correlation gene pairs in development process.Suggesting that CBL-CIPK complex play more important role in abiotic stress.Co-expression profile suggest that divergent mechanisms might exist between Arabidopsis and grapevine.Our results will facilitate the future functional characterization of individual VvCBLs and VvCIPKs.