Cloning And Functional Identification Of StCDPK22 Gene Of Potato

Plants and some protists contain a unique serine/threonine protein kinase,calcium-dependent protein kinase(CDPKs).The study found that the CDPKs gene participates in plant carbon / nitrogen metabolism cycles,stomatal movement,growth and development regulation,ion and water transport on the membrane,dynamic changes of the cytoskeleton,abiotic stress and biological stress response,etc.It will induced expression by stimulates such as auxin,drought,high salt,low temperature,pathogen invasion and mechanical damage.In this study,members of the potato StCDPKs gene family were identified through Hidden Markov models,the gene structure,conserved domains,phylogenetic evolution,transcription and expression patterns of StCDPKs were analyzed,and StCDPK22 genes was screened through RNA transcript analysis.Further,through bioinformatics,subcellular localization,over-expression and inhibited expression techniques,the biological characteristics and main functions of potato StCDPK22 gene were studied.The main research results obtained are as follows:1.A total of 25 StCDPKs genes were screened from the latest potato total protein sequence by the Hidden Markov Model.Combined with 2 genes included in NCBI,a total of 27 potato StCDPKs genes were obtained.Conservative domain analysis found that the 27 genes did not differ greatly in the number of gene exons-introns and conservative domains.27 StCDPKs genes are divided into four subgroups in evolution.The transcription and expression of 25 StCDPKs genes in different tissues and organs are different,and the transcription of 15 StCDPKs genes under different treatments is also significantly different.2.Bioinformatics analysis showed that the potato StCDPK22 gene has a total length of 2488 bp,is distributed on chromosome 10,and has 8 exons.The StCDPK22 protein contains 4 EF-hands and 524 amino acids.It is a neutral protein,and the protein is relatively stable.The sondary structure ? helix is mostly located at both ends of the protein with an average hydrophilicity coefficient of-0.527.Subcellular localization shows the protein localization in the cell membrane and nucleus.StCDPK22 interacts with multiple proteins in protein interaction analysis.3.The overexpression vector pBI121-StCDPK22 of potato StCDPK22 gene and the suppression expression vector pBI121-amiR were constructed,and two groups oftransgenic lines(OE and RNAi)were obtained by genetic transformation of potato.qRT-PCR detection showed that the expression of StCDPK22 gene in OE-2 increased by 38.6% compared with NT,while the expression of StCDPK22 gene in RNAi-2decreased by 7.7% compared with NT.4.Under PEG simulated drought treatment,with the degree of Drought intensify,the activities of Superoxide Dismutase(SOD),Peroxidase(POD)and Catalase(CAT)in non-transgenic(NT)and transgenic(OE,RNAi)plants are all to varying degrees Enhanced.At different PEG concentrations,the activity enhancement of SOD and CAT in OE-2 was about 11% and 15% more than NT,while the activity enhancement of SOD and CAT in RNAi-2 was about 9% and 6% less than NT.This indicates that when the potato is under drought stress,StCDPK22 plays a role in enhancing the antioxidant activity of the potato.It is speculated that StCDPK22 has a certain role in the resistance of the potato to drought or osmotic stress.