Function Analysis Of Potassium Channel Gene CmSKOR From Melon And Trans-Conduct It Into Arabidopsis Thaliana

Melon(Cucumis melo L.)is an important commercially crop that richen in potassium ions(K~+),efficient absorption and utilization of potassium ions is conducive to promoting the growth and development of it.Shaker-like potassium channels play important roles in K~+absorption and transportation in plants.However,there were few reports about Shaker-like family in melon.In this study,in order to enrich the potassium nutrition absorption,transport and salt tolerance mechanism of melon,a Shaker-like outward K~+channel gene(CmSKOR,GenBank accession number MF447462)was isolated from the melon,and it was investigated bybioinformatics analysis,gene mapping,space-time expression and genetic transformation analysis.the main results obtained are as follows:(1)A screening method for high-potassium-efficiency genotype in seedling stage was established initially.(2)Phylogenetic analysis showed that CmSKOR belongs to the SKOR-subfamily in the Shaker-like K~+channel family.Study on transient expression of tobacco(Nicotiana tabacum L.)has shown that CmSKOR was located in the plasma membrane.Transcript analysis CmSKOR is mainly expressed in the roots of melon,and with lower expression levels in stem and leaves.Under potassium starvation conditions,supplementing external K~+could up-regulate the expression of CmSKOR in melon.Salt stress also increased the transcript level of CmSKOR.(3)Overexpressed CmSKOR in wild type(WT)Arabidopsis thaliana can improve the salt tolerance of plants and maintain K~+homeostasis.The transgenic plants showed longer roots,higher maximum photochemical efficiency of PSII(Fv/Fm),much more accumulation of K~+and higher K~+/Na~+ratio than the WT Arabidopsis thaliana under salt treatment.(4)Under salt stress,CmSKOR plays important role on mediating K~+redistribution in melon plants.