Functional Analysis Of Common Bean Gene PvGF14a/g Under Salt Stress

Common bean(Phaseoleae vulgaris L.)is one of the most important edible legumes in the world,which has high nutritional and edible value.Soil salinization is the most serious environmental factor limiting the production of common bean.Therefore,it is significant to study the anti-salt mechanism of it,explore and utilize the genes involved in salt tolerance.14-3-3s are a class of conservative protein family commonly found in eukaryotes that play an important role in response to abiotic stress.The SOS2 gene is an important part of the Salt overly Sensitive(SOS)pathway and plays a key role in the signal transduction of salt stress.Studies in Arabidopsis thaliana showed that 14-3-3 proteins were involved in regulating the adaptability of Arabidopsis thaliana to salt stress by interacting with SOS2 gene,but there were few reports in common bean.The aim of this study was to study the functions of two common bean 14-3-3 protein genes,PvGF14 a and PvGF14 g,for their functions under salt stress.The main results of this study are listed as follows:1.We have analyzed the promoter of PvGF14 g gene and found that the cis-acting elements involved in abiotic stress response were included in its promoter region.Through the GUS chemical staining analysis of tissues of PvGF14a/gpro::gus transgenic plants,it was found that the gus reporter gene expressed in all tissues of Arabidopsis thaliana,but it was not expressed in seeds.We hypothesized that the two genes play an important role in plant growth stage and environmental stress,but may not directly participate in the regulation of seeds.In addition,the GUS staining of PvGF14 a transgenic pod was deeper than that of PvGF14 g,indicating that PvGF14 a and PvGF14 g had tissue expressed specificity.2.We have analyzed the phenotypes of 35spro::PvGF14a/g transgenic plants under salt stress,found that the transgenic plants were more sensitive to salt stress than the wide type: the germination rate of transgenic seed was lower than that of wild type under salt stress,what's more,salt stress treatment made greater inhibition on transgenic seedlings in growth than the wild type,but the total chlorophyll content was no significant difference between transgenic plants and wild type after salt stresstreatment in soil.The results indicated that PvGF14 a and PvGF14 g have negative regulating function in salt stress in seed germination and early growth stage of seedling.3.PvSOS2 is the homologous gene of Arabidopsis ATSOS2 in Common bean,the gene expression of PvSOS2 significantly decreased under salt stress.We have obtained yeast expression vectors and bimolecular fluorescence expression vectors which fused with PvGF14 a,PvGF14g or PvSOS2 gene.The yeast two-hybrid experiment showed that PvGF14 g and PvSOS2 could have interact with each other,while PvGF14 a and PvSOS2 could not.The bimolecular fluorescence complementation experiment showed that PvGF14 a and PvGF14 g in tobacco plants were able to interact with PvSOS2,but compared to PvGF14 a,PvGF14g have stronger interaction with PvSOS2.These indicated the specificity between the two14-3-3 isoforms.All these results provide a theoretical basis for revealing the anti-salt mechanism of common bean and further cultivating the salt-tolerant varieties of it.