Isolation And Functional Analysis Of Stress-responsive Genes GmEF13,GmAPK1 And TaSRP

Drought and salt are two major constraints to yield and quality of wheat and soybean in our country.Abiotic stress such as drought and salt affect crop growth seriously in our country.How to improve drought and salt tolerance of crops has became an important objective of breeding.Plants have evolved the capacity to respond to wide range of stresses.It is important to analyze the molecular character of genes that involved in abiotic stressess and its signal transduction and responsive mechnism in resistance to stresses.In order to study the signal transduction mechanism mediated by GmPK12 protein kinase,yeast two-hybrid analysis,BiFC and pull-down assay of GmPK12 and its interaction protein,GmEF13 and GmAPK1 were made in this research.We also have obtained a ricin B-linke lection gene,TaSRP,which belongs to EUL family,by searching the results of salt treatment wheat de novo transcriptome assembly,containing a EUL domain,belongs to EUL family.The main details of the result as follows:1.Promoter regions in GmEF13 contained variable numbers of stress-responsive cis-elements.GmEF13 was highly expressed during drought and heat treatment.T-DNA insertion mutant atef13 in Arabidopsis exhibited hypersensitivity to PEG and heat treatment that was rescued in transgenic lines overexpressing GmEF13.GmEF13 protein localized uniformly throughout the Arabidopsis protoplast and interacted with GmPK12.overexpressing GmEF13 lines improves drought tolerance in Arabidopsis.2.GmAPK1 localizes on the plasma membrane and possesses autophosphorylation activity.The interaction of GmAPKl and GmPK12 suggests that GmAPK1 might be involved in the brassinosteroids(BRs)signaling pathways.RT-PCR analysis revealed that the expression of GmAPK1 was upregulated by BR,but downregulated by drought and salt treatment.Overexpressing GmAPK1 in Arabidopsis makes the plant sensitive to drought.3.The subcellular localization assay indicated that TaSRP located in cytoplasm.RT-PCR analysis revealed that the expression of TaSRP was upregulated by ABA and salt.Isolation of the TaSRP promoter revealed a core promoter element and some cis-acting elements responding to abiotic stresses.The total root lengths of three TaSRP lines were significantly longer than those of wild-type plants under salt treatment in Arabidopsis plants.These results indicated that TaSRP lines improve salt tolerance in Arabidopsis.