Soybean WRKY, Exo70and Related Genes Functions In Growth And Drought Resistance

A large number of studies show that WRKY and VQ interacting proteins play an important role in plant resistance to diseases and stresses, but there is no systematic analysis and research in soybean. In order to extensive and in-depth research about soybean WRKY and VQ proteins in drought resistance function, we analyzed through quantitative PCR system of soybean WRKY and VQ gene expression changes after drought and ABA treatment, we get a batch of soybean WRKY and VQ genes response to drought and ABA, and choose three genes, VQ34VQ58and WRKY56for further analysis of the function. Yeast two hybrid showed that soybean VQ34and VQ58interaction with two WRKY family members, and that they may be play a role in the plant by affected WRKY transcription factor. Amino acid sequence analysis found that soybean WRKY56and Arabidopsis WRKY51highly homologous in their sequence, in the highly conserved WRKY functional domains are common amino acid variation, In order to study the two WRKY gene function directly, we have obtained Arabidopsis overexpression transgenic plants through agrobacterium-mediated transformation technology, at the same time, we preliminary analysis their drought resistance. We also received a small amount of over-expression of soybean transgenic plants, laid the foundation for the further research in the future.Many genes change function by mutation or other changes, prompting the biological evolution. In the process of analyzing the soybean WRKY family, we found that one of the members not only contain a variable WRKY function domain, also has a specific transmembrane (TM) domain. The novel WRKY related protein (GmWRPl), which contains a WRKY domain with no binding activity for W-box sequences, through the green fluorescent protein (GFP) fusion revealed that GmWRP1was apparatus not in the nucleus. System analysis the protein of the soybean and other plant, found that the transmembrane domain also binding some exocytosis complex Exo70protein subunits, thus forming a leguminous plant unique Exo70family. Fluorescence microscopic observation found that these Exo70protein also target to the Golgi apparatus. GmWRP1transcripts were detected at high levels in roots, flowers, pods and seeds and were elevated with increased age in leaves. Silencing of GmWRPl and some GmEx070J genes resulted in reduced nodule formation and accelerated leaf senescence in soybean. And their expression in Arabidopsis thaliana altered leaf and flower growth. Thus the legume-specific, Golgi apparatus-localized GmWRPl and GmExo70J proteins play important roles in legume growth and development potentially through involvement in vesicle trafficking of proteins and nutrients.