Cloning And Preliminary Studying On The Function Of Root-Specific Expression Gene GmRLK1in Soybean

Soybean (Glycine max) is one of the world’s major grain and oil crops, it is one of the most important resource of plant protein for human beings.Root is a long-term adaptation of life on land and gradual formated of organs in the course of evolution,which constitute underground part of the plant, root’s main role is fixed the plant body, and absorb water and inorganic salt from the soil, provides nutrients necessary for growth on the ground. Some adverse natural conditions, such as drought, waterlogging, salt damage and so on have close relationship with plant roots, and the roots have nitrogen-fixing effect of soybean, root-specific gene expression study not only has a great value in use on plant growth and adversity in soybean genetic engineering breeding,but also provide more various theories for gene engineering of Insect resistant plant development, nitrogen fixation, etc.The main content of this study:(1) Through bioinformatic method and datamining, alfalfa Srlk gene sequence encodes receptor-like protein kinas as a seed sequence to blast soybean genome database, searching high homology gene fragments, named GmRLK1. Studies have established that Srlk gene is associated with adverse environment. Comparison of the fragment sequence with that of GmRLK1and Srlk gene was carried out through blast in GenBank,the result showed that the homologies of the nucleotide sequence was80.8%with GmRLK1. The structure of GmRLK1sequence and its putative coding protein was analyzed. The results showed that GmRLKl possesed the character of receptor-like protein kinase, Futhermore it showed that it contain the character of receptor-like protein kinase with leucine rich repeats. The tissue organ-specific expression pattern of the GmRLKl showed that its transcripts were detected weakly in leaves and stems, and abundantly in roots.The research construct of RNAi expression vector containing LRR-RLK like gene GmRLKl.(2) Seeds were cultivated in the medium, after5-7days, took that seedlings as explants. Seedlings were cut into4different parts:seed leaf,hypocotyl, cotyledonary node, cotyledon as explants to analysis the effect of different plants on hairy root induction. The best condition of inducing soybean:basic culture medium MS; pre-culture time2days; Agrobacterium rhiaogenes K599, AS100μM/L, cotyledonary node; highest inducing rate92.50%.(3) The GmRLK1gene has been successfully conformed to the transgenic soybean after Spec screening, PCR identification. Obtained transformation of soybean root through screening can further validation of this gene in adversity conditions. Analysis of salt tolerance in transgenic soybean hairy root with GmRLK1gene. analysis of salt tolerence of transgenic hairy roots showed that the length increments of in vito transgenic hairy roots on solid culture meidum were superior to that of the non-transgenic under salt100mmol/L NaCl stress. It is proved preliminarily that GmRLKl gene may be related to salt stress.