Screening And Functional Analysis On Salt-tolerance Genes Of Sophora Alopecuroides L

Soil salinization is a global problem of restricting agricultural production, it was estimated about 20% of global arable land threatened by salt injury, 43% of the cultivated land in arid and semiarid area. Salt damage seriously affect plant growth and development, responsible for the crop production, and the deterioration of ecological environment. Due to the growth of crop seriously affected by environmental stresses, its genetic potential is hard to play under natural conditions, salt-damage not only affect the yield of crops, and limits the widely distributed in plants, thus, enhancing the ability of salt tolerance has become one of vital research work needed to resolve for resistant breeding. With the development of molecular biology, and mature transgenic technology, using transgenic technology to improve plant salt-tolerance has become an effective way to improve saline-alkali soil.At the same time, xerophytic, salt-tolerant plants was used as research materials for separating and cloning the remarkable salt-tolerantgene that is an effective method to obtain resistance gene resource.Sophora alopecuroides is the leguminous plants of the genus robinia, alias manufacture, and plants of perennial herbs, roots underground bud, xerophytic and salt-tolerant. For significant drought and salt resistance, it is an abundant genetic resources of resistant gene. In this study, salt-tolerance relevant genes was screened from c DNA yeast expression library of sophora alopecuroides, and two salt-tolerance genes was screened,named Sa IMT and Sa AQP, preliminary analysis was conducted for its structure and function at the same time, in order to further validate the salt-tolerance gene, in which lay a theoretical and technical basis for resistant breeding. The main research results are as follows:1The roots of sophora alopecuroides was used as experiment material under Na Cl salt stress, full length c DNA library was build using the method of SMART, the total number of cloning of yeast was 2.3 x 107 cfu get from c DNA expression library, library drops to 7.7 x 106 cfu/ml, insert fragment length was between 1.2 KB of 2.0 KB, related parameters were in conforimty with the quality standards for expression library.2 Yeast plant screening system was used for screening seedling root of sophora alopecuroides c DNA expression library, a total screening of 16 salt-tolerant clones, and followed gene sequencing and sequence alignment, finally got salt-resistant genes, respectively is Sa IMT alopecuroides methyltransferase gene and inositol Sa AQP water channel protein gene of sophora alopecuroides. Open reading frame was of 1095 bp, Sa IMT encode 364 amino acids;Open reading frame was of 753 bp, Sa AQP genes encoding 250 amino acids.3. Bioinformatics analysis was implemented for Sa IMT and Sa AQP, it was found that Sa IMT and Sa AQP has high homology and close genetic relationship with other species’ IMTs and AQPs, at the same time Sa IMT and soybean Gm IMT, Sa AQP and arabidopsis thaliana At AQP were correlated protein with high conservative sequence and structure, and protein tertiary structure are very similar, thus both of Sa IMT and Sa AQP and its homologous genes hold similar functions.4 Sa IMT and Sa AQP gene expression were analyzed in different tissue of sophora alopecuroides, and found that gene expression quantities of Sa IMT and Sa AQP in the root were significantly higher than that of leaf and stem; Na Cl salt stress was carried out on the seedlings of sophora alopecuroides, gene expression of Sa IMTand Sa AQP were increased obviously in the preliminary stress.5 Sa IMT and Sa AQP were transformed into hair root agrobacterium K599 using leguminous model transformation system and induced hair roots were infected, followed Na Cl salt stress on genetically modified soybean hair root and complex of transgenic soybeans and hair root, finally identification on salt-resistance of Sa IMT and Sa AQP were get.As results shown that salt-tolerance were improved obviously on soybean hair root and complex of transgenic soybean and hair root with gene of Sa IMTand Sa AQ, therefore Sa IMT and Sa AQP could improve salt- tolerance of transgenic soybeans.