Cloning And Functional Analysis Of OsSTSL1in Rice

Rice (Oryza sativa L.) is one of the world’s most important crops and raises about40%of the population all over the world. Rice owns the largest planting area and the highest yield and total output in China, which plays an important role in grain production and more than60%of the population in our country eat rice as the staple food. But the increasingly highlight adverse factors such as a sharp drop of land resources, salinization of lands, decreace of water resources and drought pose a serious threat to rice production. Plants cope with adversity stress mainly through regulating the expssion of genes and causing a series of signal transduction pathways which result in a series of physiological and biochemical reactions in order to reduce the damage caused by adversity stress. The effective ways to improve the rice yield are to research rice gene and the mechanism about stress resistance and take molecular genetic improvement for improving adaptability to the adversity stress of rice.Adversity stress such as salt stress, drought and so on and plant hormones such as abscisic acid(ABA) are all the important factors that affecting rice production, so studying the adversity stress response genes in rice and its mechanism is very necessary. Based on STS1(Sensitive To Salt1)of Li Xia teacher’s group and through bioinformatical and homology cloning methods, this study find a gene which responses to the ABA, NaCl and PEG (drought simulation), named as OsSTSL1, and we clone it and study its function by homologous and heterologous transformation. OsSTSL1protein is found that it contains seven WD40domains by bioinformatic analysis, and belongs to the member of the WD40protein families; the promoter sequence analysis founds that OsSTSL1promoter contains a DRE, two ABRE, six MYC and a MYB cis-acting elements. Real-time PCR test reveals the expression of OsSTSL1is induced by ABA and NaCl, and has a highest expression after three hours treatment, then gradual decline; But under the condition of PEG treatment, the expression of OsSTSL1shows a trend of decline. GUS staining analysis shows OsSTSLl expresses in leaf, leaf vein, hypocotyl and root, and the ABA induced expression is not obvious. GFP subcellular localization shows OsSTSL1protein expresses in the nucleus and cytoplasm. Overexpression lines of OsSTSL1in Arabidopsis can tolerate NaCl stress and ABA compared with Col-0at greening stage, but sensitive to drought stress; there is no much difference of main root length between Overexpression lines of OsSTSLl of Arabidopsis and Col-0when they vertical growth under ABA and NaCl stress. BiFC experimental result shows that the OsSTSL1protein interact with OsABI2protein, which further confirms OsSTSL1may be involved in rice response to adversity stress.In this paper, the researches of OsSTSL1reveal the molecular mechanism in rice under ABA, NaCl, and drought stress with new scientific basis, which provides the theory basis and genetic resources for molecular breeding and the rice genetic improvement.