Functional Analysis Of The Maize And Arabidopsis Lip5 Under Salt And Drought Stresses

Abstracts Lip5 protein is a member of Vtal subfamily, plays a role in the lysosomal degradation pathway of intracellular multivesicular bodies (MVB), and plays an important role in plant growth and development,it maybe related to salt and drought stresses. The study of the mechanism of Lip5 proteins in the plant isn’t only extended the Vtal family functions, but also has great significance for breeding. This research has cloned Lip5 gene in Arabidopsis and maize which coding protein ZmLip5 and AtLip5 and then analysised gene sequence and function, my main focused on five aspects as follows:1. Get the Zea mays Lip5 (GB:ACN36293) and Arabidopsis thaliana Lip5 (AT4G26750) cDNA sequence by bioinformatics, Though the sequence alignment and function domain forecast and analysis found that all Lip5s has DUF605 function domain, which has a difference between different species.2. Expression patterns of ZmLip5 and AtLip5 in maize and Arabidopsis.Using real-time quantitative fluorescence PCR (real-time PCR) to do analysis of the expression quantity of ZmLip5 and AtLip5 in corn inbred line Zheng 58 and Arabidopsis(Col 0)which was dealt with 2 stress conditions:drought and salt stress. The results indicated that ZmLip5 and AtLip5 expression quantity have risen under salt and drought stresses; Get ZmLip5 promoter (ZmLip5-P) and AtLip5 promoter (AtLip5-P) sequence by bioinformatics analysis, built promoter:GUS plant expression vector. GUS histochemical staining showed that AtLip5 has different expression level in each growing period of Arabidopsis thaliana.3.Treat ZmLip5 and AtLip5 transgenic yeast with mannitol and salt, found ZmLip5 and AtLip5 transgene yeast reduced high salt, mannitol adaptability, particularly AtLip5 transgenic yeast.4. Do analysis of the Arabidopsis WT and T-DNA insertion mutant atLip5 which was dealt with 3 stress conditions:PEG、ABA and salt stress. The results indicated that T-DNA insertion mutant atLip5 enhanced high salt adaptability. Got AtLip5 overexpression Transgenic Arabidopsis.5. Identified 3 kinds of inbred lines which have shown drought and salt stresses tolerance, and 3 kinds of inbred lines which have shown drought and salt stresses sensetive from 47 maize inbred lines. Using real-time quantitative fluorescence PCR (real-time PCR) to do analysis of the expression quantity of Lip5 in these 6 inbred lines which was dealt with 3 stress conditions:control、drought and salt stress. The results indicated that whatever CK or stress conditions, expression quantity of Lip5 in these 6 inbred lines has shown negative correlation with phenotype; Got ZmLip5 overexpression Transgenic Arabidopsis.All the above results proved that,ZmLip5 and AtLip5 played negative role in plant drought and salt resistance.And there should be more research fouced on molecular and protein levels to reveal the mechanism of Lip5.