Functional Analysis Of Wheat LEA? Gene TaDRLea3-2 In Escherichia Coli And Arbidopsis Thaliana

Wheat is one of the most important grains for human beings,but drought is one of the important reasons for the decrease of yield.LEA protein can be expressed abundantly when plants under stress conditions,which can alleviate the damage caused by drought and play a protective function to plants.LEA3 protein is an important member of LEA protein family.Our lab has cloned the Ta DRLea3-2 gene from wheat "Zhengyin No.1".The function of Ta DRLea3-2 protein was evaluated by protection of LDH in vitro and its responding to abiotic stresses.Moreover,the resistance ability of drought stress in transgenic Arabidopsis or Escherichia coli was also evaluated.This study laid a foundation for further understanding of the function and mechanism of LEA protein in resisting abiotic stresses,especially drought stress.The main results are as follows:1.The recombinant vector p ET28a-Ta DRLea3-2 was transformed into Escherichia coli BL21(DE3).The molecular weight of the recombinant protein was near 23 k D detected by SDS-PAGE.The recombinant protein was purified using the Ni2+ resin column and verified by western blotting using His antibody.2.LDH protective assay in vitro showed that Ta DRLea3-2 protein could protect LDH enzymatic activity after freezing and high temperature treatment,respectively.3.Escherichia coli BL21(DE3)overexpressed Ta DRLea3-2 protein and empty vectors was treated with high osmotic,high salt,high temperature and low temperature,respectively.Compared with empty vectors strains,Escherichia coli overexpression of Ta DRLea3-2 protein could enhance the viability of Escherichia coli during stress conditions.Ta DRLea3-2 protein enhanced the abiotic stress resistance of Escherichia coli.4.The plant expression vector of p BI121-Ta DRLea3-2 was transformed into Arabidopsis by agrobacterium-mediated method.The seeds of T3 generation transgenic plants was used for further study.At seedling stage,the root length of transgenic plants was longer than that of wild type plants.After drought treatment,water content,chlorophyll content,MDA content and proline content of transgenic lines were better than the wild type plants.These results suggested that Ta DRLea3-2 protein enhanced the abiotic stress resistance in transgenic plants.