Functional Analysis And Genetic Transformation Of Chilling Tolerance Gene ZmMAPKKK In Maize

Maize is one of the world’s three major food crops, and is also the most important feed crop, which plays an important role in the world. While China’s maize acreage has surpassed the United States to become the biggest one in the world, but the production is not in the first place. The chilling damage in the Northeast of China is one of the main meteorological disasters affecting maize yield production. Therefore, It is particularly important to cultivate new maize with chilling resistance ability for increasing the production in the northeast.In this study, PCR cloning technology was used to clone the MAPKKK of W9816 from maize material in cold treatment which followed by the bioinformatic analysis. The change of W9816 expression level of maize inbred line MAPKKK under abiotic stress was analyzed by qRT-PCR. We constructed a plant over expression vector pCAMBiA3301-ZmMaPKKK and RNAi vector p3301-35s-MaPKKK (+)-intron-MAPKKK (-).The target gene was transferred into wild type Arabidopsis thaliana, and the molecular detection of T3 transgenic ZmMAPKKK Arabidopsis thaliana was carried out, and the results were positive. Phenotype observation and physiological indexes determination of the transgenic Arabidopsis were further performed. The results show that, the transgenic Arabidopsis growth were better than that of the control under abiotic stress; Under cold treatment, the determination of POD、SOD、 CAT and MDA showed that the transgenic Arabidopsis is more tolerant compared to wild type. The results show that the gene transformation to a certain extent improves the tolerance ability of Arabidopsis thaliana to low temperature and drought stress.Using Agrobacterium mediated method to transfered target gene into maize inbred lines Y423, from which the immature embryos and embryogenic callus are the transformation acceptor material. At last transgenic plants were obtained, and transformation rates were 10.5% and 9.9%. Meanwhile by using the pollen tube path way, the target gene was transformed into maize inbred lines 73,71 and 69.68 transformants were obtained, and the rate of transformation is 1.65%.In short, we coloned a cold related gene ZmMAPKKK from the maize materials W9816 in this study, predicted its structure and function, and detected the changes in the expression of the gene under abiotic stresses. Further more we studied the function of gene ZmMAPKKK and its genetic transformation of gene ZmMAPKKK which provided target gene resources for the selection of maize cold resistant related genes and cultivation of cold resistance of Maize Germplasm.