Genetic Transformation And Function Verification Of Arabidopsis AtMYB44and LWT1Genes In Rice

Rice is the staple food of the one third of the world’s population. Abiotic stressessuch as drought stress, salinity stress, high temperature and overoxidation affectsplant growth and development, resulting in crop production. Dwindling arable landand the expansion of the population pose a threat to world food security. Therefore,increase the rice yield, improve the rice quality relate to human survival anddevelopment.Plants to abiotic stresses have been a main goal in agriculture for a long time.Cultivating the resistance rice varieties will have a major impact to the global foodproduction. In recent years, an array of stress-related genes has already beentransferred to rice to improve its resistance against abiotic stresses. The transgenicapproach offers an attractive alternative to conventional production for the geneticimprovement of rice cultivars. Currently one of the most widely applied ricetransformation technologies is Agrobacterium mediated transformation. Thisexperiment discussed in the Agrobacterium-mediated genetic transformation of stressresistance genes into rice, and target gene expression under abiotic stress. Thefindings are as follows:First, the immature embryos of Oryza sativa L. were used for the study onoptimization of Agrobacterium-mediated transformation. Using this method, theMYB44and LWT1genes were introduced into rice, and many transgenic plants wereobtained. Most of the transgenic rice plants were confirmed by PCR technique,indicating the target gene had been integrated into the genome of transgenic riceplants. It was found that adding filter paper on co-culture medium is in favor ofsubsequent sterilization and could improve the conversion efficiency.Second, effects of environmental stresses, including cold, high salt, drought andABA on the expression of MYB44gene were analysised by RT-PCR. The gene wasaffected by all environmental stresses. The result of RT-PCR analysis for transgenicplants undergone various treatments indicated that MYB44, mRNA of gene, wasinduced effectively by drought and Nacl. Overexpression of MYB44enhanced thetolerance against low-temperature stress in rice. And we have obtained transgenicplants. Compared with non-transgenic plants, most of the transgenic positive plantsare able to tolerate drought and salt stress.Third, effects of environmental stresses, including cold, high salt and drought onthe expression of LWT1gene were analysised by RT-PCR. The gene was affected byall cold and drought stresses while was unaffected by high salt. The result of RT-PCRanalysis for transgenic plants undergone various treatments indicated that LWT1mRNA of gene, was induced effectively by drought. Overexpression of LWT1enhanced the tolerance against drought stress in rice. And we have obtainedtransgenic plants. These transgenic lines had stronger tolerance to the drought stressthan the wild plants.