Drought-related Genes On Maize And Arabidopsis Transformation

Drought usually company with strong light, which result to osmotic stress and oxidative stress to plants. Under the water-stress, betaine has an important role in regulating the osmotic balance of the plant. So transformation of badh which is one of the key enzymes in the the synthesis of betaine into plant should improve the plant's drought-resistance. Catalase (CAT )is regarded as a key enzyme in the anti-oxidation system of the plant. CAT mainly locates in the peroxisome, not the chloroplast. But the chloroplast is the main position producing reactive oxidative species (ROS). So transformation of CAT into chloroplast is important strategy to improve the plant's drought-resistance ability.In this experiment, we construction the vector p3301-121-bc which have the tr-cat and badh. So the CAT can function in the chloroplast. The vector was transferred the vector into the Maize and Arabidopsis thaliana and mediated by the Agrobacterium tumifaciens. Maize transformants were selected on the medium containing phosphinothricin (20mg/L), 25 trans-cat,badh lines were alive and Arabidopsis thaliana transformants were selected by spraying phosphinothricin (500ml/L) 10 trans-cat,badh lines were alive.The cat and badh gene had been intergrated into Maize and Arabidopsis thaliana genome which confirmed by PCR for Maize and by PCR, RT-PCR, Western blot for Arabidopsis thaliana. Western blot results indicate that gene had expressed in the Arabidopsis thaliana normally. When the plants were subjected to 20% (w/v) PEG-6000, then some indexes were determined between the non-transgenic plants and the transgenic plants. The results showed that the degrees of plasma injury,reduction of chlorophyll and PSⅡinjury were all lower in the transgenic plants It is indicate that transgenic plantswere have stronger ability of osmotic regulation. In conclusion, the transgenic Arabidopsis thaliana showed improved tolerance to osmotic stress by over expression of CAT. The transformed Maize set the found of heredity breeding. The transformed Arabidopsis thaliana can be further studied in the physiological metabolism of stress resistance.