Expression And Function Analysis Of Chenopodium Amaranticolor NDR1 Gene In Transgenic Rice

NDR1(non-race-specific disease resistance 1), a broad spectrum of resistance gene, play an important role in plant defense responses. In our previous studies, two NDR1 homologous genes were cloned from Chenopodium amaranticolor, a broad-spectrum anti-viral plant, and named Ca NDR1 a and Ca NDR1 b respectively. On the basis of these genes which showed a certain resistance to plant virusesin transgenic tobacco, we use Agrobacterium-mediated genetic transformation techniques to generate many transgenic rice lines and followed by greenhouse and field identification of bacterial disease resistance to Bacterial Blight., The results are summarized as follows:1) Plant expression vector were constructed which included Ca NDR1 a and Ca NDR1 b, and were transformed into rice by Agrobacterium-mediated genetic transformation techniques, PCR and southern blot analysis demonstrated that the Ca NDR1 a and Ca NDR1 b genes have been integrated into the rice genome.2) To determine the appropriate bacterial leaf blight pathogen inoculation concentration, we set up the bacterial leaf blight pathogen inoculation concentration gradient to carry on the preliminary experiment. Planting T0 generation of rice, and collecting the seeds and again to obtain T1 generation. Randomly selected part of T1 generation of transgenic rice to carry out the experiments of resistance identification, recording the length of disease spot about three days,five days, ten days after inoculation, and sort out the lines which have better resistance to repeat experiments. The results indicate that the transgenic expression of Ca NDR1 a and Ca NDR1 b render resistant to bacterial leaf blight pathogen and delay the onset.3) Through real-time PCR, we obtained the Ca NDR1 gene expression data in the selected transgenic rice plants. Combined with the resistance identification result analysis data, we found that the expression of exogenous genes in transgenic rice plants is significantly higher than that of control. The highest expression of Ca NDR1 gene in one transgenic line was not showed the good results of disease resistance.4) Planting some lines of transgenic rice and Nipponbare, their agronomic traits were recorded in different rice stages. Results showed that compared with control group the majority of transgenic plants have significant difference on plant height, become shorter. But there are no significant differences on seed setting rate and thousand seed weight related aspects. From that we can filter out the valuable transgenic rice plants which have not only good resistance to disease, but also good agronomic traits and adaptive performance.