Effects Of Viruses Infection On Photosynthesis And Antioxidases And Production Of Transgenic Plants Expressing Coat Protein Genes Of Tumv And CMV In Mustard

Mustard (Brassica juncea var.foliosa cv.Wenzhou) is a very important vegetable which is widely cultivated for a long history in Wenzhou, China. It contributes greatly to the supply of vegetable in both Chinese and abroad markets. However, as the rising of cropping index and perennial cultivation, and using of traditional methods for disease control, viral diseases occur seriously in mustard in recent years, causing severe yield losses, and quality deterioration. Nowadays, it has been a serious problem in the production of mustard. The main plant viruses that infect mustard are turnip mosaic virus (TuMV) and cucumber mosaic virus (CMV), especially TuMV. In this research, the physiological effects of TuMV and CMV infection on photosynthesis and antioxidases of mustard were investigated.The mustard was transformed with genes of TuMV CP and CMV CP mediated by Agrobacterium tumefaciens, this would contribute to breeding strategies of obtaining virus resistant plants.The photosynthetic efficiency of mustard plants after infection by TuMV or CMV was investigated. Compared with control plants, the net photosynthetic rate (Pn) and intercellular CO₂ concentration (Ci) of both TuMV and CMV infected plants reduced. Light saturation points (LSP) reduced, and light compensation points (LCP) slightly increased in infected plants. Compared with CMV infected plants, the changes in above indexes in TuMV infected plants were even larger. The chlorophyll fluorescence parameters were also detected in mustard leaves at different stages after infected by TuMV and CMV respectively. The results showd similar trends of changes in chorophyll fluorescence parameters in plants after TuMV and CMV infection, and...