Preliminary Study Of Soluble Proteins In Potato Tuber Slices Induced With Actinomyces A5295 Against Late Blight

Potato (Solanum tuberosum L.) is annual herbaceous plants in Solanum, and its planting area and output rank fourth in the world. It is a very important food and vegetable crop. China is the world’s largest production base of potato. Potato late blight is the most serious disease threatened potato production; its occurrence can cause serious cuts and even absolutely production. With the development of agricultural technology, awareness of environmental issues and food safety concerns, use of plant induced resistance to control crop diseases has become hotter at home and abroad. In recent years it has been reported upon in various biological sources and non-biotic elicitors of induced resistance against Phytophthora infestans. But its mechanism of induced resistance is relatively few.This paper is based on our laboratory’s early research of microbial elicitors inducing potato against late blight. It is clear that actinomycetes A5295 strain separated and stored up in our aboratory which had evident induction effect for enhancing resistance in potato against late blight. Here, optimal fermentation time, change of soluble proteins and resistance related enzymes in potato tubers after induced treatment were investigated in this experiment. The results can provide the theoretical basis for further understand mechanism of induced resistance in potato to late blight. It is also important for revealing the mechanism of other types of elicitor induceing potato resistance against late blight and other fungal diseases.The main results of this experiment are as follows:1. Broth dry matter content in fermentation of different seed culture time and fermentation time combination of actinomycetes A5295 were compared and optimized. Using fermentation liquid for 7d seeds liquid combination with expending fermentation 16d could obtain the best dry matter and its induction efficance reached 50.28%.2. Induction effect of using fermentation liquid on different resistant varieties potato of the Atlantic and Bashu 4 was compared, and the result showed that there were no big differences beween them. The induction effect of A5295 fermentation liquid will not be influenced by potato varieties. 3. Soluble protein changes in potato tubers after elicitor induction and challenge inoculation were analyzed. The bands of soluble proteins were increased in all induced by different elicitor. Soluble proteins bands increased also in that after challenging inoculation, and changes was focused on between 20~40KD and 50~80KD. It indicated that type and content change of soluble proteins might be related to potato resistance to late blight process.4. Activity changes of disease resistance-related enzymes (PPO, POD, PAL, SOD) in potato tuber slices were measured after elicitor induction and challenging inoculation. Activitys of four enzymes were higher under one fold concentration of elicitor induced than 2 fold ones. But after the challenge inoculation, three enzyme activitys (PPO, PAL, SOD) of 2 fold elicitor induction were higher than that of 1 fold except POD, it might activate the different mechanism of induced resistance.