| Bacillus spp. is a type of biocontrol bacteria, which is ideal for the biocontrol agent.since it has characteristics like promoting plant growth; inducing resistance; generating heat resistance, salt resistance, ultraviolet resistant endospore. The experiment aimed at screening Bacillus strains of our laboratory which have better control effect of rice bacterial diseases, through laboratory, greenhouse and field experiments.1. It was showed with antagonistic activity on NA plates that, Bacillus strains preserved in our laboratory had good antibacterial effect of rice bacterial blight. Bacillus strain90showed antibacterial circle diameter28mm, the inhibition rate reached60.87%. Bacillus strain G1-harpin showed antibacterial circle diameter24mm, the inhibition rate reached52.17%. The inhibition rate of Bacillus strain38reached60.87%. The experiment of Bacillus on rice plant growth results showed that, shoot lengths and root lengths of rice seedlings were increased obviously after Bacillus treatment. Treatment with Bacillus strain FZB42resulted in greatest beneficial effects on rice growth, as root and shoot lengths increased by40.9%and56.7%, respectively. Bacillus strains90, G1-harpin,38and B3increased shoot lengths by31.5%,16.2%,10.0%and7.1%, respectively, while root lengths were increased by40.6%,26.4%,15.7%and19.1%, respectively. The experiment results of greenhouse and field control of rice bacterial diseases showed, Bacillus strains from our lab also had good control effect of rice bacterial disease under natural conditions, and the optimized formulation of Bacillus strains and chemical bactericide could significantly improve the field control effect. 2. Aimed to get the high-resolution two-dimensional gel electrophoresis system, the method of protein extraction and the experimental conditions were optimized in the present study. The results showed that the quality of rice protein using the optimized TCA-acetone precipitation method was better and the2-DE images were clearer, proteins with defferent isoelectric point and Molecular Weight were separated well. When the protein concentration loading for2-DE was0.4mg/mL, the good protein pattern with protein spots distributing equably and ayllabify could be obtained. The method of many steps wiping off salt and low voltage for isoelectro focusing in IEF process could reduce the cross striation and the good2-DE images were obtained.3. Reports suggest that Bacillus spp. can be used to increase plant growth and resistance to disease, but the molecular mechanisms underlying the interaction between Bacillus spp. and plant is not completely understood. In the present study, to clarify these underlying mechanisms, the interaction between Bacillus spp. and rice was investigated using two-dimensional gel electrophoresis. Through comparative analysis, a total of31differentially expressed proteins were obtained upon Bacillus spp. treatment, including22proteins that were up-regulated and nine that were down-regulated. These data indicated that certain proteins involved in plant growth and development were up-regulated, such as xyloglucan endotransglycosylase. Interestingly, proteins involved in defense were also up-regulated, including peroxidases, glutathione S-transferases and kinases. Thus, proteins associated with disease resistance characteristics were induced in the plants after exposure to Bacillus spp. In addition, several proteins involved in protein-and lipid metabolism showed significant changes in expression. Overall, this present study demonstrates that Bacillus spp. can up-regulate the expression of proteins related to plant growth and defense, and lead to enhanced plant growth and disease resistance.4. Appendix one showed one important part of my research work, tow soybean transformation systems for expression of harpinxooc protein were established. This study aimed to optimize the experimental conditions in the soybean transformation process, establish tow soybean transformation system used soybean embryonic tip, agrobacterium-mediated soybean transformation and biolistic-mediated soybean transformation. The vector pCAMBIA3300::hrf2and agrobacterium strain EHA105(3300::hrf2) were designed for soybean transformation. Following the glufosinate selection, many acclimatized plantlets were obtained. The results of PCR detection for soybean transgenic seedlings showed that transgenic positive plants were obtained using these two soybean transformation systems. The research established the experimental foundation for next work. |
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