Expression Analysis Of Rice Difference Genes Induced By Rhizoctonia Solani

Rice sheath blight is one of the three worldwide major diseases witch will cause severe loss in yield and quality under favorable environmental conditions. Although there were not completely immune or highly resistant varieties, the difference of resistance is very great among varieties. Therefore, it is very necessary to elucidate the molecular mechanism of interaction between rice and Rhizoctonia solani, which could provide further information for resistance breeding of rice and reasonable use of resistant varieties. In the study, suppression subtractive hybridization(SSH) was used to construct cDNA library and global gene expression profile induced by Rhizoctonia solani was , analyzed. The results provided a research foundation to elucidate the interaction mechanism between rice and R.solani.Three methods of extracting tatol RNA from rice leaves were compared in the experiment. The optimum modified Trizol methodâ…¡was established. The result of agarose gel electrophoresis analysis showed that the total RNA obtained by modified Trizol methodâ…¡has three clear bands 28s rRNA,18s rRNA and 5s rRNA. The ratio of OD260/OD280 of total RNA extracted by Trizol methodâ…¡was 1.991. The results indicated that the total RNA extracted by the modified Trizol methodâ…¡had higher purity and was more integrated.Rice cultivar Hejinag19 and Kongyu131 were used in the experiment. The SSH library was constructed with rice seedling inoculated by R.solani. There were 2112 positive clones in two SSH librarys. 50 clones from each library were selected for secquencing. 63 qualified ESTs sequences were obteined. The sequences similarity was analyzed through Blastn and Blastx searching in gene databases, and 61 of the ESTs were identified encoding putative proteins. There are 37 ESTs coding for known function proteins, 24 for unknown proteins, and 2 ESTs were not match with similar sequences in GenBank.The function of these genes involve in photosynthesis, energy metabolism, disease defense and signal transduction. Among the ESTs obtained, the ESTs which involved in photosynthesis were 50.7%.After ESTs analysis, we supposed that PSII 10kDa protein, Rubsico and Fructose-bisphosphate aldolase might participate in the resistance process, and GOX, GPX, MT, ABC transcription factors, WRKY transcription factors 24, ras-related proteins 1 and disease resistance-related protein might might play a role in rice resistance to R.solani.