Systematic Screening Of Transcription Factors Of Rhizoctonia Solani AG1 IA

Sheath blight of maize is an economically important maize disease that caused serious economic losses in China. Rhizoctonia solani is a pathogen of Maize Sheath blight, which pathogenicity and viability make disease prevention to be a big problem in agricultural production. Regulation of gene expression play the key role in organism, and the regulation at transcriptional level is the most important step in gene expression. Therefore, to explore the transcriptional level regulation mechanisms of R.solani has significant impact on prevention of sheath blight of maize. Transcription factors play important roles in transcriptional level regulation, and involved in the regulation of transcriptional efficiency of gene and enhanced/suppress the gene expression. During infection, many transcription factors of R.solani play important roles, such as enhanced pathogenicity and destroyed host defence. As a result, our reseach on transcription factor of R.solani creates some entry points that to understand the proliferation, response to stress, transcriptional regulation mechanism during the infection of R.solani in depth, not only provided useful referencee, but also has great application value in the field of agricultural disease prevention and treatment.Our experiment focused on the study of transcription factor of R.solani, by constructing the c DNA library of R.solani and using self-activation of yeast-two-hybrid, screened 71 self-activation c DNA sequences with transcription-activation function, and vetifies 41 of them are transcription factors. This method combines the traditional experiments and database analysis, verifies the transcription-activation function of transcription factors with efficient and accurate, and has important significance to elucidate the cell cycle of sheath blight of maize.We aligned 71 self-activation c DNA sequences in Blastx of NCBI and researched protein sequence of each c DNA sequence. After alignment, the homologous protein were 55, and it is about 77.5% of the total sequences; hypothetical proteins were 16. By aligning in the transcription factor database, 41 self-activation c DNA sequence were matched identified transcription factor, 30 of the rest were not matched identified transcription factor. These identified transcription factor classified into 13 transcription factor families, such as Zn2Cys6, Winged helix repressor DNA-binding, HMG, and functioned in proliferation, infection and resistance to drug. As to unidentified transcription factors, because we already have demonstrated transcription-activation function of these 71 proteins in experimental method, and that the data resources of transcription factor database were not the latest, many new transcription factor were not illustrated and classified. So, we can initially determine which 30 unidentified sequences are potential or newly discovered transcription factors. Finally, all of 71 self-activation sequences were analyzed in SMART for conserved domain analysis. Through analysis, 41 identified transcription factors can be detected certain domain, most of which are common transcription factor domain; but 10 of 30 unidentified self-activation sequences did not detect the identified domain, which may be the cause of partial self-activation sequence has not been identified in the transcription factor database. Therefore, the absence in database further illustrated that our library self-activation screening method can not only accurately verify the known transcription factor in c DNA library of R.solani, also screen new and potential transcription factors to fill the blank of transcription factor database. In conclusion, our experimental results have great contribution to follow-up research on function and regulation of transcription factor and explore for proliferation and pathogenic mechanism of R.solani.