Study The Bacteriostatic Action Comparative Genomics And Proteomics In Trichoderma Hamatum

Trichoderma was one of the most potential biocontrol strains in fungi. In this paper, T. hamatum was assessed as the research focus. By means of comparative genomics and proteomics, differential expression of related genes and proteins were analyzed as to reveal the mechanism of bacteriostatic activities produced by T. hamatum. In addition, the differential expression of genes were eventually validated with qRT-PCR. The main results were as follows:1. The pathogen Ralstonia solanacearum, biocontrol strain (YYH13) as well as non-biocontrol sratin(YYH16) were isolated from the soil in the pathogenic areas. The metabolite and fermentation liquor of YYH13 showed obvious bacteriostatic activities to R. solanacearum. Below 80℃, the fermentation liquor could keep the restraining activities. After 120h’s fermentation, the fermentation liquor had the best restraining activities. In the field experiments, the fermentation liquor showed well restraining activities to R.solanacearum.2. The secretome of YYH13 can be well extracted with 50% saturation (NH4)2SO4 The molecular weights range of YYH13 differential secreted proteins were about 80-100 kDa,40-50 kDa and 20-30 kDa. By means of SDS-PAGE and LC-MS/MS method,125 effective differential proteins were identified. Eight protein fragments were analyzed as the emphasis in Mascot database. Among them, the amino acid residue IVLGMPIYGR had 100% homology with endochitinase.3. The whole genome sequencing, splicing and assembling of YYH13 and YYH16 were conducted. The results showed that they were 43.29M and 49.83M respectively. The functions 11316 and 11087 genes, as well as 6648 and 6110 GO classification were forecasted. Comparative analysis of expansion and contraction of gene family between the species of Trichoderma atroviride, Trichoderma harzianum, Trichoderma reesei, Trichoderma viren. YYH13 and YYH16 were conducted 78 gene families which were related with bacteriostatic activities were obtained. The evolutionary relationships of 13 gene families were analyzed. The relationship and difference between the two whole genomes were analyzed, and the foundations as well as their metabolic processes and specific gene interaction networks were forecasted.3 gene families were found to play the key role in the biocontrol of R. solanacearum.4. Based on the results of comparative genomics and proteomics, the YYH13107 (endochitinase gene), YYH132757 (exo-1,3-beta-glucanase gene) and YYH1311002 (MAPK gene) in YYH13 and YYH16 were analyzed with qRT-PCR. The chitinase gene chit18-18 was cloned, its sequence and structure characteristics were analyzed and predicted.