Proteomic Study of Biocontrol Mechanisms of Trichoderma harzianum ETS 323 in Response to Rhizoctonia solani

摘要

To elucidate the entire range of proteins that are secreted by Trichoderma harzianum ETS 323 in its antagonism with Rhizoctonia solani, an in vivo interaction between them was mimicked and not only the secreted cell wall-degrading enzymes (CWDEs) but also all of the proteome were investigated. Seven CWDEs, chitinase, cellulase, xylanase, β-1,3-glucanase, β-1,6-glucanase, mannanase, and protease,were revealed by activity assay, in-gel activity stain, 2-DE, and LC-MS/MS analysis. Extracellular protein extracts from media that contained ft solani exhibited much higher CWDE activities than media that did not contain ft solani. Cellulase and mannanase activity, however, were insignificant. Activity stain also revealed that β-1,3-glucanase, β-1 ,6-glucanase, and xylanase activity occurred exclusively in media that contained ft solani. Furthermore, 35 of the 43 excised spots on the 2-DE gel were successfully analyzed by LC-MS/MS, and eight proteins were identified. They were two glycoside hydrolases, two proteases, two β-glucosidases, one endochitinase and, interestingly, one amino acid oxidase. Additionally, a possible mechanism was proposed to elucidate how the cell walls of ft solani are systematically enveloped and disintegrated.