Interaction between proteinases secreted by the fungal plant pathogen Rhizoctonia solani and natural proteinase inhibitors produced by plants

• Published in: Prikladnaja biohimija i mikrobiologija Vol. 42; no. 5; p. 572
• Main Authors: Gvozdeva, E L, Volotskaia, A V, Sof'in, A V, Kudriavtseva, N N, Revina, T A, Valueva, T A
• Format: Journal Article
• Language: Russian
• Published: Russia (Federation) 01.09.2006
• Subjects: Basidiomycota - chemistry; Basidiomycota - enzymology; Fungal Proteins - chemistry; Fungal Proteins - secretion; Peptide Hydrolases - chemistry; Peptide Hydrolases - secretion; Plant Diseases - microbiology; Plant Proteins - chemistry; Plant Proteins - metabolism; Protease Inhibitors - chemistry; Protease Inhibitors - metabolism; Solanum tuberosum - chemistry; Solanum tuberosum - microbiology
• ISSN: 0555-1099

The fungal plant pathogen Rhizoctonia solani Kuhn. grown in a medium containing thermostable potato tuber proteins produced proteinases active at moderately alkaline pH values. Electrophoretic analysis in polyacrylamide gel with SDS and copolymerized gelatin showed that the extracellular proteinase complex contained four components that differed in molecular weight. Studies on the action of the exoenzymes on various synthetic substrates indicated that the culture liquid of R. solani contained mainly trypsin-like proteinases. The exoproteinase activity was virtually completely suppressed by trypsin inhibitor proteins isolated from potato tubers and seeds of various legume species. The results suggest that the extracellular proteinases produced by R. solani play a significant role in attacking plant tissue, and natural inhibitors contribute to the protection of Solanaceae and Leguminosae from this fungal pathogen.