Premium
Trichoderma sp. endochitinase and β‐1,3‐glucanase impede Rhizoctonia solani growth independently, and their combined use does not enhance impediment
Author(s) -
Kaur Ramanjeet,
Kalia Anu,
Lore Jagjeet S.,
Kaur Ajinder,
Yadav Inderjit,
Sharma Priti,
Sandhu Jagdeep S.
Publication year - 2021
Publication title -
plant pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.928
H-Index - 85
eISSN - 1365-3059
pISSN - 0032-0862
DOI - 10.1111/ppa.13381
Subject(s) - glucanase , rhizoctonia solani , chitin , chitinase , biology , cell wall , microbiology and biotechnology , trichoderma reesei , hypha , trichoderma , glucan , polysaccharide , biochemistry , enzyme , botany , cellulase , chitosan
Rhizoctonia solani causing rice sheath blight is responsible for significant crop yield losses. Trichoderma spp., biological control agents, have been reported to antagonize R . solani through coordinated action of several cell wall‐degrading enzymes including endochitinase and β‐1,3‐glucanase. In this study two antifungal genes, encoding endochitinase and β‐1,3‐glucanase, isolated from Trichoderma sp. antagonistic to R . solani , were cloned individually in His‐tagged expression vectors and mobilized in Escherichia coli for protein expression. The purified proteins assayed in vitro with R . solani impeded pathogen growth independently by causing hyphal distortions revealed through scanning electron microscopy. The combined use of endochitinase and β‐1,3‐glucanase did not enhance the inhibition. The distortions caused by endochitinase were due to catalytic activity of Glu172 and Asp241 residues on glycosidic linkages in chitin polymers, whereas Glu628, Tyr631, and Asp569 in β‐1,3‐glucanase targeted glucan polymers. The distinctions of this study from earlier reports are (a) chitin polymers in the R . solani cell wall are exposed and not embedded within the β‐glucan matrix; (b) chitin and β‐1,3‐glucan are vital polymers in the R . solani cell wall, rather than chitin as the only main polymer; and (c) hyphal tips of R . solani remain unaffected after an antifungal assay with endochitinase and β‐1,3‐glucanase, instead of exhibiting distortion.