Trichoderma harzianum ETS 323-Mediated Resistance in Brassica oleracea var. capitata to Rhizoctonia solani Involves the Novel Expression of a Glutathione S‑Transferase and a Deoxycytidine Deaminase

• Published in: Journal of agricultural and food chemistry Vol. 60; no. 43; pp. 10723 - 10732
• Main Authors: Shibu, Marthandam Asokan, Lin, Hong-Shin, Yang, Hsueh-Hui, Peng, Kou-Cheng
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 31.10.2012
• Subjects: apoptosis; Biological and medical sciences; biological control agents; Brassica - enzymology; Brassica - genetics; Brassica - immunology; Brassica - microbiology; Brassica oleracea var. capitata; complementary DNA; Cytidine Deaminase; cytotoxicity; DNA adducts; Food industries; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation, Plant; glutathione transferase; Glutathione Transferase - genetics; Glutathione Transferase - immunology; hydroponics; Hypocrea lixii; leaves; lipoxygenase; neutralization; Nucleoside Deaminases - genetics; Nucleoside Deaminases - immunology; Plant Diseases - genetics; Plant Diseases - immunology; Plant Diseases - microbiology; Plant Proteins - genetics; Plant Proteins - immunology; plantlets; reverse transcriptase polymerase chain reaction; Rhizoctonia - immunology; Rhizoctonia - physiology; roots; Thanatephorus cucumeris; Trichoderma - physiology; hypersensitive response; lipoxygenase; Trichoderma; glutathione S-transferase; Three-way interaction; Rhizoctonia solani; deoxycytidine deaminase; Plant pathogen; Enzyme; Transferases; Interaction; Fungi; Resistance; Trichoderma harzianum; Brassica oleracea; Cruciferae; Glutathione transferase; Dicotyledones; Angiospermae; Spermatophyta; Fungi Imperfecti; Oxidoreductases; Lipoxygenase
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf3025634

Plant interactions with microbial biocontrol agents are used as experimental models to understand resistance-related molecular adaptations of plants. In a hydroponic three-way interaction study, a novel Trichoderma harzianum ETS 323 mediated mechanism was found to induce resistance to Rhizoctonia solani infection in Brassica oleracea var. capitata plantlets. The R. solani challenge on leaves initiate an increase in lipoxygenase activity and associated hypersensitive tissue damage with characteristic “programmed cell death” that facilitate the infection. However, B. oleracea plantlets whose roots were briefly (6 h) colonized by T. harzianum ETS 323 developed resistance to R. solani infection through a significant reduction of the host hypersensitive tissue damage. The resistance developed in the distal leaf tissue was associated with the expression of a H2O2-inducible glutathione S-transferase (BoGST), which scavenges cytotoxic reactive electrophiles, and of a deoxycytidine deaminase (BoDCD), which modulates the host molecular expression and potentially neutralizes the DNA adducts and maintains DNA integrity. The cDNAs of BoGST and BoDCD were cloned and sequenced; their expressions were verified by reverse-transcription polymerase chain reaction analysis and were found to be transcriptionally activated during the three-way interaction.