Expression of defense-related genes in mung bean varieties in response to Trichoderma virensalone and in the presence of Rhizoctonia solaniinfection

Web blight/wet root rot caused by Rhizoctonia solaniis one of the major constraints for mung bean (Vigna radiata) production. Growing of resistant varieties and use of biocontrol agents are the feasible options available to manage the disease. The present study was conducted to determine the variation in the expression of various defense-related genes in susceptible and resistant mung bean varieties in response to biocontrol agent Trichoderma virensand R. solaniinteractions. The primers were designed using sequences of defense-related genes, namely PR 10, epoxide hydrolase (EH), catalase and calmodulin available in NCBI database and evaluated against cDNA obtained from both susceptible and resistant mung bean plants at 1–4 days post-inoculation (dpi) with the test pathogen R. solaniand biocontrol agent T. virensusing conventional PCR and qPCR analyses. R. solaniinoculation upregulated the mean expression of PR 10 and calmodulin in susceptible and resistant varieties, respectively, whereas downregulated in the rest of the treatments. Quantitative PCR analysis showed that except catalase in the susceptible variety, which is downregulated, the expression of PR 10, EH, catalase and calmodulin was upregulated in both resistant and susceptible varieties in response to T. virensalone and in the presence of R. solani. In general, the expression of PR 10 and calmodulin was highest at 1 dpi whereas EH and catalase expression were maximum at 4 dpi. The application of T. virenssuppressed the development of disease in the presence of R. solaniin both susceptible and resistant varieties with more pronounced effect in resistant variety. Thus, the application of biocontrol agent T. virensupregulated the expression of defense-related genes and reduced disease development.