Comparative analysis of putative pathogenesis-related gene expression in potato associated with defense responses to Rhizoctonia solani

Reza Hejazi, Mehdi Nasr Esfahani, Mojdeh Maleki & Ezzatollah Sedaghatfar

Sydowia 74: 251-262

Published online on January 21st, 2022

The polyphagous necrotrophic plant pathogen Rhizoctonia solani AG3-PT (basidiomycetous teleomorph Thanatephorus cucumeris) is also an important fungal pathogen of potato (Solanum tuberosum L., Solanaceae) world-wide. Host resistant sources are the most recommenced, durable environmentally friendly method for managing the disease. Three resistant and three susceptible potato genotypes out of 92 potato genotypes screened for resistance against R. solani AG3-PT under field conditions were subjected to bio-genetic assays using PR-5, Glub2, pcht28, PR-1b, ERF4, PAL1, PIN2, LOX1 genes and ef1a as a housekeeping gene, and antioxidant enzymes including peroxidase (POX), superoxide dismutase (SOD), polyphenol oxidase (PPO), catalase (CAT) and phenylalanine ammonia-lyase (PAL1) analysis. Resistance susceptibility of the selected potato genotypes were confirmed under greenhouse conditions. Biomass parameters in susceptible genotypes decreased significantly compared to resistant genotypes. Gene expression enzyme activities increased in resistant potato genotypes inoculated with Rhizoctonia solani AG3- PT compared to susceptible controls, i.e. non-inoculated genotypes. Changes in expression levels of genes increased most in pcht28 (8.41 fold), followed by PR-1b (6), ERF4 (5), and PR-5 (5). Antioxidant enzyme activities increased most in SOD (10 fold), followed by PAL1 (4), PPO (3) POX (3). Production of potato cultivars resistant to R. solani will be possible based on changes in biomass, gene expression level, and enzyme production rate.

Keywords: antioxidant, biomass, cDNA, gene expression, RNA, qPCR, Solanum tuberosum.

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