Elsinochrome phytotoxin production and pathogenicity of Elsinoë arachidis isolates in China

Abstract

Peanut scab caused by Elsinoë arachidis is found throughout China’s peanut-growing areas. Elsinochrome produced by E . arachidis is a perylenequinone photosensitive mycotoxin vital to the pathogenic process of the pathogen. In this study, the complex mechanism underlying the regulation of elsinochrome biosynthesis by E . arachidis was investigated based on various nutritional and environmental factors. The initiation of elsinochrome biosynthesis depends on light. E . arachidis produced substantially more quantities of elsinochrome when grown on a semi-synthetic medium (PDA) than when grown on synthetic media with defined ingredients in the presence of light. Elsinochrome accumulation decreased when adjusted with either citrate or phosphate buffers and changing pH suppressed the radical growth. At temperatures ranging from 10°C to 25°C, the production of elsinochrome increased, peaking at 28°C, and it decreased slightly at 30°C. 63 field-collected isolates from China were assessed for the level of elsinochrome production, and pathogenicity analysis was conducted by selecting 12 strains from each 3 of the 4 groups with different levels of elsinochrome production. A direct correlation was observed between elsinochrome production and pathogenicity among the isolates. The results showed elsinochrome biosynthesis to be controlled by E . arachidis and showed elsinochrome to be a vital virulence factor of E . arachidis , required for disease severity.

Genomic analysis for Biosynthesis and Metabolic Pathway of Elsinochrome Toxin produced by Elsinoë arachidis

“…The biosynthesis of ESC in E. arachidis was signi cantly different in different light condition [47]. Under light condition, the production of ESC was 16 nmol/plug, while in the dark, no synthesis of toxins was detected.…”

“…Elsinochrome was extraction and quantitative analysis as before [47]. To estimate the expression of ESCB1 transcripts at different light condition, the strain was cultured on PDA under dark conditions for 7 days, then take part to light condition for 48 h and isolated total RNA, respectively.…”

Current status and future prospects of grapevine anthracnose caused by Elsinoe ampelina: An important disease in humid grape‐growing regions

“…ampelina are still unknown, many studies have shown that the elsinochromes produced by Elsinoe spp. are vital to the pathogenic process (Jiao et al, 2019 ; Liao & Chung, 2008 ; Wang et al, 2009 ). Elsinochromes, which are light‐dependent and nonhost‐selective phytotoxins, are structurally similar to the cercosporin phytotoxin (Yang & Chung, 2010 ).…”

Chemical, Bioactivity, and Biosynthetic Screening of Epiphytic Fungus Zasmidium pseudotsugae

“…Both metabolites are able to absorb light energy and can produce reactive oxygen species (ROS). A high amount of these toxins is reported to induce necrotic lesions on citrus and tobacco leaves [35][36][37]. 8,8′-bijuglone might exhibit similar functions in planta.…”