Identification and physiological activity of (methoxymethyl)triphenylphosphonium chloride as a new phytotoxin isolated from Rhizoctonia solani AG-3 TB

Rhizoctonia solani as a cosmopolitan fungus is the causative agent of many crop diseases and leads to significant economic losses in crop production. To explore the toxin structure and its physiological activity of R. solani AG-3 TB, high performance liquid chromatography (HPLC), infrared absorption spectrum (IR) and nuclear magnetic resonance spectrum (NMR) were required. Here, the compound (methoxymethyl)triphenylphosphonium chloride (MMC) with the molecular formula C 20 H 20 ClOP was purified and identified from R. solani AG-3 TB. The pure compound MMC treated at 20 µg/mL, 50 µg/mL, and 100 µg/mL can cause obviously necrosis on leaves, increase active oxygen species (AOS), decrease chlorophyll content, and damage cellular structure. The results enrich the understanding of toxin compounds for R. solani as well as provide valuable insights for toxicology of R. solani AG-3 TB.