Production of desmethyl-gregatin A, a possible causative toxin of brown stem rot in adzuki bean, by Phialophora gregata f. sp. adzukicola

Moe Aizawa; Hayate Saito; Takuya Mitazaki; Takara Taketani; Keiichi Noguchi; Sho Miyazaki; Hiroshi Kawaide; Masahiro Natsume

doi:10.1584/jpestics.D22-070

Production of desmethyl-gregatin A, a possible causative toxin of brown stem rot in adzuki bean, by Phialophora gregata f. sp. adzukicola

J Pestic Sci. 2023 May 20;48(2):47-53. doi: 10.1584/jpestics.D22-070.

Authors

Moe Aizawa¹, Hayate Saito¹, Takuya Mitazaki¹, Takara Taketani¹, Keiichi Noguchi², Sho Miyazaki³, Hiroshi Kawaide⁴, Masahiro Natsume⁴

Affiliations

¹ Graduate School of Agriculture, Tokyo University of Agriculture and Technology.
² Instrumentation Analysis Center, Research Center for Science and Technology, Tokyo University of Agriculture and Technology.
³ Institute of Global Innovation Research, Tokyo University of Agriculture and Technology.
⁴ Division of Bioregulation and Biointeraction, Institute of Agriculture, Tokyo University of Agriculture and Technology.

Abstract

To elucidate the cause of brown stem rot in the adzuki bean, we re-evaluated the phytotoxins produced in cultures of the causative agent, Phialophora gregata f. sp. adzukicola. The ethyl acetate-soluble acidic fraction of the culture, as well as the neutral fraction, inhibited the growth of alfalfa seedlings. In the neutral fraction, known phytotoxins gregatin A, B, and C or D and penicilliol A were present. Although the phytotoxins in the acidic fraction were unstable, liquid chromatography-mass spectrometry analysis of the partially purified material suggested that one phytotoxin present was the non-methylated gregatin desmethyl-gregatin A (gregatinic acid A).

Keywords: Phialophora gregata; adzuki (Vigna angularis); brown stem rot; desmethyl-gregatin A; gregatin; phytotoxin.