AUTHOR=Xiao Jiawen , Guo Xiaojun , Qiao Xinlei , Zhang Xuechao , Chen Xiaomeng , Zhang Dongdong 

TITLE=Activity of Fengycin and Iturin A Isolated From Bacillus subtilis Z-14 on Gaeumannomyces graminis Var. tritici and Soil Microbial Diversity

JOURNAL=Frontiers in Microbiology

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2021.682437

DOI=10.3389/fmicb.2021.682437

ISSN=1664-302X

ABSTRACT=<p><italic>Bacillus subtilis</italic> Z-14 can inhibit phytopathogenic fungi, and is used as a biocontrol agent for wheat take-all disease. The present study used the soil-borne fungus <italic>Gaeumannomyces graminis</italic> var. <italic>tritici</italic> (<italic>Ggt</italic>), which causes wheat take-all disease, and the soil microbial community as indicators, and investigated the antifungal effects of fengycin and iturin A purified from strain Z-14 using high performance liquid chromatography and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, respectively. The results showed that fengycin destroyed the internal structure of <italic>Ggt</italic> cells by digesting the cytoplasm and organelles, forming vacuoles, and inducing hyphal shrinkage and distortion. Iturin A induced cell wall disappearance, membrane degeneration, intracellular material shrinkage, and hyphal fragmentation. A biocontrol test demonstrated a 100% control effect on wheat take-all when wheat seedlings were treated with fengycin at 100 μg/ml or iturin A at 500 μg/ml. Iturin A and fengycin both reduced the relative abundance of <italic>Aspergillus</italic> and <italic>Gibberella</italic>. At the genus level, iturin A reduced the relative abundance of <italic>Mortierella</italic> and <italic>Myrothecium</italic>, while fengycin reduced that of <italic>Fusarium.</italic> Only fengycin treatment for 7 days had a significant effect on soil bacterial diversity.</p>