Biological control of Magnaporthe oryzae using natively isolated Bacillus subtilis G5 from Oryza officinalis roots

• DOI: 10.3389/fmicb.2023.1264000
• Publication Date: 2023-10-09T11:00:51Z
• Authors: Ling-Yun Lei; Zi-Xuan Xiong; Jin-Lu Li; De-Zheng Yang; Liu Li; Ling Chen; Qiao-Fang Zhong; Fu-You Yin; Rong-Xin Li; Zai-Quan Cheng; Su-Qin Xiao
• Keywords: Surfactin; Oryza; Secondary metabolite

Rice blast, caused by Magnaporthe oryzae, is a major threat to global rice production causing significant crop losses and impacting grain quality. The annual loss of due this disease ranges from 10% 30%. use biologically controlled strains, instead chemical pesticides, control plant diseases has become research hotspot. In study, an antagonistic endophytic bacterial strain was isolated the roots Oryza officinalis using traditional isolation culture methods. A phylogenetic tree based on 16S RNA whole-genome sequencing identified isolate G5 as Bacillus subtilis. This displayed strong effects against different physiological strains M. oryzae. After co-culture in LB medium for 7 days, inhibition rates mycelial growth four ZB15, WH97, Guy11, T-39800E were 98.07 ± 0.0034%, 98.59 0.0051%, 99.16 0.0012%, 98.69 0.0065%, respectively. Isolate significantly inhibited formation conidia with rate 97% at OD600 2. able provide 66.81% protection blast under potted conditions. Whole-genome revealed that genome size 4,065,878 bp, including 4,182 coding genes. Using anti-SMASH software, 14 secondary metabolite synthesis gene clusters predicted encode antifungal substances, such fengycin, surfactin, bacilysin. also contained genes related promotion. These findings theoretical basis expounding biocontrol mechanisms suggest further development biogenic agents could effectively inhibit pathogen reduce damage, while being environmentally friendly, conducive ecological development, sustainable alternative pesticides. study enriches relevant endophytes wild rice, which proves valuable microbial resource bank.