Evaluation and Genome Mining of Bacillus stercoris Isolate B.PNR1 as Potential Agent for Fusarium Wilt Control and Growth Promotion of Tomato

Abstract

Recently, strategies for controlling <i>Fusarium oxysporum</i> f. sp. <i>lycopersici</i> (<i>Fol</i>), the causal agent of Fusarium wilt of tomato, focus on using effective biocontrol agents. In this study, an analysis of the biocontrol and plant growth promoting (PGP) attributes of 11 isolates of loamy soil <i>Bacillus</i> spp. has been conducted. Among them, the isolates B.PNR1 and B.PNR2 inhibited the mycelial growth of <i>Fol</i> by inducing abnormal fungal cell wall structures and cell wall collapse. Moreover, broad-spectrum activity against four other plant pathogenic fungi, <i>F. oxysporum</i> f. sp. <i>cubense</i> race 1 (<i>Foc</i>), <i>Sclerotium rolfsii, Colletotrichum musae,</i> and <i>C. gloeosporioides</i> were noted for these isolates. These two <i>Bacillus</i> isolates produced indole acetic acid, phosphate solubilization enzymes, and amylolytic and cellulolytic enzymes. In the pot experiment, the culture filtrate from B.PNR1 showed greater inhibition of the fungal pathogens and significantly promoted the growth of tomato plants more than those of the other treatments. Isolate B.PNR1, the best biocontrol and PGP, was identified as <i>Bacillus stercoris</i> by its 16S rRNA gene sequence and whole genome sequencing analysis (WGS). The WGS, through genome mining, confirmed that the B.PNR1 genome contained genes/gene cluster of a nonribosomal peptide synthetase/polyketide synthase, such as fengycin, surfactin, bacillaene, subtilosin A, bacilysin, and bacillibactin, which are involved in antagonistic and PGP activities. Therefore, our finding demonstrates the effectiveness of <i>B. stercoris</i> strain B.PNR1 as an antagonist and for plant growth promotion, highlighting the use of this microorganism as a biocontrol agent against the Fusarium wilt pathogen and PGP abilities in tomatoes.

Potential of Bacillus stercoris B.PNR2 to stimulate growth of rice and waxy corn under atrazine-contaminated soil

“…However, the ability of B. stercoris B.PNR2 (accession number OP592213) to stimulate the growth of rice and corn under atrazine contamination has not been tested previously (Pengproh et al, 2023). Thus, the objective of this study was to investigate the stimulation of growth in rice RD6, rice Leum Pua, and the waxy corn cultivar Muang Tam under atrazine contamination.…”