Isolation and Genome-Based Characterization of Biocontrol Potential of Bacillus siamensis YB-1631 against Wheat Crown Rot Caused by Fusarium pseudograminearum

Abstract

Fusarium crown rot (FCR) caused by Fusarium pseudograminearum is one of the most serious soil-borne diseases of wheat. Among 58 bacterial isolates from the rhizosphere soil of winter wheat seedlings, strain YB-1631 was found to have the highest in vitro antagonism to F. pseudograminearum growth. LB cell-free culture filtrates inhibited mycelial growth and conidia germination of F. pseudograminearum by 84.14% and 92.23%, respectively. The culture filtrate caused distortion and disruption of the cells. Using a face-to-face plate assay, volatile substances produced by YB-1631 inhibited F. pseudograminearum growth by 68.16%. In the greenhouse, YB-1631 reduced the incidence of FCR on wheat seedlings by 84.02% and increased root and shoot fresh weights by 20.94% and 9.63%, respectively. YB-1631 was identified as Bacillus siamensis based on the gyrB sequence and average nucleotide identity of the complete genome. The complete genome was 4,090,312 bp with 4357 genes and 45.92% GC content. In the genome, genes were identified for root colonization, including those for chemotaxis and biofilm production, genes for plant growth promotion, including those for phytohormones and nutrient assimilation, and genes for biocontrol activity, including those for siderophores, extracellular hydrolase, volatiles, nonribosomal peptides, polyketide antibiotics, and elicitors of induced systemic resistance. In vitro production of siderophore, β-1, 3-glucanase, amylase, protease, cellulase, phosphorus solubilization, and indole acetic acid were detected. Bacillus siamensis YB-1631 appears to have significant potential in promoting wheat growth and controlling wheat FCR caused by F. pseudograminearum.

Isolation of Bacillus subtilis and Bacillus pumilus with Anti-Vibrio parahaemolyticus Activity and Identification of the Anti-Vibrio parahaemolyticus Substance

“…Many Bacillus species have been observed to display fairly conserved 16S rRNA sequences compared to other genera, and the use of this taxonomic marker is sometimes insufficient to define the species [ 23 ]. For this reason, the analysis of additional housekeeping genes, such as gyrA , gyrB , and pycA , has been recently incorporated in order to obtain a more reliable phylogeny [ 24 , 25 , 26 , 27 ]. We additionally used the gyrB and pycA genes for the identification of Bacillus strains.…”

Antagonistic effects of Talaromyces muroii TM28 against Fusarium crown rot of wheat caused by Fusarium pseudograminearum

“…It was previously reported that Bacillus velezensis YB-185 had strong inhibitory effects on Fp mycelium growth and spore germination and significantly reduced stem basal rot in wheat ( Zhang et al, 2022 ). The inhibition rate of PDA medium containing 20 and 66% of B. siamensis YB-1631 fermentation filtrate on Fp spore germination was 84.14 and 92.23%, respectively ( Dong et al, 2023 ) In the present study, the TM28 strain of T. muroii proved to be a promising antagonistic microorganism for the control of wheat FCR caused by Fp .…”

Genomics Analysis Reveals the Potential Biocontrol Mechanism of Pseudomonas aeruginosa QY43 against Fusarium pseudograminearum

“…As reported, Trichoderma harzianum has been shown to effectively control FCR, as evidenced by Kthiri et al [13]. Additionally, Bacillus siamensis YB-1631 appears to have significant potential in promoting wheat growth and controlling wheat FCR [14]. Besides Pseudomonas fluorescens, P. putida, and P. aeruginosa in the Pseudomonas clade are important resources for developing biological control agents [15].…”