Biocontrol and Action Mechanism of Bacillus amyloliquefaciens and Bacillus subtilis in Soybean Phytophthora Blight

Abstract

With the improper application of fungicides, Phytophthora sojae begins to develop resistance to fungicides, and biological control is one of the potential ways to control it. We screened two strains of Bacillus; Bacillus amyloliquefaciens JDF3 and Bacillus subtilis RSS-1, which had an efficient inhibitory effect on P. sojae. They could inhibit mycelial growth, the germination of the cysts, and the swimming of the motile zoospores. To elucidate the response of P. sojae under the stress of B. amyloliquefaciens and B. subtilis, and the molecular mechanism of biological control, comparative transcriptome analysis was applied. Transcriptome analysis revealed that the expression gene of P. sojae showed significant changes, and a total of 1616 differentially expressed genes (DEGs) were detected. They participated in two major types of regulation, namely “specificity” regulation and “common” regulation. They might inhibit the growth of P. sojae mainly by inhibiting the activity of ribosome. A pot experiment indicated that B. amyloliquefaciens and B. subtilis enhanced the resistance of soybean to P. sojae, and their control effects of them were 70.7% and 65.5%, respectively. In addition, B. amyloliquefaciens fermentation broth could induce an active oxygen burst, NO production, callose deposition, and lignification. B. subtilis could also stimulate the systemic to develop the resistance of soybean by lignification, and phytoalexin.

Transcriptome Profiling Provides Insights Into Potential Antagonistic Mechanisms Involved in Chaetomium globosum Against Bipolaris sorokiniana

“…Similar studies were reported earlier in the antagonistic activity of Trichoderma strains synergistically producing cell wall-degrading enzymes (CWDEs) followed by production of metabolites with antibiotic functions against fungi and bacteria (Reithner et al, 2011 ; Vorapreeda et al, 2015 ). Liu et al ( 2019 ) applied transcriptomic approaches to explore the novel biocontrol mechanisms of Bacillus amyloliquefaciens and Bacillus subtilis against Phytophthora blight of soybean ( Phytophthora sojae ). In the analysis, the upregulated GO terms were the threonine-type endopeptidase activity, hydrolase activity, biosynthetic process, and proteolysis involved in mycelial degradation and protein catabolic process.…”

“…However, the molecular mechanisms of antagonism, patterns of gene expression at the molecular level, and identification of biosynthetic pathways are not yet explored in C. globosum . Transcriptome approaches have been occasionally applied to the study of biological control mechanisms (Gkarmiri et al, 2015 ; Hennessy et al, 2017 ; Liu et al, 2019 ). The present work is the first effort worldwide to unravel biocontrol mechanisms to report their probable role in the antagonism of potential C. globosum strain Cg2 against the phytopathogenic fungus B. sorokiniana isolate BS112 using RNA-seq approach.…”

Safety aspects of stingless bee pot-pollen from the Philippines

“…Most of these Bacillus spp. are associated with plants and were reported to have potential application in biomedicine and biocontrol (Liu et al, 2019;Lu et al, 2017;Jouzani et al, 2017;Prazdnova et al, 2019;Wang et al, 2017) as well as potential probiotics (Elshaghabee et al, 2017) and biofertilizer (Pramanik et al, 2019). Lysinibacillus and Paenibacillus are widespread bacteria usually considered as environmental contaminants and rarely connected to human diseases (Wenzler et al, 2015;Sannino and Angert, 2017).…”

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“…Similar studies were reported earlier in the antagonistic activity of Trichoderma strains synergistically producing cell wall-degrading enzymes (CWDEs) followed by production of metabolites with antibiotic functions against fungi and bacteria (Reithner et al, 2011;Vorapreeda et al, 2015). Liu et al (2019) applied transcriptomic approaches to explore the novel biocontrol mechanisms of Bacillus amyloliquefaciens and Bacillus subtilis against Phytophthora blight of soybean (Phytophthora sojae). In the analysis, the upregulated GO terms were the threonine-type endopeptidase activity, hydrolase activity, biosynthetic process, and proteolysis involved in mycelial degradation and protein catabolic process.…”

“…However, the molecular mechanisms of antagonism, patterns of gene expression at the molecular level, and identification of biosynthetic pathways are not yet explored in C. globosum. Transcriptome approaches have been occasionally applied to the study of biological control mechanisms (Gkarmiri et al, 2015;Hennessy et al, 2017;Liu et al, 2019). The present work is the first effort worldwide to unravel biocontrol mechanisms to report their probable role in the antagonism of potential C. globosum strain Cg2 against the phytopathogenic fungus B. sorokiniana isolate BS112 using RNA-seq approach.…”