Kurstakin Triggers Multicellular Behaviors in Bacillus cereus AR156 and Enhances Disease Control Efficacy Against Rice Sheath Blight

Abstract

Kurstakins is the latest discovered family of lipopeptides secreted by Bacillus. In this study, the effects of kurstakin on the direct antagonism, multicellularity and disease control ability of Bacillus cereus AR156 were explored. An insertion mutation in non-ribosomal peptide synthase responsible for kurstakin synthesis led to a significant reduction of antagonistic ability of AR156 against the plant pathogenic fungi Rhizoctonia solani, Ascochyta citrullina, Fusarium graminearum and F. oxysporum f. sp. cubense. The loss of kurstakin synthesis ability significantly impaired the swarming motility of AR156 and reduced biofilm formation and amyloid protein accumulation. Although the loss of kurstakin synthesis ability did not reduce the competitiveness of AR156 under laboratory condition, the colonization and environmental adaptability of the mutant was significantly weaker than that of wild type AR156 on rice leaves. Cell surface of wild type AR156 colonized on the leaf surface was covered by thick biofilm matrix under scanning electron microscope, but not in the mutant. The colonization ability on rice roots and control efficacy against rice sheath blight disease of the mutant were also impaired. Thus, kurstakin participates in the control of plant diseases by B. cereus AR156 through directly inhibiting the growth of pathogenic fungi, and improving long-term environmental adaptability and colonization of AR156 on the host surface by triggering multicellularity. This study explored the multiple functions of kurstakin in plant disease control by B. cereus.

Genome Sequencing and Characterization of Bacillus velezensis N23 as Biocontrol Agent against Plant Pathogens

“…A promising strain as a potential biocontrol agent usually has a broad-range biological activities [ 33 , 54 , 55 ]. Biocontrol bacteria exerted their biocontrol functions in the field mainly by colonizing the surface of plants, competing with pathogenic bacteria, inducing plant disease resistance, and maintaining microbiomic stability [ 12 , 20 , 35 ].…”

Plant-Associated Representatives of the <em>Bacillus cereus</em> Group Harbor a Rich Biosynthetic Potential of Antimicrobial Compounds and are Efficient in Suppressing Plant Pathogens

“…CD3-1a and CD3.5. Kurstakin is responsible for biofilm formation [56]. Although, that kurstakin was present in the majority of the investigated isolates (13/17 strains), the kurstakin gene cluster, containing the genes krsE, krsA, krsB, krsC, sfp, and krsD (Fig.…”

Plant-Associated Representatives of the <em>Bacillus cereus</em> Group Harbor a Rich Biosynthetic Potential of Antimicrobial Compounds and are Efficient in Suppressing Plant Pathogens

“…CD3-1a and CD3.5. Kurstakin is responsible for biofilm formation [54]. Although, that kurstakin was present in the majority of the investigated isolates (13/17 strains), the kurstakin gene cluster, containing the genes krsE, krsA, krsB, krsC, sfp, and krsD (Figure 4A), is not listed in the MIBiG data bank.…”