Bacillus licheniformis JF-22 to Control Meloidogyne incognita and Its Effect on Tomato Rhizosphere Microbial Community

Abstract

Meloidogyne incognita is one of the most destructive soil pests, causing serious economic losses in tomato production. Here, in vitro experiments demonstrated that the Bacillus licheniformis strain JF-22 has the potential to prevent M. incognita infection. A pot experiment confirmed that B. licheniformis strain JF-22 isolated from the tomato rhizosphere soil and planted in the tomato root-knot nematode disease area effectively prevented and controlled M. incognita, reducing its negative effect on tomato growth. Additionally, the composition of volatile substances secreted by B. licheniformis strain JF-22 was analyzed using solid-phase microextraction and gas chromatography–mass spectrometry. We detected acetoin, 2,3-Butanediol, [R-(R*,R*) ]-, and hexamethyl cyclotrisiloxane as the main components among these volatiles. Using MiSeq sequencing technology and bioinformatics, we analyzed the influence of B. licheniformis strain JF-22 on the microbial community of the tomato rhizosphere. B. licheniformis strain JF-22 changed the composition of the microbial community; particularly, it significantly reduced the diversity of the fungal community. Furthermore, using the FUNGuild and PICRUSt databases, we predicted the effect of JF-22 on microbial community function. In conclusion, B. licheniformis strain JF-22 may be considered as a potential biocontrol agent against M. incognita.

Bacillus VOCs in the Context of Biological Control

“…B. licheniformis JF-22 was another Bacillus strain recognized as a potential biocontrol agent active against Meloidogyne incognita . It was isolated from the tomato rhizosphere in the area where healthy plants were grown in the presence of the tomato root-knot nematode, and the study pointed out that acetoin, 2,3-butanediol, and hexamethylcyclotrisiloxane are the main components among the produced VOCs [ 132 ]. The VOCs produced by B. altitudinis AMCC 1040 were analyzed in the study by Ye et al [ 133 ] and grouped into four major categories: ethers, alcohols, ketones, and organic acids.…”

Microbial landscapes of the rhizosphere soils and roots of Luffa cylindrica plant associated with Meloidogyne incognita

“…Rhizosphere and root-endophytic microorganisms interact with host plants, phytopathogens, and other soil occurring microorganisms ( Yergaliyev et al, 2020 ). This interaction is fulfilled by competing nutrients, producing antimicrobial substances, and secreting volatile organic compounds ( Du et al, 2022 ). Some of the rhizosphere and root-endophytic microorganisms are reported to affect the infection of plant pests and diseases.…”

Novel Genes and Key Signaling Molecules Involved in the Repulsive Response of Meloidogyne incognita against Biocontrol Bacteria

“…Of these methods, the biological management of RKNs by antagonistic microorganisms and endophytes has gained extensive attention. , Bacillus spp. bacteria become increasingly important for achieving microbial biocontrol as they have the advantages of protecting plants from pathogens and promoting plant growth. − They have also been used as nematicides as they produce virulence proteases and chitinases, antibiotics, crystal proteins, and secondary metabolites, and activate the systemic resistance of plants, which prevents RKNs from invading plant roots …”