Isolation and Characterization of Endophyte Bacillus velezensis KOF112 from Grapevine Shoot Xylem as Biological Control Agent for Fungal Diseases

Abstract

As the use of chemical fungicides has raised environmental concerns, biological control agents have attracted interest as an alternative to chemical fungicides for plant-disease control. In this study, we attempted to explore biological control agents for three fungal phytopathogens causing downy mildew, gray mold, and ripe rot in grapevines, which are derived from shoot xylem of grapevines. KOF112, which was isolated from the Japanese indigenous wine grape Vitis sp. cv. Koshu, inhibited mycelial growth of Botrytis cinerea, Colletotrichum gloeosporioides, and Phytophthora infestans. The KOF112-inhibited mycelial tips were swollen or ruptured, suggesting that KOF112 produces antifungal substances. Analysis of the 16S rDNA sequence revealed that KOF112 is a strain of Bacillus velezensis. Comparative genome analysis indicated significant differences in the synthesis of non-ribosomal synthesized antimicrobial peptides and polyketides between KOF112 and the antagonistic B. velezensis FZB42. KOF112 showed biocontrol activities against gray mold caused by B. cinerea, anthracnose by C. gloeosporioides, and downy mildew by Plasmopara viticola. In the KOF112–P. viticola interaction, KOF112 inhibited zoospore release from P. viticola zoosporangia but not zoospore germination. In addition, KOF112 drastically upregulated the expression of genes encoding class IV chitinase and β-1,3-glucanase in grape leaves, suggesting that KOF112 also works as a biotic elicitor in grapevine. Because it is considered that endophytic KOF112 can colonize well in and/or on grapevine, KOF112 may contribute to pest-management strategies in viticulture and potentially reduce the frequency of chemical fungicide application.

Suppression of Grape White Rot Caused by Coniella vitis Using the Potential Biocontrol Agent Bacillus velezensis GSBZ09

“…Bacillus spp. exhibit broad-spectrum biological activities against various phytopathogens [7,27], and B. velezensis has been reported to have good antifungal activity against fungal pathogens on grapes, such as B. cinerea, C. gloeosporioides and P. viticola [25,28]. In this study, nine antagonistic Bacillus isolates out of 50 rhizobacterial isolates were screened with C. vitis as targets.…”

“…Moreover, gene clusters for the biosynthesis of secondary metabolites were identified in B. velezensis, including surfactin, iturin, bacillomycin, fengycin, mycosubtilin, bacillaene, and bacilysin, most of which exhibit a wide range of antimicrobial activities [24]. B. velezensis strain KOF112 was isolated from the xylem of grape buds, showed good antifungal activity against Botrytis cinerea, Colletotrichum gloeosporioides and Plasmopara viticola, and significantly upregulated the expression of genes encoding class IV chitinases and β-1,3 glucanase in grape leaves [25]. B. velezensis Bvel1 produces various metabolites, including iturin A2, surfactin-C13 and C15, oxydifficidin, bacillibactin, l-dihydro anticapsin and azelaic acid [26].…”

Available Strategies for the Management of Andean Lupin Anthracnose

“…+ triazoles site + C14-demethylase in sterol biosynthesis G1/3 [38] B. subtilis microbial Multiple effects antibiosis, membrane disruption by fungicidal lipopeptides, lytic enzymes, induced plant defense BM 02 [59,95,115] * Biochemical mode of action given by the Fungicide Resistance Action Committee (FRAC). Fungicides groups are classified according to their risk level of developing resistance [114].…”

“…In addition, several species of wild lupin, such as lupin afelpado (L. alopecuroid-es), lupin rastrero (L. sarmentosus), miniature lupin or allpa chocho in Quechua language (L. microphyllus), or B. subtilis for control of lupin anthracnose is also listed in Table 4. Application of sus-pensions based on B. subtilis [59,99,115] into a rotation with foliar fungicide containing mancozeb, chlorothalonil, or azoxystrobin [38,116,117] at sowing, plant emergence, early flowering, and early pod formation can better prevent transmission of the pathogen to the seedling and suppress anthracnose in the field. Using a biocontrol agent can reduce damage to human health and the environment.…”

“…Success in controlling lupin anthracnose disease can be achieved with a sequential two-week application [ 99 ]. Shorter interval applications of B. subtilis are often recommended during the rapid growth stages of the plant to obtain a commercially acceptable product [ 115 ]. Special attention should be given to cotyledonal, early flowering, full bloom, and pod-filling stages ( Figure 8 ) because lupin has been shown to be more anthracnose susceptible at these phenological stages [ 100 , 102 , 121 , 122 ].…”