Biological Control of Verticillium Wilt and Growth Promotion in Tomato by Rhizospheric Soil-Derived Bacillus amyloliquefaciens Oj-2.16

Abstract

Verticillium wilt disease caused by Verticillium dahliae seriously affects tomato quality and yield. In this work, strain Oj-2.16 was isolated from rhizosphere soil of the medicinal plant Ophiopogon japonicas and identified as Bacillus amyloliquefaciens on the basis of morphological, physiological, and biochemical characteristics and 16S rDNA sequencing. Strain Oj-2.16 exhibited a high inhibition rate against V. dahliae, and the hyphae inhibited by Oj-2.16 were found to be destroyed on scanning electron microscopy. Lipopeptide and dipeptide genes were detected in the Oj-2.16 genome by PCR amplification involved in surfactin, iturin, fengycin, and bacilysin biosynthesis. In pot experiments, the biocontrol efficacy of strain Oj-2.16 against Verticillium wilt in tomato was 89.26%, which was slightly higher than the efficacy of the chemical fungicide carbendazim. Strain Oj-2.16 can produce indole acetic acid, siderophores, assimilate various carbon sources, and significantly promoted the growth of tomato seedlings by increasing plant height, root length, stem width, fresh weight, and dry weight by 44.44%, 122.22%, 80.19%, 57.65%, 64.00%, respectively. Furthermore, defense-related antioxidant CAT, SOD, POD, and PAL enzyme activities significantly increased and MDA contents significantly decreased in tomato seedlings treated with strain Oj-2.16 upon inoculation of V. dahliae compared with the pathogen-inoculated control. In summary, we concluded that B. amyloliquefaciens Oj-2.16 could be used as a promising candidate for the biocontrol of Verticillium wilt and as plant growth stimulator of tomato.

Cyclic Lipopeptides of Bacillus amyloliquefaciens DHA6 Are the Determinants to Suppress Watermelon Fusarium Wilt by Direct Antifungal Activity and Host Defense Modulation

“…The induction of plant defense responses by CLPs was further confirmed by the increased activity of antioxidative enzymes, i.e., CAT, SOD, and POD ( Figure 8 A), in watermelon plants upon CLPs pretreatment, supporting the notion that CLPs pretreatment induced plant innate defense mechanisms to suppress Fusarium wilt development. Similar results have been reported in infected watermelon and tomato plants, where B. velezensis F21 and B. amyloliquefaciens Oj-2.16 induced the activities of CAT, POD, and SOD through the production of antioxidant-triggering CLPs [ 12 , 73 ]. The plant immune system is believed to rely on coordinated signaling pathways, including SA, JA, and ET pathways, to mount an effective defense response against pathogen attack [ 12 ].…”

Unraveling verticillium wilt resistance: insight from the integration of transcriptome and metabolome in wild eggplant

“…The enhanced activities of antioxidant enzymes can effectively scavenge harmful reactive oxygen species to maintain the stability of plant defense systems ( Mittler et al., 2022 ). In tomato seedlings, the enzyme activities of the defense-related antioxidants CAT, SOD, POD, and PAL significantly increased upon inoculation with V. dahliae compared to controls ( Pei et al., 2022 ). The activities of POD and PAL in cotton increased due to the infection of the V991 strain ( Xu et al., 2011a ).…”

Biological Control of Root Rot of Strawberry by Bacillus amyloliquefaciens Strains CMS5 and CMR12

“…When plants are damaged, the disruption of the reactive oxygen metabolism system leads to an increase in the MDA content in lipids, increases membrane permeability, and reduces plant resistance [ 64 , 65 ]. Pei et al [ 66 ] showed that B. amyloliquefaciens Oj-2.16 enhances resistance in tomato plants to Verticillium wilt by increasing the activities of defense-related enzymes CAT and SOD. Compared to tomato seedlings inoculated with V. dahliae , the treated with strain Oj-2.16 exhibited significantly reduced MDA content.…”