Biocontrol Potentials of Antimicrobial Peptide Producing Bacillus Species: Multifaceted Antagonists for the Management of Stem Rot of Carnation Caused by Sclerotinia sclerotiorum

Abstract

Bacillus species are widely exploited as biocontrol agents because of their efficiency in impeding various plant pathogens with multifaceted approach. In this study, Bacillus species were isolated from rhizosphere of various plants viz., carnations, cotton, turmeric, and bananas in Tamil Nadu state of India. Their potential to control the mycelial growth of Sclerotinia sclerotiorum was assessed in vitro by dual plate and partition plate techniques. B. amyloliquefaciens strain VB7 was much effective in inhibiting mycelial growth (45% inhibition of over control) and sclerotial production (100%). PCR detection of AMP genes revealed that B. amyloliquefaciens (VB7) had a maximum of 10 diverse antibiotic biosynthesis genes, namely, ituD, ipa14, bacA, bacD, bamC, sfP, spaC, spaS, alba, and albF, that resulted in production of the antibiotics iturin, bacilysin, bacillomycin, surfactin, subtilin, and subtilosin. Further, metabolites from B. amyloliquefaciens strains VB2 and VB7, associated with inhibition of S. sclerotiorum, were identified as phenols and fatty acids by gas chromatography mass spectrometry (GC-MS). Delivery of bacterial suspension of the effective strains of Bacillus spp. as root dip was found promising for the management of stem rot of cultivated carnations. Minimal percent disease incidence (4.6%) and maximum plant growth promotion was observed in the plants treated with B. amyloliquefaciens (VB7).

Plant growth promoting and antifungal activity in endophytic Bacillus strains from pearl millet (Pennisetum glaucum)

“…Analogous to earlier reported research findings, the present study also confirmed the role of antifungal peptide-mediated mechanism in the effective inhibition of RS, FS, and SR. Besides, PCR based amplification of AMP biosynthetic genes (srfA, bmyC, and ituD) in all the endophytic strains has established the occurrence of these gene(s) at the molecular level, and reflected homology with earlier reported antibiotic genes in Bacillus strains [43,76]. Phylogenetic tree based on these three distinct AMP genes also bestow a clear cut connotation of the homology.…”

Antifungal activity of Bacillus subtilis subsp. spizizenii (MM19) for the management of Alternaria leaf blight of marigold

“…The compounds Phenol, 2,4-bis(1,1-dimethylethyl)-and 1,2-Benzenedicarboxylic acid, bis(2-methylpropyl) ester possess antimicrobial nature (Santhi et al, 2013). Similarly, nonvolatile metabolites like octadecenoic acid, hexadecenoic acid, heptadecenoic acid, pyrrolo, chloroxylenol and pentadecenoic acid produced by B. amyloliquefaciens VB7 effectively suppressed stem rot of carnation incited by Sclerotinia sclerotiorum under protected conditions (Vinodkumar et al, 2017). Besides, Dheepa et al (2016) demonstrated the antifungal nature of nonvolatile compounds like benzene, 1-Dodecene, Benzaldehyde, à-Dodecene, Nonadecene, Octadecanoic acid and n-Tetradec-1-ene produced by B. subtilis (BS2) against Puccini a horiana in chrysanthemum.…”

Bacillus megaterium WL-3 Lipopeptides Collaborate Against Phytophthora infestans to Control Potato Late Blight and Promote Potato Plant Growth

“…For example, Bacillus mycoides 15A-B2 was effective in controlling late blight severity by promoting potato plant growth ( Caulier et al, 2018 ). Additionally, B. amyloliquefaciens VB7 and its CLPs promoted the growth of carnation stem cuttings, thus increasing flower yield ( Vinodkumar et al, 2017 ). Similarly, our studies show that Iturin A and Fengycin A, either alone or in combination, had the exquisite ability to control late blight severity in greenhouse experiments as a result of promoting potato plant growth which was measured by the parameters PH, MSD, MRN, and PPY.…”