Abstract
Bacillus subtilis XF-1 has been used as a biocontrol agent of clubroot disease of crucifers infected by Plasmodiophora brassicae, an obligate pathogen. In order to maximize the growth inhibition of the pathogen, random mutagenesis using N-methyl-N′-nitro-N-nitrosoguanidine was applied to strain XF-1. The efficacy of 226 selected mutants was assessed against the growth of an indicator fungal pathogen: Fusarium solani using agar plate assay and the disruptive effects on the resting spores of P. brassicae. Four mutants exhibited inhibition activity significantly higher than the wild type. The cell extracts of these mutants and the XF-1 were subjected to matrix-assisted laser desorption ionization-time of flight mass spectra analysis, and three families of cyclic lipopeptides (CLPs) fengycin, surfactin and iturin were identified from the parental strain and the screened mutants. However, the relative contents and compound diversity changed after mutagenesis, and there was slight variation in the surfactin and fengycin. Notably, only 5 iturin components were discovered from the wild strain XF-1, but 13 were obtained from the mutant strains, and the relative CLPs contents of all mutant strains increased substantially. The results suggested that CLPs might be one of main biocontrol mechanisms of the clubroot disease by XF-1. The 4 mutants are far more effective than the parental strain, and they would be promising biocontrol candidates not only against P. brassicae but probably other plant diseases caused by fungi.
References
Li XY, Mao ZC, Wang YH, Wu YX, He YQ, Long CL (2012) ESI LC-MS and MS/MS characterization of antifungal cyclic lipopeptides produced by Bacillus subtilis XF-1. J Mol Microbiol Biotechnol 22:83–93
Guo SY, Mao ZC, Wu YX, Hao K, He PF, He YQ (2013) Genome sequencing of Bacillus subtilis strain XF-1 with high efficiency in the suppression of Plasmodiophora brassicae. Genome Announc 1:e00066-13
Li XY, Mao ZC, Wang YH, Wu YX, He YQ, Long CL (2013) Diversity and active mechanism of fengycin-type cyclopeptides from Bacillus subtilis XF-1 against Plasmodiophora brassicae. J Microbiol Biotechnol 23:313–321
Roongsawang N, Washio K, Morikawa M (2010) Diversity of nonribosomal peptide synthetases involved in the biosynthesis of lipopeptide biosurfactants. Int J Mol Sci 12:141–172
Ongena M, Jacques P (2008) Bacillus lipopeptides: versatile weapons for plant disease biocontrol. Trends Microbiol 16:115–125
Afsharmanesh H, Ahmadzadeh M, Majdabadi A, Motamedi F, Behboudi K, Javan-Nikkhah M (2013) Enhancement of biosurfactants and biofilm production after gamma irradiation-induced mutagenesis of Bacillus subtilis UTB1, a biocontrol agent of Aspergillus flavus. Arch Phytopathol Plant Protect 46:1874–1884
Desoignies N, Schramme F, Ongena M, Legrève A (2013) Systemic resistance induced by Bacillus lipopeptides in Beta vulgaris reduces infection by the rhizomania disease vector Polymyxa betae. Mol Plant Pathol 14:416–421
Li HG, Luo W, Gu QY, Wang Q, Hu WJ, Yu XB (2013) Acetone, butanol, and ethanol production from cane molasses using Clostridium beijerinckii mutant obtained by combined low-energy ion beam implantation and N-methyl-N-nitro-N-nitrosoguanidine induction. Bioresource Technol 137:254–260
Athukorala SNP, Fernando WGD, Rashid KY (2009) Identification of antifungal antibiotics of Bacillus species isolated from different microhabitats using polymerase chain reaction and MALDI-TOF mass spectrometry. Can J Microbiol 55:1021–1032
Hwang SF, Strelkov SE, Feng J, Gossen BD, Howard RJ (2012) Plasmodiophora brassicae: a review of an emerging pathogen of the Canadian canola (Brassica napus) crop. Mol Plant Pathol 13:105–113
Pathak KV, Keharia H (2013) Characterization of fungal antagonistic bacilli isolated from aerial roots of banyan (Ficus benghalensis) using intact-cell MALDI-TOF mass spectrometry (ICMS). J Appl Microbiol 114:1300–1310
Arguelles-Arias A, Ongena M, Halimi B, Lara Y, Brans A, Joris B, Fickers P (2009) Bacillus amyloliquefaciens GA1 as a source of potent antibiotics and other secondary metabolites for biocontrol of plant pathogens. Microbial Cell Fact 8:63
Falardeau J, Wise C, Novitsky L, Avis T (2013) Ecological and mechanistic insights into the direct and indirect antimicrobial properties of Bacillus subtilis lipopeptides on plant pathogens. J Chem Ecol 39:869–878
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This research was supported by the Ministry of Agriculture of China, for Special Fund for the Agro-scientific Research in the Public Interest (2010029030).
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Xing-Yu Li and Jing-Jing Yang contributed equally to this work.
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Li, XY., Yang, JJ., Mao, ZC. et al. Enhancement of Biocontrol Activities and Cyclic Lipopeptides Production by Chemical Mutagenesis of Bacillus subtilis XF-1, a Biocontrol Agent of Plasmodiophora brassicae and Fusarium solani . Indian J Microbiol 54, 476–479 (2014). https://doi.org/10.1007/s12088-014-0471-y
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DOI: https://doi.org/10.1007/s12088-014-0471-y