A Proteomic Approach to Identify Bacillus subtilis Induced Defense Related Proteins in Noni Challenged with Meloidogyne incognita Govindasamy Kavitha1,*, Ebenezer Jonathan2, Sevugapperumal Nakkeeran3, Devi Ahila1 1Unit of Entomology, Tamil Nadu Rice Research Institute, Aduthurai-612 101, Tamil Nadu, India 2Department of Agricultural Entomology, Tamil Nadu Agricultural University, Killikulam, Tamil Nadu, India 3Department of Plant Pathology, Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu, India *Corresponding author, E-mail: kavitha_nem@yahoo.com
Online published on 26 December, 2016. Abstract Biopesticidal formulations of naturally occurring beneficial microorganisms are the most promising methods for more rational and safe crop management practices. Bacillus subtilis strains are important groups of natural antagonists that produce a broad spectrum of bioactive peptides with great potential for biocontrol of phytopathogens. Surfactin and iturin are antibiotic lipopeptides which imparts biocidal activity by direct suppression of plant-parasitic nematodes. Root-knot nematode, Meloidogyne incognita is an economically important pathogen of noni, a herbal medicine gaining popularity in India. In this investigation, endophytic strains of B.subtilis were isolated from noni plants and tested for their nematicidal activity against root knot nematode, in vitro. The genomic DNA of the Bacillus strains was isolated and amplified by PCR to identify antibiotic genes surfactin and iturin. The strain Bs 5, with high surfactin and iturin activity was found to suppress egg hatching and caused juvenile mortality. Using the ‘omic’ approaches effort were taken to understand pathogenicity and defence-related genes and proteins expressed during the three way interaction of host, pathogen and biocontrol agent during disease development. Protein profiling was done using (2-DE) two-dimensional polyacrylamide gel electrophoresis and the differentially expressed proteins were analyzed by mass spectrometry. Unique protein spots were excised and analyzed by MALDI-TOF MS/MS, followed by cross-species protein identification. A total of 15 different proteins were found to be differentially expressed. Proteomic investigations revealed that certain functionally important defense related proteins viz., Putative late blight resistance protein homolog, Toll-interleukin resistance domain containing protein, Translation Initiation factor IF1, Disease resistance protein putative Kalata-B1 and-1, 3-glucanase were induced by B. subtilis which are involved in the induction of defense response of host against the pathogen, M. incognita. Top Keywords Bacillus subtilis, Defense related proteins, Mass spectrometry, Meloidogyne incognita, Noni, Proteomics, 2D-PAGE. Top |