Induction of Oxidative Enzyme, Peroxidase in Groundnut (Arachis hypogaea) by Application of Pseudomonas fluorescens, as a Defence Against the Root-Knot Nematode, Meloidogyne arenaria Kalaiarasan P.*, Lakhsmanan P.L., Samiyappan R.1 Department of Nematology, Tamil Nadu Agricultural University, Coimbatore-641 003, India. 1Department of Plant Pathology, Tamil Nadu Agricultural University, Coimbatore-641 003, India. *E-mail: kalainem@rediffmail.com Abstract Pseudomonas fluorescens isolates Pfl, PfCBE, PfPOL and pmsR were found to protect groundnut from the root-knot nematode, Meloidogyne arenaria. Induction of peroxidase by application of P. fluorescens isolates against challenge inoculation with M. arenaria in groundnut was studied. Plant growth was significantly higher in all treatments with the bacterium. Isolate Pfl performed significantly better than the other three isolates. The bacterial treatments also reduced the level of nematode infestation. Higher levels of peroxidase activity in bacterized groundnut inoculated with nematodes were observed. Isoform analysis revealed the induction of a single PO1 isoform and higher levels of PO2 isoform in bacterized groundnut inoculated with nematodes. The nematode-suppression ability of the bacterial isolates was related to their root colonizing ability. The result suggested that induction of defense enzymes in the phenylpropanoid pathway may contribute to restriction of nematode infection in groundnut. Top Keywords Groundnut, Meloidogyne arenaria, Pseudomonas fluorescens, Peroxidase (PO), Poly Acrylamide Gel Electrophoresis (PAGE). Top |