author(s)
KR Jadhao and GR Rout

abstract
Silicon confers stress either through physical barrier or by triggering the chemical resistance mechanism, but our understanding to silicon mediated plant resistance to pink stem borer through physiological and cytological mechanisms is underlying. Present investigation highlight silicon induced resistant against the pink stem borer, Sesamia inferens (Walker) in ragi plants. Si amendment to ragi plants much reduced the feeding ability of pink stem borer through modulation of leaf sheaths silicification. It also induces the chemical defense system by influencing the defense-related enzymes, syntheses of secondary metabolites, and concentrations of malondialdehyde, total phenol and soluble protein in a leaf sheath of infested susceptible (Suvra) and resistant (HR-379) ragi plants. Inclusion of silicon encouraged the increase of H₂O₂ concentration and suppressed the malondialdehyde concentration in both infested susceptible and resistant varieties. Superoxide dismutase, catalase and peroxidase activities were higher in both the varieties amended with silicon than in non-amended stem borer infested plants. Stem borer infestation activated synthases for secondary metabolites, phenylalanine ammonia-lyase, β-1,3-glucanase and total phenol in silicon amended plants, but performance of polyphenol oxidase and soluble protein content was lower in Si-amended plants than in non-amended plants. The present study also indicates that Si amendment interacts with stem borer infestation to confer enhanced finger millet resistance to pink stem borer by priming the reduction in soluble protein content and cell silicification of leaf sheaths, and induction of plant defense responses.