Foliar application of Burkholderia sp. strain TNAU-1 leads to activation of defense responses in chilli (Capsicum annuum L.)

induction of phenolics, peroxidase (po), polyphenol oxidase (ppo), chitinase and thaumatin-like proteins (tlp) in leaves of chilli (capsicum annuum l.) in response to foliar application with a biocontrol agent burkholderia sp. strain tnau-1 was studied. chilli plants, when sprayed with burkholderia sp. strain tnau-1 showed increase in phenolic content one day after application and the maximum accumulation was observed seven days after treatment. three new peroxidase isozymes (po-1, po-2 and po-3) were induced in chilli leaves upon treatment with burkholderia sp. strain tnau-1. the activity of all the peroxidases was at the maximum level three days after treatment and subsequently decreased. protein extracts obtained from burkholderia sp. strain tnau-1 treated plants exhibited a major polyphenol oxidase (ppo-1) one day after treatment. the activity of ppo-1 subsequently decreased, but continuously present throughout the experimental period of 15 days. western blot analysis of protein extracts from burkholderia sp. strain tnau-1 treated chilli leaves revealed that two tlps with sizes of 23 and 25 kda and a chitinase with an apparent molecular weight of 28 kda were induced three days after treatment.