Signaling role of nitric oxide in the induction of plant defense by exogenous application of abiotic inducers

Abstract

Abstract The objective of this work was to search out the probable molecule behind the activation of broad spectrum resistance during abiotic elicitors such as arachidonic acid, cupric chloride, chitosan, isonicotinic acid and salicylic acid mediated induced systemic resistance (ISR) in Raphanus sativus L. The elicitor compounds were sprayed on the radish leaves of healthy plant and after 24 h incubation a significant increase of β-1,3 glucanase, peroxidase, polyphenol oxidase and phenolics as well as a remarkable increase of nitric oxide (NO), a probable potent defense-signaling molecule in plant, was observed. Furthermore, treatment of the host with NO donor, sodium nitroprusside, also induced the same defense molecules. The results suggests that NO might be the signaling molecule during abiotic elicitor mediated ISR induction in the host system. Keywords: arachidonic acidcupric chloridechitosanisonicotinic acidsalicylic acidinduced systemic resistance Raphanus sativus β-1,3 glucanaseperoxidasepolyphenol oxidasesodium nitroprusside