Footprint of Nitric oxide in induced systemic resistance

Nitric oxide (NO) is a potent signaling molecule with diverse physiological functions in plants. Several rhizobacterial strains may have capacity to induce systemic resistance in (ISR) plants but how far the biochemical mechanisms in which No participates in this signaling pathway is still an open question. The present study have shown in Pseudomonas aeruginosa WS-1 mediated ISR inducing system in Catharanthus roseus induces defense enzyme and phenolics and also showed a two fold increase in NO production when challenge with Alternaria alternata. Furthermore, NO donor treatment in the host produced same defense molecules in a comparable manner. From those observations it is suggested that NO might have possible signaling role in ISR during crosstalk between the ISR inducing agent and pathogen within the host system.