Polyphenols induction in the defense response of calla lily towards pectobacterium carotovorum

Non-specific plant defense activators and multiple pathways for their transduction may induce resistance in plants against unrelated pathogens. This approach may reduce dependence on chemical pesticides and enhance utilization of relatively susceptible crops that maintain high marketing value. Zantedeschia is a growing crop in the ornamental bulb industry worldwide. The biggest problem in its development and production is the bacterial pathogen Pectobacterium carotovorum, the causal agent of soft-rot disease. Two plant defense activators, Bion, acting through the salicylic acid pathway, and methyl jasmonate, involving the jasmonatedependent signaling pathway, differed in both their capacity to induce accumulation of polyphenols, and resistance against the pathogen. Methyl jasmonate elicitation brought about higher accumulation of free phenolics relative to Bion, only following challenge with P. carotovorum, suggesting that priming of bioactive polyphenols plays a role in calla lily defense against this pathogen. Results demonstrate enhanced biological activity against the necrotrophic P. carotovorum only in the methyl jasmonate induced plants. To further characterize the nature of induced compounds, two major compounds were collected and identified as c-glycosylflavonoids, swertisin and isovitexin by mass and NMR spectroscopies.