Effect of oral secretion of stink bug Nezara viridula on developing soybean seeds at morphological and biochemical level.

GIACOMETTI ROMINA; CUÉLLAR GARCIA DIEGO; TEJEDOR MARIA DANIELA; ILINA NATALIA; PAGANO EDUARDO; ZAVALA JORGE

Mar del Plata

Congreso; SAIB Annual Meeting Argentine Society for Biochemistry and Molecular Biology; 2015

Nezara viridula has become a serious invasive pest of agriculture in South America and its oral secretion is believed to be responsible for the damage it causes particularly in soybean (Glycine max) crop. The high level of injure to seeds caused by pentatomids is related to their feeding behaviour, morphology of mouth parts, and saliva, though no information about the specific composition is available yet. On the other hand, plants respond to the attack recognizing cell injury and oral secretions, triggering mitogen activated protein kinases (MAPK) pathway and inducing defenses against herbivores. Soybean MAPK?s role in mediating responses to insects attack remains largely unexplored. Field studies were conducted to evaluate the superficial damage produced by herbivory to soybean seeds by scanning electronic microscopy (SEM). We also determined by protein gel analysis that the suite of proteins comprising the stink bug watery saliva are very distinct depending on the diet. We also examined the early MAPKs involvement in defense modulation and late activity response of Phe-ammonia lyase (PAL) and lipoxygenase (LOX) enzymes. Lastly, after insect attack saliva affected the expression of the salicylate inducible pathogenesis related gene PR1. Our results suggest that stink bug saliva may elicit a plant self-protection response not only increasing MAPK activity, but also triggering a tightly regulated induction of SA and JA-mediated defenses.