Responses of developing seeds of soybean to stink bug (Nezara viridula) attack and its effects on insect preference.

ZAVALA, J. A.; BARRIGA, L.; DILLON, F; BARNETO, J; SARDOY, P; DI SANTO, C; PAGANO, E.A.; CHLUDIL, H

Urbana

Encuentro; Joint meeting of the International Society for Chemical Ecology and the Chemical Signals in Vertebrates group.; 2014

Responses of developing seeds of soybean to stink bug (Nezara viridula) attack and its effects on insect preference ? Jorge A. Zavala, University of Buenos Aires, INBA/CONICET Lucia Barriga, Univeversity of Buenos Aires Francisco M. Dillon, University of Buenos Aires, INBA/CONICET Jesica Barneto, University of Buenos Aires, INBA/CONICET Pedro Sardoy, University of Buenos Aires, INBA/CONICET Carolina Di Santo, University of Buenos Aires, INBA/CONICET Eduardo Pagano, University of Buenos Aires, INBA/CONICET Hugo Chludil, University of Buenos Aires Presenter: Jorge A. Zavala, University of Buenos Aires, INBA/CONICET Soybean (Glycine max), the most important legume crop in South and North America, is attacked by the southern green stink bug (Nezara viridula L. Hemiptera: Pentatomidae). Temperate regions of Brazil and Argentina and the southern of U.S. states are invaded by stink bugs, which reduce soybean crop yield. Stink bugs can puncture most aboveground plant parts with their piercing-sucking mouthparts but preferentially feed on young developing seeds. Although studies have shown that plants respond to insect damage by up-regulation of defenses, most of the available evidence comes from studies that focused on leaf damage. Here we present the responses of developing seeds to stink bug damage and the effects of plant defenses on insect behavior. While stink bug attack induced early accumulation of the defense hormone jasmonic acid (JA) in seeds, 72 h after attack salicylic acid (SA) accumulation increased and JA decreased. The hormonal changes induced expression and activity of cysteine and trypsin proteases inhibitors, and expression of genes related to synthesis and perception of JA and genes related to isoflavonoid synthesis were up-regulated. Preference choice experiments demonstrated that stink bugs feed on developing seeds with low defense levels. Our results suggest that seeds respond to stink bug attack, inducing chemical defenses regulated by both SA and JA, and insects avoid seeds with induced defenses.