Biochemical responses of Anticarsia gemmatalis (Lepidoptera: Noctuidae) in soybean cultivars sprayed with the protease inhibitor berenil.

Instituto Agronomico de Campinas, Avenida Bara o de Itapura, 148, Caixa Postal 28, Campinas, Sa o Paulo (SP) 13012-970, BrazilABSTRACT: The damage caused by Anticarsia gemmatalis motivates this study on the adaptive mechanisms of the insect tosoybean. The lipoxygenase pathway produces and releases jasmonic acid, involved in the regulation of the plant defense genes,which encodes protease inhibitor (PI) production. Three soybean cultivars IAC-18, IAC-24, and Foscarin-31 were sprayed withwater and berenil, a synthetic inhibitor, at 0.60 and 1.0% (w/v) and then infested with A. gemmatalis larvae. The lipoxygenase(LOX) activity increased in the leaves of Foscarin-31, IAC-18, and IAC-24 by 87, 81, and 78%, respectively, after 24 h of A.gemmatalis damage. IAC-18 revealed the lowest increase in PI when compared to the other cultivars. Protease, amidase, andesterase activities in soybean larvae dropped drastically after berenil application. PIs may be included in the control strategies ofA. gemmatalis in soybean by lowering the digestive enzyme activity in the larval midgut, thus affecting insect growth anddevelopment.KEYWORDS: Anticarsia gemmatalis, berenil, plant−insect interaction, protease inhibitors, protein entomotoxic