Thiorredoxin from Anticarsia gemmatalis against soybean (Glycine max) proteases inhibitors

TEJEDOR, M.D.; GIACOMETTI R; ILINA N; KLINKE S; CERRUTI M.L.; OTERO L.H.; ZAVALA J.A.; WOLOSIUK R.A.; PAGANO EA

Mar del Plata

Congreso; Ll Reunión Anual Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2015

SAIB

Anticarsia gemmatalis is a major pest of soybean (Glycine max). However, soybean has digestive protease inhibitors (PI) that act as defense against insects attack. Although these PIs are an effective defense against many herbivores the mortality of A. gemmatalis is very low. Since thioredoxins proteins (Trx) are able to reduce disulfide bonds in some proteins, we believe Trx from the gut of A. gemmatalis could be a key component in the resistance to the soybean PI defense. Given that AgTrx has not been previously characterized, the aim of this study was to analyze Trx expression from guts of larvae that fed on diets with different levels of PIs. We found that the expression of insect Trx was stimulated by the presence of inhibitors in the diet. Full length AgTrx was cloned, sequenced and expressed in E. coli in order to accurately measure its specific activity. Additionally, we solved its three-dimensional structure by X-ray crystallography at 1.95 Å resolution. These results present a first glimpse into the mechanism of AgTrx against plant defenses.