Identification of membrane proteins of the midgut of Zabrotes subfasciatus larvae associated with the insecticidal mechanism of PF2 lectin

The gut of insects, as well as other animals, is rich in glycoconjugates that have important biological functions required for growth and development. Interaction of lectins (carbohydrate binding proteins) with these conjugates can result in anti-physiological and insecticidal effects. PF2 lectin from Olneya tesota seeds shows insecticidal activity against Zabrotes subfasciatus larvae (bean pest). In order to evaluate the impact of plant lectins on pests, it is important to understand the composition, distribution, and physiological role of glycoconjugates present in the gut. In this study, the binding of PF2 to midgut membrane glycoproteins from 16-day-old larvae was evaluated using 2-DE (two-dimensional electrophoresis) and lectin blotting assay performed with biotinylated PF2. LC-MS/MS analysis identified several glycoproteins that could act as targets for PF2 recognition and that are involved in energy metabolism, cell motility and division, and vesicle movement among other processes. Each of these proteins is physiologically important in such a way that interference by PF2 could result in insecticidal activity.