Transcript and Protein Profiling Analysis of the Destruxin A-Induced Response in Larvae of <i>Plutella xylostella</i>

<div><p>Background</p><p>Destruxins (dtxs) are the mycotoxin produced by certain entomopathogenic fungi, such as <i>Metarhizium anisopliae</i>, <i>Aschersonia</i> sp, <i>Alternaria brassicae</i> and <i>Ophiosphaerella herpotrichae.</i> It can affect a wide variety of biological processes in insects, including innate immune, Ca²⁺ channel in cells, and apoptosis in a dose-dependent manner. Dtxs have been used as biological control agent for a long time, however, their molecular mechanism of action is still unknown.</p> <p>Principal Findings</p><p>In this study, both digital gene expression (DGE) and two-dimensional electrophoresis (2-DE) approaches were adopted to examine the effects of dtx A on <i>Plutella xyllostella</i> (L.) larvae. By using DGE and 2-DE analyses, 1584 genes and 42 protein points were identified as being up- or down regulated at least 2-fold in response to dtx A. Firstly, injection of dtx A to larvae accelerated the increase of peptidoglycan recognition protein (PGRP), which could activate the Toll signal pathway inducing production of antibacterial substances such as cecropin and gloverin. Dtx A also stimulated prophenoloxidase (proPO) system which plays an important role in innate immunity and leads to melanization of external organisms. Secondly, dtx A suppressed the expression of genes related to the Toll pathway, and induced expression of serine proteinase inhibitors (serpins), especially the serpin 2 that blocked process of the proPO system. Finally, other physiological process like xenobiotics detoxification, apoptosis, calcium signaling pathway and insect hormone biosynthesis, were also mediated in response to dtx A toxicity.</p> <p>Conclusions</p><p>Transcript and protein profiling analyses will provide an insight into the potential molecular mechanism of action in <i>P. xylostella</i> larvae in response to dtx A.</p>