Secretome of the Biocontrol Agent <i>Metarhizium anisopliae</i> Induced by the Cuticle of the Cotton Pest <i>Dysdercus peruvianus</i> Reveals New Insights into Infection

<i>Metarhizium anisopliae</i> is an entomopathogenic fungus that has evolved specialized strategies to infect insect hosts. Here we analyzed secreted proteins related to <i>Dysdercus peruvianus</i> infection. Using shotgun proteomics, abundance changes in 71 proteins were identified after exposure to host cuticle. Among these proteins were classical fungal effectors secreted by pathogens to degrade physical barriers and alter host physiology. These include lipolytic enzymes, Pr1A, B, C, I, and J proteases, ROS-related proteins, oxidorreductases, and signaling proteins. Protein interaction networks were generated postulating interesting candidates for further studies, including Pr1C, based on possible functional interactions. On the basis of these results, we propose that <i>M. anisopliae</i> is degrading host components and actively secreting proteins to manage the physiology of the host. Interestingly, the secretion of these factors occurs in the absence of a host response. The findings presented here are an important step in understanding the host–pathogen interaction and developing more efficient biocontrol of <i>D. peruvianus</i> by <i>M. anisopliae.</i

Physiological and Molecular Alterations Promoted by <i>Schizotetranychus oryzae</i> Mite Infestation in Rice Leaves

Infestation of phytophagous mite <i>Schizotetranychus oryzae</i> in rice causes critical yield losses. To better understand this interaction, we employed Multidimensional Protein Identification Technology (MudPIT) approach to identify differentially expressed proteins. We detected 18 and 872 unique proteins in control and infested leaves, respectively, along with 32 proteins more abundant in control leaves. <i>S. oryzae</i> infestation caused decreased abundance of proteins related to photosynthesis (mostly photosystem II-related), carbon assimilation and energy production, chloroplast detoxification, defense, and fatty acid and gibberellin synthesis. On the contrary, infestation caused increased abundance of proteins involved in protein modification and degradation, gene expression at the translation level, protein partitioning to different organelles, lipid metabolism, actin cytoskeleton remodeling, and synthesis of jasmonate, amino acid, and molecular chaperones. Our results also suggest that <i>S. oryzae</i> infestation promotes cell-wall remodeling and interferes with ethylene biosynthesis in rice leaves. Proteomic data were positively correlated with enzymatic assays and RT-qPCR analysis. Our findings describe the protein expression patterns of infested rice leaves and suggest that the acceptor side of PSII is probably the major damaged target in the photosynthetic apparatus. These data will be useful in future biotechnological approaches aiming to induce phytophagous mite resistance in rice