Gut plasma membrane proteomes reflect the distinct feeding strategies of Nezara viridula and Diaphorina citri.

Insects in the order Hemiptera have digestive systems adapted to a variety of specialized diets and feeding behaviors. We characterized the proteome of midgut brush border membrane vesicles enriched in gut surface proteins, from the immature stages of Nezara viridula that uses extraoral digestion. Proteins in triplicate samples were identified by LC-MS/MS followed by comprehensive bioinformatics analyses, including orthologous protein mapping and functional domain enrichment. We then conducted comparative proteomic analysis between N. viridula and Diaphorina citri, a phloem feeding insect with reanalysis of published D. citri proteome data. Significant differences in gut plasma membrane protein composition and abundance were noted. The gut membrane proteome of D. citri was enriched in transport proteins for sugars, amino acids, and aquaporins, which are necessary for managing the osmotic pressure of its nutrient-poor, sucrose and water rich phloem-based diet. Conversely, the gut membrane proteome of N. viridula was enriched in receptor-like proteins, lipid-binding domains, and enzymes related to nutrient absorption and detoxification, in line with its polyphagous feeding habit that necessitates extensive extraoral digestion. This study provides insights into the molecular underpinnings of gut physiology for dietary specialization, and identifies potential targets for pest management.