Nezara viridula reveals intestinal specialization when feeding on corn

Chinese researchers have uncovered how the intestines of Nezara viridula divides functions among its segments to deal with food and toxins present in corn. Gene expression analysis in the M1, M2 and M3 sections of the insect's midgut revealed a system organized along three axes: metabolism, defense and regeneration. These findings offer clues about possible molecular targets for ecological management strategies for the pest.

The M1 region, located in the anterior portion of the intestine, concentrates nutrient digestion and detoxification. Genes associated with carbohydrate, lipid and amino acid metabolism show high activity. Signs of secondary metabolite biosynthesis and signaling pathways, such as calcium and cAMP, indicate precise regulation of digestion. The high expression of receptors such as TACR and HTR suggests a relevant role in the response to food stimuli.

The intermediate portion, M2, assumes structural and immunological functions. Pathways related to cell junctions, phagocytosis and cell-matrix interaction dominate this section. Genes such as ITGA8 and MUC5 are more active in this area, reinforcing the hypothesis that the segment acts as a physical barrier and a point of communication between cells, in addition to participating in defense against pathogens.

The M3 segment, located at the end of the midgut, shows activity focused on cell renewal. Pathways associated with senescence and the cell cycle stand out, along with the expression of genes linked to the biosynthesis of structural components. The high activity of genes such as GLA and NAGA in galactose metabolism pathways also suggests a role in the final processing of nutrients before excretion.

Data integration with advanced bioinformatics tools such as GSEA and ReporterScore allowed us to accurately identify the metabolic pathways and regulatory signals active in each segment. Topological analysis revealed complex functional networks, with specific interconnected modules that explain the insect's adaptability to plant food.

This model of functional compartmentalization, classified as “metabolism–defense–regeneration”, helps to understand how Nezara viridula adapts to the chemical defenses of plants. The presence of specific neuroactive receptors and digestive enzymes in different regions of the intestine reveals an evolutionary specialization that favors the pest's nutritional flexibility.

In addition to clarifying fundamental aspects of the digestive physiology of hemipterans, the study suggests promising targets for selective control of the pest. Interference in genes such as TACR, HTR, GLA or NAGA can compromise essential functions in specific regions of the intestine, paving the way for new-generation insecticides with lower environmental impact.

The systematic approach adopted—which combines expression analysis, functional enrichment, and network mapping—serves as a model for investigations in other agricultural species. The dataset provides a solid basis for future functional experiments and for the development of biotechnological tools aimed at rational insect control.

More information at doi.org/10.3390/insects16060634