Comprehensive N-Glycoproteomic Profiling Reveals Unexpected Glycan Diversity and Functional Specialization in the...

Protein N-glycosylation is a fundamental post-translational modification that regulates protein stability, trafficking, and molecular interactions, yet its diversity and functional significance remain poorly understood in hemimetabolous, phloem-feeding insects. The green peach aphid, Myzus persicae, is a globally important polyphagous pest and vector of numerous plant viruses, making it an ideal system for investigating the physiological and ecological roles of glycosylation. Here, we present the first comprehensive glycoproteomic characterization of M. persicae using high-resolution LC-MS/MS. We identified 43 distinct N-glycan compositions distributed across 446 glycoproteins and 1819 unique glycopeptides. The aphid N-glycome was dominated by oligomannose structures (74%), but also exhibited an unexpectedly high proportion of hybrid (14%) and complex (12%) glycans, contrasting sharply with the > 90% oligomannose dominance reported for holometabolous insects. The most abundant glycans were HexNAc(2)Hex(6) (13%), HexNAc(2)Hex(5) (11%), HexNAc(4)Hex(3) (10%), and the fucosylated paucimannose HexNAc(2)Hex(3)Fuc(1) (10%). Functional enrichment analyses revealed that glycosylation preferentially targets proteins involved in metabolism, detoxification, extracellular processes, and host-plant and virus interactions. Together, these results uncover previously unrecognized N-glycan complexity in a hemimetabolous insect and suggest that expanded hybrid and complex glycosylation may support hemimetabolous development, phloem-feeding specialization, and vector competence. This study establishes a foundational glycoproteomic resource for aphids and provides new insights into glycan-mediated mechanisms with implications for insect physiology, ecology, and the development of glycosylation-targeted pest management strategies.