Evolution and function of GH28 pectinases in cerambycid beetles: Insights from Neoclytus acuminatus

Longhorn beetles (Coleoptera: Cerambycidae) are well known for their wood-boring habits and their ability to degrade plant cell wall components using endogenous enzymes. Many of these enzymes—unlike those derived from microbial symbionts—originated via horizontal gene transfer and have diversified across cerambycid lineages. Among them, glycoside hydrolase family 28 (GH28) enzymes, which target pectic polysaccharides, have been partially characterized in the subfamily Lamiinae. However, the distribution, evolution, and function of GH28s in other subfamilies remain poorly understood, particularly in the species-rich and economically significant Cerambycinae. This study focuses on Neoclytus acuminatus, a cerambycine species that feeds on several economically important tree hosts. We investigate the molecular evolution and functional properties of GH28 in N. acuminatus through comparative phylogenetic analyses, heterologous expression in cell culture, and LC-MS-based enzymatic assays. Our findings illuminate the evolutionary trajectory of GH28 enzymes in Cerambycinae relative to other longhorn beetles and reveal lineage-specific adaptations that may contribute to ecological specialization and invasive potential. These results expand our understanding of endogenous plant cell wall-degrading enzymes in beetles and their roles in herbivory and host range expansion.