Silencing of the Alkaline α-Galactosidase Gene Impairs Root and Gall Development in Cucumber upon Infection.

() is a devastating root-knot nematode that parasitizes a broad range of crop species by inducing the formation of giant cells (GCs) in host roots, thereby facilitating nutrient acquisition. This process profoundly alters host sugar metabolism, yet the molecular regulators underlying sugar dynamics during infection remain poorly understood in cucumber. In this study, we investigated the role of the cucumber alkaline α-galactosidase gene () in -infected roots. Histochemical analysis of ::GUS transgenic lines demonstrated that is spatially localized to nematode-induced feeding sites, with its expression markedly induced in GCs and phloem-adjacent tissues during infection. Functional analyses revealed that silencing impaired root and gall development. -silenced plants exhibited increased gall numbers (per gram root) but significantly reduced root growth and smaller galls compared to controls. These results indicate that is required for proper gall expansion and root growth during infection. This study provides novel insight into the sugar-mediated regulation of host-nematode interactions, and emerges as a potential target for the biological control of .