# Silencing of the Alkaline α-Galactosidase Gene CsAGA1 Impairs Root and Gall Development in Cucumber upon Meloidogyne incognita Infection

## TL;DR

This study shows that a cucumber gene, CsAGA1, is important for root and gall development during infection by a root-knot nematode, suggesting it could be a target for biological control.

## Contribution

The study identifies CsAGA1 as a novel gene involved in regulating root and gall development during nematode infection in cucumber.

## Key findings

- CsAGA1 is expressed in nematode-induced feeding sites and phloem-adjacent tissues during infection.
- Silencing CsAGA1 leads to increased gall numbers but reduced root growth and smaller galls.
- CsAGA1 is essential for proper gall expansion and root development during nematode infection.

## Abstract

Meloidogyne incognita (M. incognita) 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 (CsAGA1) in M. incognita-infected roots. Histochemical analysis of proCsAGA1::GUS transgenic lines demonstrated that CsAGA1 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 CsAGA1 impaired root and gall development. CsAGA1-silenced plants exhibited increased gall numbers (per gram root) but significantly reduced root growth and smaller galls compared to controls. These results indicate that CsAGA1 is required for proper gall expansion and root growth during M. incognita infection. This study provides novel insight into the sugar-mediated regulation of host–nematode interactions, and CsAGA1 emerges as a potential target for the biological control of M. incognita.