Unseen Struggles: How Plant-Parasitic Nematodes Manipulate ROS Signaling in Host Plants.

Reactive oxygen species (ROS) play a central role in plant defense, especially during interactions with plant-parasitic nematodes (PPNs). These molecules act as early signals that activate immune responses and help reinforce plant cell walls to block nematode invasion. However, PPNs have evolved specialized effector proteins (small, secreted molecules, typically proteins, that enter host cells to directly suppress immunity and manipulate host processes), which they secrete into host tissues and cells to interfere with ROS production and signaling. These effectors can suppress ROS bursts, detoxify reactive molecules, or manipulate host pathways to reduce immune responses. This review synthesizes current knowledge on these effector-driven strategies, from their discovery using advanced genomics to their specific molecular mechanism of ROS suppression. We also explore the critical interplay between ROS signaling and plant hormone pathways during infection and provide an overview of the key techniques used to detect and quantify ROS in plant-nematode interactions. [Formula: see text] Copyright © 2026 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.