Redox Regulation of Plant-Root-Knot Nematode Interactions: From ROS-Mediated Immunity to Sustainable Resistance

Area of Science:

• Plant Pathology
• Molecular Plant-Microbe Interactions
• Biochemistry

Background:

• Root-knot nematodes (RKNs) cause significant crop losses globally.
• Reactive oxygen species (ROS), including superoxide radicals (O2•−) and hydrogen peroxide (H2O2), are critical in plant-nematode interactions.
• The precise role of ROS spatiotemporal regulation in determining infection outcomes requires further elucidation.

Purpose of the Study:

• To review and synthesize current evidence on the role of hydrogen peroxide (H2O2) in plant-root-knot nematode (RKN) interactions.
• To differentiate the mechanisms governing plant resistance and susceptibility based on H2O2 dynamics.
• To explore novel redox-based strategies for nematode resistance.

Main Methods:

• Literature review synthesizing molecular, biochemical, genetic, and transcriptomic data.
• Analysis of signaling pathways involved in plant defense responses to RKNs.
• Examination of nematode effectors that manipulate host ROS production and scavenging.

Main Results:

• Plant resistance to RKNs involves spatiotemporal H2O2 regulation, activating PTI-associated signaling, salicylic acid (SA) defense, and physical barriers.
• Susceptible interactions feature RKNs deploying effectors to suppress ROS production and antioxidant defenses.
• RBOH-derived ROS may limit cell death in cyst-nematode systems, with its role in RKN-induced giant cells being unclear.

Conclusions:

• The spatiotemporal dynamics of H2O2, rather than overall ROS levels, are crucial for determining the outcome of plant-RKN interactions.
• Understanding these redox mechanisms can inform the development of advanced strategies for nematode resistance.
• CRISPR/Cas editing, gene silencing, chemical priming, and biocontrol offer promising avenues for sustainable nematode management.