Metabolites and chemical agents in the plant roots: an overview of their use in plant-parasitic nematode management

Plant-parasitic nematodes are devastating phytopathogens that cause substantial economic losses in the agricultural sector. There are numerous management measures available to reduce the threat posed by plant-parasitic nematodes. One of the most effective management strategies is the use of synthetic chemical nematicides. However, many of these chemicals negatively impact the environment and health of non-target organisms, so there is great urgency for finding new environmentally safe and sustainable approaches for managing plant-parasitic nematodes. Plant roots release numerous metabolites that possess defensive properties; thus, it is imperative to understand the root-regulated interactions among plants and nematodes that form the basis for managing plant-parasitic nematodes. The present review focuses on the root metabolites and chemical agents that serve as attractants, repellents, stimulators, or inhibitors for nematodes. They influence plant resistance by modifying plant physiology to resist nematodes and can also inhibit nematode growth and development by secreting antinematode chemicals. The ultimate goal of this review is to focus mainly on the current state of knowledge on the interaction between plant roots and the potential of these compounds in management of plant-parasitic nematodes.