Microbial-derived natural bionematicides in sustainable agriculture: Advances in biological control of Phytonematodes.

Plant-parasitic nematodes (PPNs) are major hidden constraints in agriculture, causing significant yield losses across diverse cropping systems. Important genera such as Meloidogyne, Heterodera, Pratylenchus, and Rotylenchus exhibit complex host-parasite interactions that make their management challenging. Although chemical nematicides provide rapid control, their environment persistence, toxicity to non-target organisms, and increasing regulatory restrictions limit their long-term use. Building on this, microbial-based bionematicides have emerged as sustainable and eco-friendly alternatives. Beneficial microorganisms, including bacteria, fungi, and actinomycetes, suppress nematodes through multiple mechanisms such as toxin production, enzymatic degradation, parasitism, volatile-mediated effects, and induction of systemic resistance in plants. Recent advances in omics technologies, synthetic biology, and nanoformulations have improved the efficacy of microbial bioagents, while AI and in silico tools enhance their precision and field performance. Despite challenges in formulation and regulation, microbial bionematicides remain biodegradable, and target-specific, this review synthesizes current knowledge on microbial diversity, mechanisms of action, formulation innovations, regulatory considerations, and future directions, highlighting their pivotal role in advancing environmentally responsible phytonematode management.