Harnessing the power of microbes for plant protection in regenerative agriculture: A comprehensive review
A Sowmiya, M Suganthy, R. Saranya, K. Ganesan, P. Janaki
Abstract
The shift toward regenerative agriculture has intensified interest in sustainable plant protection strategies that prioritize ecological balance, soil health and long-term productivity. Among these, the use of beneficial microbes has garnered significant attention for their ability to enhance plant defense, suppress pests and diseases and improve overall crop resilience. This review highlights the growing relevance of microbial agents in advancing sustainable plant protection and examines their potential applications within regenerative agricultural systems that emphasize reduced chemical inputs and ecological harmony. It explores key microbial groups including plant growth-promoting rhizobacteria (PGPR), mycorrhizal fungi, endophytes and biocontrol agents and extrapolates their contributions to plant health through mechanisms such as nitrogen fixation, phosphorus solubilization, phytohormone production, systemic resistance induction and antagonism of pathogens and insect pests. Particular emphasis is placed on entomopathogenic fungi, Beauveria bassiana , Metarhizium spp ., Isaria spp ., and Verticillium spp ., the bacteria, Bacillus thuringiensis , entomopathogenic nematodes, Heterorhabditis and Steinernema spp . and entomopathogenic protozoa, Nosema spp ., all of which have demonstrated efficacy in controlling a broad spectrum of insect pests. These microbes act through multiple mechanisms, including enzymatic degradation of the insect cuticle, toxin-mediated mortality, interference with host metabolism, septicemia induced by nematode–bacterial symbiosis and long-term host suppression by protozoan infection, making them versatile agents in integrated pest management strategies. This review critically examines their efficacy, specificity, advantages and limitations under both laboratory and field conditions. It further explores challenges related to formulation stability, environmental persistence, delivery systems and compatibility with regenerative practices such as organic amendments and conservation tillage. Real-world case studies and field-based evidence are presented to underscore the practical relevance and scalability of microbial-based pest management. The review concludes that beneficial microbes not only offer effective pest suppression but also enhance plant growth and stress resilience, positioning them as vital tools for regenerative agriculture. Their integration into farming systems represents a biologically sound, ecologically responsible and scalable pathway toward sustainable agricultural transformation. • Beneficial microbes are pivotal for sustainable plant protection within regenerative agriculture frameworks. • Key microbial groups such as PGPR, mycorrhizal fungi, endophytes, and biocontrol agents bolster plant health through diverse mechanisms including nutrient acquisition, phytohormone production, and pest/pathogen suppression. • Entomopathogenic fungi and Bacillus thuringiensis exhibit strong potential for biological pest control through multiple modes of action. • Critical evaluation reveals challenges in formulation, environmental persistence and integration with regenerative practices like organic amendments and conservation tillage. • Field-based case studies confirm that microbial agents can enhance crop resilience, reduce chemical inputs, and support ecological balance in scalable regenerative agriculture systems.