How beneficial microbes enhance the plant’s immune system — a phenomenon known as induced systemic resistance

In both commercial and regenerative agriculture, beneficial microbes play a crucial role in balancing the ecosystem and promoting plant health. Despite their importance, many functions of these microbes remain poorly understood due to the complexity of the microbial universe. 

Traditionally, beneficial microbes were known primarily for decomposing organic matter, thus supplying essential nutrients to plants. However, many organic regenerative farmers, including myself, have observed additional benefits from utilizing diverse microbial populations. These benefits include improved crop health, enhanced plant immunity to pests and pathogens, and better crop quality. Despite the difficulty in quantifying these observations, recent scientific discoveries have started to validate these claims.

In 1998, researchers discovered a connection between beneficial soil microbes and the enhancement of plant immune systems, a phenomenon known as Induced Systemic Resistance (ISR). This study identified jasmonic acid and ethylene as key phytohormones in the process. Initially, ISR was linked to the presence of disease-causing microbes, aligning with the conventional understanding of a body reacting to environmental stressors. Over time, numerous beneficial microbes — such as bacillus, pseudomonas, trichoderma, rhizobium, azospirillum, streptomyces, mycorrhiza, actinomycetes, serratia, paenibacillus, burkholderia, enterobacter and lysobacter — have been associated with ISR, unveiling new dimensions of plant-microbe interactions.