Rewilding of the plant microbiome: pay-off or trade-off?

Abstract

Microbes perform many functions for plants, contributing to nutrient status, pathogen resistance, and abiotic stress tolerance. The consortium of microbes inhabiting the surfaces and internal tissues of the plant, collectively known as the microbiome, has undergone a significant shift as a result of domestication and intensive agricultural practices. Compared to wild relatives, this has led to a reduced diversity of microbes associated with crops, as well as loss of microbial functions. In response to the demand for sustainable agricultural practices, a growing emphasis has been placed on restoring beneficial functions by reintroducing both the responsible microbes and plant genes involved in these plant-microbe interactions, using wild relatives as a microbial reservoir. This process, known as “rewilding”, could improve resistance to both biotic and abiotic stresses. Translating rewilding into practice, however, will require addressing significant practical and ecological challenges. Moreover, an often-overlooked aspect is that the process of rewilding will entail trade-offs. While crop plants are typically bred for optimal growth performance under low-stress conditions, which are maintained through fertilizer and pesticide inputs, crops with a rewilded microbiome may underperform in such environments because resources are diverted toward maintaining microbial interactions. However, as rewilding may reduce fertilizer and pesticide requirements, it could ultimately lower production costs and represent an important step toward sustainable agriculture.