Plant Reproductive Suppression Triggers Fatty Acid-Mediated Enrichment of <i>Mortierella</i> for Enhanced Stress Resilience

Reproductive growth suppression enhances plant productivity, yet its effects on the health and survival strategies of perennial flowering plants remain underexplored. This study investigates the trade-offs between growth and reproduction in Panax notoginseng, focusing on its relationship with rhizosphere microbiome. Through three-year, multi-site field experiments coupled with metabolomic and microbiome analyses, we demonstrate that suppressing reproductive growth significantly increases biomass, particularly in underground tissues. Mechanistically, this suppression activates fatty acid biosynthesis pathways, leading to the reallocation of fatty acid metabolites from aboveground to belowground tissues and enhancing the rhizospheric secretion of palmitic, oleic, linoleic, and stearic acids. These fatty acids specifically promote the growth of beneficial fungus Mortierella, which supports plant health and progeny development. Exogenous application of these fatty acids in field conditions further confirmed their role in enriching Mortierella, thereby improving plant productivity. Our findings uncover a microbial-mediated survival strategy in plants under reproductive suppression, offering mechanistic insights for sustainable rhizosphere management in perennial crops.