PubMed · 2026-03-25
A common soil bacterium can sabotage plants by consuming the very chemicals plants release to absorb iron, leaving them iron-starved and progressively weaker. This challenges the assumption that root-associated microbes are reliably beneficial.
Pseudomonas sp. NyZ480 carries multiple redundant xenA genes that allow it to both feed on and resist coumarins — the antimicrobial, iron-mobilizing chemicals that plant roots secrete under iron stress.
NyZ480 significantly colonized iron-stressed Arabidopsis roots and trapped plants in perpetual iron scarcity, progressively impairing iron acquisition and overall plant fitness.
Bioinformatic analysis found xenA homologs to be prevalent and redundant across diverse environmental bacteria, suggesting this opportunistic, plant-harming behavior is widespread in soil microbiomes.
