WIKIMEDIA, ALBERTO SALGUEROScientists are finally getting a glimpse into how defense hormones shape plant health both above and below the soil, thanks to a study published today (July 16) in Science. The results show how an Arabidopsis thaliana defense hormone, salicylic acid, which helps protect the health of the plant’s shoots and leaves, also guides the growth of microbial communities in and around its roots.
“This is the first study that really tied this phytohormone to the microbiome associated with the root,” said Xinnian Dong, a professor of biology at Duke University who was not affiliated with the work.
Commensal root microbes can confer numerous benefits to a plant, including increased tolerance to environmental stressors like heat, drought, and acidity, and aid in the plant’s acquisition of nutrients. However, little is known about how plants might influence their underground microbial communities, or how a plant’s immune system interacts with the bacteria it encounters in the soil.
To explore these interactions, the University of Tennessee’s Sarah Lebeis and her colleagues grew mutant strains of A. thaliana that were deficient in either the biosynthesis or signaling detection of different key defensive immune ...