Staying Hydrated: The Arabidopsis root microbiome produces flavonoid-attracted Aeromonas sp. to keep plants from being dehydrated.

By: Victoria Spring

Human-induced climate change is the most significant threat to the natural environment and societies worldwide. Climate change has also led to more intense extreme weather, such as heatwaves, which elevate plant exposure to abiotic stresses. Due to heat exposure, plants undergo abiotic stresses, such as dehydration, boosting flavonoid production. Flavonoids are micronutrients that occur naturally in plants as secondary metabolites needed to induce plant and microbe interactions. Although known for initiating legume rhizobia nodulation, the effect and contribution of flavonoids within non-nodulating bacteria to plant stress remains unknown. It's important to note that flavonoids diversify the Arabidopsis root microbiome while favoring Aeromonadaceae and the cultivable Aeromonas sp. H1. Strain H1 displayed enhanced plant characteristics and dehydration resistance requiring flavonoids, although not through the sudden "cry-for-help" action due to stress, which was initially hypothesized in the study. Strain H1 boosted dehydration-induced H2O2 (hydrogen peroxide accumulation in guard cells and stomatal closure, concomitant with synergistic induction of jasmonic acid-related regulators of plant dehydration resistance. The research findings in this study showed the importance of flavonoids and the critical process of plant microbiome interaction mediation with the inclusion of dehydration resistance within bacteria-enhanced plants.

Fig.3 These graphs of the Aeromonas sp. H1 show the impact on plant dehydration.

Original Article:

He, D., Singh, S.K., Peng, L. et al. Flavonoid-attracted Aeromonas sp. from the Arabidopsis root microbiome enhances plant dehydration resistance. ISME J 16, 2622–2632 (2022). https://doi.org/10.1038/s41396-022-01288-7