The effects of strigolactones on the microbiome of rice
Abstract
Strigolactones are endogenous plant hormones regulating plant development and they are exuded by the roots when plants experience nutrient deficient conditions. The latter promotes the mutualistic association with arbuscular mycorrhizal fungi that help the plant to uptake valuable nutrients from the soil. This shows that plant actively establish symbiotic interactions with microbes to overcome inadequate nutrition and that strigolactones play an important role in this. Despite this important role as rhizosphere signaling molecules, the effect of strigolactones on the global root and rhizosphere microbiome remains poorly understood. Therefore, we conducted metabarcoding analysis on 16 rice genotypes quantitatively differing in strigolactone production to elucidate if bacteria and other fungi respond to strigolactones. Using multivariate analyses, we were able to pinpoint distinctive differences in the microbiome composition depending on strigolactones exudation. Using multivariate regression modeling and machine learning analysis we could show that several groups of microorganisms correlate with strigolactones. This suggests that strigolactones also play a role in the recruitment of other players in the microbiome. Further studies will assess the functional role of these microbiome changes and will further unravel this new role for strigolactones as a rhizosphere signaling molecule.