In a similar way to animal guts and the intestinal epithelium, plant roots are in charge of absorbing nutrients and water and of its subsequent transport to the vascular systems. These are carefully monitored by the endodermis, the innermost layer of the cortex, and its diffusion barriers, whose main role is to maintain mineral nutrient homeostasis.
But unlike animals, in which the relationship between the epithelium and the microbiota has been somewhat decoded, in plants the way the root diffusion barriers harmonizes with the resident microbiota is still to be fully comprehended.
In a paper published in the last edition of Science, a team composed of researchers from the University of North Carolina at Chapel Hill, the University of Nottingham, ITQB NOVA, Université Sine-Saloum El Hadj Ibrahima NIASSE, and the University of Bonn has shown that, in the common model plant Arabidopsis thaliana, the genes that regulate the endodermal root diffusion barrier influence the configuration of the plant microbiome, and that likewise the microbiomes that colonize the root also influence the function of the root diffusion barrier, transforming the endodermis into a regulatory hub.
It is this tight arrangement between root diffusion barriers and the microbiome that allows to keep the balance of mineral nutrients of plants and provides them a way to cope with fluctuations in mineral nutrient supplies",
Valeria Custódio, Stufy Co-Author and ITQB NOVA PhD Student affiliated with GREEN-IT Research Unit
This study not only shows a generalized role of the microbiome in controlling diffusion barrier functions across kingdoms, but it also indicates that this coordination may influence plant performance in a fluctuating environment with consequences on agriculture and food quality, possibly contributing to the future development of plants better adapted to extreme environmental conditions.
Salas-González, I., et al. (2020) Coordination between microbiota and root endodermis supports plant mineral nutrient homeostasis. Science. doi.org/10.1126/science.abd0695.