Tryptophan metabolism and bacterial commensals prevent fungal dysbiosis in Arabidopsis roots

• DOI: 10.1073/pnas.2111521118
• Publication Date: 2021-12-01T21:50:16Z
• Authors: Katarzyna W. Woli...; Nathan Vannier; Thorsten Thiergart; Brigitte Pickel; Sjoerd Gremmen; Anna Piasecka; Mariola Piślewska...; Ryohei Thomas Nakano; Youssef Belkhadir; Paweł Bednarek; Stéphane Hacquard
• Keywords: 580; 0301 basic medicine; 2. Zero hunger; 570; Bacteria; Arabidopsis Proteins; Microbiota; Arabidopsis; Fungi; Tryptophan; Plant Development; Biological Sciences; Plant Roots; 03 medical and health sciences; Mycoses; Oomycetes; [SDE]Environmental Sciences; Dysbiosis; Symbiosis; Soil Microbiology

Significance

Understanding how host–microbe homeostasis is controlled and maintained in plant roots is key to enhance plant productivity. However, the factors that contribute to the maintenance of this equilibrium between plant roots and their multikingdom microbial communities remain largely unknown. Here, we observed a link between fungal load in roots and plant health, and we showed that modulation of fungal abundance is tightly controlled by a two-layer regulatory circuit involving the host innate immune system on one hand and bacterial root commensals on another hand. Our results shed a light into how host–microbe and microbe–microbe interactions act in concert to prevent dysbiosis in Arabidopsis thaliana roots, thereby promoting plant health and maintaining growth-promoting activities of multikingdom microbial commensals.