A Network of Phosphate Starvation and Immune-Related Signaling and Metabolic Pathways Controls the Interaction between <i>Arabidopsis thaliana</i> and the Beneficial Fungus <i>Colletotrichum tofieldiae</i>

The beneficial root-colonizing fungus Colletotrichum tofieldiae mediates plant growth promotion (PGP) upon phosphate (Pi) starvation in Arabidopsis thaliana. This activity is dependent on the Trp metabolism of host, including indole glucosinolate (IG) hydrolysis. Here, we show that C. resolves several Pi starvation-induced molecular processes one which downregulation auxin signaling germ-free plants, restored presence fungus. Using CRISPR/Cas9 genome editing, generated an triple mutant lacking three homologous nitrilases (NIT1 to NIT3) are thought link IG-hydrolysis products with biosynthesis. Retained tofieldiae-induced PGP nit1/2/3 plants demonstrated this metabolic connection dispensable for suggests either there alternative between and biosynthesis, or restores independently IG metabolism. We tofieldiae, similar pathogenic microorganisms, triggers immune pathways rely as well salicylic acid ethylene signaling. Analysis IG-deficient myb mutants revealed these metabolites are, indeed, important control planta growth: however, enhanced biomass does not necessarily negatively correlate PGP. deficiency enables more efficient colonization by possibly due MYC2-mediated repression changes constitutive composition roots. [Formula: see text] Copyright © 2021 Author(s). open access article distributed under CC BY-NC-ND 4.0 International license .