Folic acid orchestrates root development linking cell elongation with auxin response and acts independently of the TARGET OF RAPAMYCIN signaling in Arabidopsis thaliana.

Folic acid is a precursor of tetrahydrofolate (vitamin B9), which is an essential cofactor in most organisms, acting as a carrier for one-carbon units in enzymatic reactions. In this work, we employed pharmacological, genetic and confocal imaging strategies to unravel the signaling mechanism by which folic acid modulates root growth and development. Folic acid supplementation inhibits primary root elongation and induces lateral root formation in a concentration-dependent manner.

Mitogen-Activated Protein Kinase 6 and Ethylene and Auxin Signaling Pathways Are Involved in Arabidopsis Root-System Architecture Alterations by Trichoderma atroviride.

Trichoderma atroviride is a symbiotic fungus that interacts with roots and stimulates plant growth and defense. Here, we show that Arabidopsis seedlings cocultivated with T. atroviride have an altered root architecture and greater biomass compared with axenically grown seedlings.