title: Auxin response under osmotic stress.
abstract: The phytohormone auxin (indole-3-acetic acid, IAA) is a small organic molecule that coordinates many of the key processes in plant development and adaptive growth. Plants regulate the auxin response pathways at multiple levels including biosynthesis, metabolism, transport and perception. One of the most striking aspects of plant plasticity is the modulation of development in response to changing growth environments. In this review, we explore recent findings correlating auxin response-dependent growth and development with osmotic stresses. Studies of water deficit, dehydration, salt, and other osmotic stresses point towards direct and indirect molecular perturbations in the auxin pathway. Osmotic stress stimuli modulate auxin responses by affecting auxin biosynthesis (YUC, TAA1), transport (PIN), perception (TIR/AFB, Aux/IAA), and inactivation/conjugation (GH3, miR167, IAR3) to coordinate growth and patterning. In turn, stress-modulated auxin gradients drive physiological and developmental mechanisms such as stomata aperture, aquaporin and lateral root positioning. We conclude by arguing that auxin-mediated growth inhibition under abiotic stress conditions is one of the developmental and physiological strategies to acclimate to the changing environment.
authors.affiliation: Department of Molecular Biology and Ecology of Plants, Tel Aviv University, 69978, Tel Aviv, Israel.
authors.forename: Victoria
authors.initials: V
authors.lastname: Naser
authors.affiliation: Department of Molecular Biology and Ecology of Plants, Tel Aviv University, 69978, Tel Aviv, Israel. eilonsh@post.tau.ac.il.
authors.forename: Eilon
authors.initials: E
authors.lastname: Shani
mesh_terms: D001692:Biological Transport / Q000187:drug effects; D007210:Indoleacetic Acids / Q000494:pharmacology*; D008954:Models, Biological; D009997:Osmotic Pressure; D013312:Stress, Physiological / Q000187:drug effects
chemical_list: D007210:Indoleacetic Acids
keywords: Abiotic stress; Auxin biosynthesis; Auxin metabolism; Auxin perception; Auxin response; Auxin transport; Drought stress; Hormone-stress crosstalk; Osmotic stress