Ultraviolet-B-induced Sstomatal closure in arabidopsis is regulated by the UV RESISTANCE LOCUS8 photoreceptor in a nitric oxide-dependent mechanism

Tossi, V., Lamattina, L., Jenkins, G. I. and Cassia, R. O. (2014) Ultraviolet-B-induced Sstomatal closure in arabidopsis is regulated by the UV RESISTANCE LOCUS8 photoreceptor in a nitric oxide-dependent mechanism. Plant Physiology, 164(4), pp. 2220-2230. (doi: 10.1104/pp.113.231753)

Abstract

PHOTOMORPHOGENIC1, the ELONGATED HYPOCOTYL5 (HY5) transcription factor, and the closely related HY5 HOMOLOG. Some UV-B responses mediated by UVR8 are also regulated by nitric oxide (NO), a bioactive molecule that orchestrates a wide range of processes in plants. In this study, we investigated the participation of the UVR8 pathway and its interaction with NO in UV-B-induced stomatal movements in Arabidopsis (Arabidopsis thaliana). Stomata in abaxial epidermal strips of Arabidopsis ecotype Landsberg erecta closed in response to increasing UV-B fluence rates, with maximal closure after 3-h exposure to 5.46 μmol m–2 s–1 UV-B. Both hydrogen peroxide (H2O2) and NO increased in response to UV-B, and stomatal closure was maintained by NO up to 24 h after the beginning of exposure. Stomata of plants expressing bacterial NO dioxygenase, which prevents NO accumulation, did not close in response to UV-B, although H2O2 still increased. When the uvr8-1 null mutant was exposed to UV-B, stomata remained open, irrespective of the fluence rate. Neither NO nor H2O2 increased in stomata of the uvr8-1 mutant. However, the NO donor S-nitrosoglutathione induced closure of uvr8-1 stomata to the same extent as in the wild type. Experiments with mutants in UVR8 signaling components implicated CONSTITUTIVELY PHOTOMORPHOGENIC1, HY5, and HY5 HOMOLOG in UV-B-induced stomatal closure. This research provides evidence that the UVR8 pathway regulates stomatal closure by a mechanism involving both H2O2 and NO generation in response to UV-B exposure.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Jenkins, Professor Gareth
• Authors: Tossi, V., Lamattina, L., Jenkins, G. I., and Cassia, R. O.
• College/School: College of Medical Veterinary and Life Sciences > School of Molecular Biosciences
• Journal Name: Plant Physiology
• Publisher: American Society of Plant Biologists
• ISSN: 0032-0889
• ISSN (Online): 1532-2548