title: UV-A radiation effects on higher plants: Exploring the known unknown.
abstract: Ultraviolet-A radiation (UV-A: 315-400nm) is a component of solar radiation that exerts a wide range of physiological responses in plants. Currently, field attenuation experiments are the most reliable source of information on the effects of UV-A. Common plant responses to UV-A include both inhibitory and stimulatory effects on biomass accumulation and morphology. UV-A effects on biomass accumulation can differ from those on root: shoot ratio, and distinct responses are described for different leaf tissues. Inhibitory and enhancing effects of UV-A on photosynthesis are also analysed, as well as activation of photoprotective responses, including UV-absorbing pigments. UV-A-induced leaf flavonoids are highly compound-specific and species-dependent. Many of the effects on growth and development exerted by UV-A are distinct to those triggered by UV-B and vary considerably in terms of the direction the response takes. Such differences may reflect diverse UV-perception mechanisms with multiple photoreceptors operating in the UV-A range and/or variations in the experimental approaches used. This review highlights a role that various photoreceptors (UVR8, phototropins, phytochromes and cryptochromes) may play in plant responses to UV-A when dose, wavelength and other conditions are taken into account.
authors.affiliation: Environmental Sciences Department, Faculty of Sciences, University of Girona, Campus de Montilivi, C/Maria Aurèlia Capmany I Farnés, 69, E-17003 Girona, Spain. Electronic address: dolors.verdaguer@udg.edu.
authors.forename: Dolors
authors.initials: D
authors.lastname: Verdaguer
authors.affiliation: School of Biological, Earth and Environmental Sciences, University College Cork, Distillery Field, North Mall, Cork, Ireland. Electronic address: M.Jansen@ucc.ie.
authors.forename: Marcel A K
authors.initials: MA
authors.lastname: Jansen
authors.affiliation: Environmental Sciences Department, Faculty of Sciences, University of Girona, Campus de Montilivi, C/Maria Aurèlia Capmany I Farnés, 69, E-17003 Girona, Spain. Electronic address: laura.llorens@udg.edu.
authors.forename: Laura
authors.initials: L
authors.lastname: Llorens
authors.affiliation: Division of Plant Biology, Department of Biosciences, Viikki Plant Science Center, University of Helsinki, FI-00014 Helsinki, Finland. Electronic address: luis.morales@helsinki.fi.
authors.forename: Luis O
authors.initials: LO
authors.lastname: Morales
authors.affiliation: Leibniz-Institute of Vegetable and Ornamental Crops Grossbeeren/Erfurt e.V., Theodor-Echtermeyer-Weg 1, 14979, Grossbeeren, Germany. Electronic address: neugart@igzev.de.
authors.forename: Susanne
authors.initials: S
authors.lastname: Neugart
mesh_terms: D018533:Biomass; D019669:Embryophyta / Q000254:growth & development / Q000378:metabolism / Q000528:radiation effects*; D005419:Flavonoids / Q000378:metabolism; D055519:Photoreceptors, Plant / Q000378:metabolism / Q000528:radiation effects*; D010788:Photosynthesis; D010860:Pigments, Biological / Q000378:metabolism; D018514:Plant Structures / Q000254:growth & development / Q000378:metabolism / Q000528:radiation effects*; D014466:Ultraviolet Rays
chemical_list: D005419:Flavonoids; D055519:Photoreceptors, Plant; D010860:Pigments, Biological
keywords: Morphology; Phenolics; Photodamage; Photosynthesis; Plant biomass; Ultraviolet-A