title: Metabolomic and physiological responses reveal multi-phasic acclimation of Arabidopsis thaliana to chronic UV radiation.
abstract: Biochemical changes in vivo and pathway interactions were investigated using integrated physiological and metabolic responses of Arabidopsis thaliana L. to ultraviolet (UV) radiation (280-400 nm) at 9.96 kJ m(-2) d(-1) over the entire life cycle from seed to seed (8 weeks). Columbia-0 (Col-0) and a UV-B sensitive accession (fah-1) showed significant (P < 0.001) reductions in leaf growth after 6 weeks. Col-0 recovered growth after 8 weeks, with recovery corresponding to a switch from production of phenylpropanoids to flavonoids. fah-1 failed to recover, indicating that sinapate production is an essential component of recovery. Epidermal features show that UV radiation caused significant (P < 0.001) increases in trichome density, which may act as a structural defence response. Stomatal indices showed a significant (P < 0.0001) reduction in Col-0 and a significant (P < 0.001) increase in fah-1. Epidermal cell density was significantly increased under UV radiation on the abaxial leaf surface, suggesting that that a fully functioning phenylpropanoid pathway is a requirement for cell expansion and leaf development. Despite wild-type acclimation, the costs of adaptation lead to reduced plant fitness by decreasing flower numbers and total seed biomass. A multi-phasic acclimation to UV radiation and the induction of specific metabolites link stress-induced biochemical responses to enhanced acclimation.
authors: Department of Animal and Plant Sciences, University of Sheffield, Sheffield, UK. j.a.lake@sheffield.ac.uk
authors: Janice A
authors: JA
authors: Lake
authors: Katie J
authors: KJ
authors: Field
authors: Matthew P
authors: MP
authors: Davey
authors: David J
authors: DJ
authors: Beerling
authors: Barry H
authors: BH
authors: Lomax
mesh_terms: D000064:Acclimatization; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism / Q000502:physiology* / Q000528:radiation effects*; D002247:Carbon Isotopes / Q000032:analysis; D005419:Flavonoids / Q000096:biosynthesis; D035264:Flowers / Q000254:growth & development / Q000528:radiation effects; D055432:Metabolomics; D019441:Plant Epidermis / Q000528:radiation effects; D018515:Plant Leaves / Q000254:growth & development / Q000528:radiation effects; D012639:Seeds / Q000254:growth & development / Q000528:radiation effects; D014466:Ultraviolet Rays
chemical_list: D002247:Carbon Isotopes; D005419:Flavonoids