title: Metabolomics reveals comprehensive reprogramming involving two independent metabolic responses of Arabidopsis to UV-B light.
abstract: Because of ever-increasing environmental deterioration it is likely that the influx of UV-B radiation (280-320 nm) will increase as a result of the depletion of stratospheric ozone. Given this fact it is essential that we better understand both the rapid and the adaptive responses of plants to UV-B stress. Here, we compare the metabolic responses of wild-type Arabidopsis with that of mutants impaired in flavonoid (transparent testa 4, tt4; transparent testa 5, tt5) or sinapoyl-malate (sinapoylglucose accumulator 1, sng1) biosynthesis, exposed to a short 24-h or a longer 96-h exposure to this photo-oxidative stress. In control experiments we subjected the genotypes to long-day conditions as well as to 24- and 96-h treatments of continuous light. Following these treatments we evaluated the dynamic response of metabolites including flavonoids, sinapoyl-malate precursors and ascorbate, which are well known to play a role in cellular protection from UV-B stress, as well as a broader range of primary metabolites, in an attempt to more fully comprehend the metabolic shift following the cellular perception of this stress. Our data reveals that short-term responses occur only at the level of primary metabolites, suggesting that these effectively prime the cell to facilitate the later production of UV-B-absorbing secondary metabolites. The combined results of these studies together with transcript profiles using samples irradiated by 24-h UV-B light are discussed in the context of current models concerning the metabolic response of plants to the stress imposed by excessive UV-B irradiation.
authors.affiliation: RIKEN Plant Science Center, Yokohama, Kanagawa, Japan.
authors.forename: Miyako
authors.initials: M
authors.lastname: Kusano
authors.forename: Takayuki
authors.initials: T
authors.lastname: Tohge
authors.forename: Atsushi
authors.initials: A
authors.lastname: Fukushima
authors.forename: Makoto
authors.initials: M
authors.lastname: Kobayashi
authors.forename: Naomi
authors.initials: N
authors.lastname: Hayashi
authors.forename: Hitomi
authors.initials: H
authors.lastname: Otsuki
authors.forename: Youichi
authors.initials: Y
authors.lastname: Kondou
authors.forename: Hiroto
authors.initials: H
authors.lastname: Goto
authors.forename: Mika
authors.initials: M
authors.lastname: Kawashima
authors.forename: Fumio
authors.initials: F
authors.lastname: Matsuda
authors.forename: Rie
authors.initials: R
authors.lastname: Niida
authors.forename: Minami
authors.initials: M
authors.lastname: Matsui
authors.forename: Kazuki
authors.initials: K
authors.lastname: Saito
authors.forename: Alisdair R
authors.initials: AR
authors.lastname: Fernie
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism* / Q000528:radiation effects*; D005838:Genotype; D055442:Metabolome; D055432:Metabolomics; D009154:Mutation; D020411:Oligonucleotide Array Sequence Analysis; D018384:Oxidative Stress; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014466:Ultraviolet Rays