Integrated analysis of metabolite and transcript profiling data reveals comprehensive reprogramming of metabolic regulatory networks in Arabidopsis to ultraviolet-B light

Abstract

Due to ever increasing environmental deterioration it is likely that influx of UV-B radiation will increase further due to the depletion of stratospheric ozone. Given this fact it becomes essential that we better understand both rapid and adaptive responses of plants to UV-B imposed stress. To understand the mechanism of production of these protective pigments in response to UV-B light, we compare the metabolic responses of wild type Arabidopsis to that of Arabidopsis mutants impaired in flavonoid (TRANSPARENT TESTA [tt]4 and tt5), or sinapoyl-malate (sinapoylglucose accumulator 1 [sng1]) biosynthesis, to a short, 24h or a longer 96h exposure to UV-B imposed stress. Our data reveals that short-term responses occur only at the level of primary metabolites suggesting that these effectively prime the cell in order to facilitate the later production of UV-absorbing secondary metabolites. Transcript profiling was conducted on samples to capture affected responses in transcript levels by irradiation of UV-B. The combined results of these studies are discussed in the context of current models concerning the metabolic response of plants to the stress imposed by excessive UV-B irradiation.