Project description:The purpose of this experiment was to identify genes responding differently to a 24 h low red to far red ratio (R:FR) treatment in plants grown at 16 and 22 degrees Keywords: Light treatment
Project description:The purpose of this experiment was to identify genes responding differently to a 24 h low red to far red ratio (R:FR) treatment in plants grown at 16 and 22 degrees Experiment Overall Design: Microarrays were used as a gene discovery tool to identify genes showing differential regulation by low R:FR at 2 growth temperatures. Plants subject to a 24 h low R:FR light treatment were compared with control plants maintained in high R:FR. This experiment was carried out at two growth temperatures, 16oC and 22oC.
Project description:The goal of this work was to investigate oxidative stress responses of Arabidopsis to low red to far-red ratios of light as a signal of competition using a biological weedy and an artificial source of far-red light. More specifically, elucidation of the signaling role of singlet oxygen in Arabidopsis under low red-to far-red light environments was the major objective of this work. Oxidative stress responses of Arabidopsis to low red (R) to far-red (FR) signals (R:FR ≈ 0.3), generated by a biological weedy and an artificial source of FR light, were compared with a weed-free control (R:FR ≈1.4). In the low R:FR treatments, induction of the shade avoidance responses coincided with increased singlet oxygen (1O2) production and decreased level of superoxide and superoxide dismutase activity. Although the increase of 1O2 was not due to protochlorophyllide accumulation and did not result in cell death, treatments with the 1O2 generator 5-aminolevulinic acid increased sensitivity to cell death. Transcriptome responses minimally resembled those reported in four Arabidopsis 1O2 generating systems such that only few genes (6 out of 1931) were consistently up-regulated supporting the specificity of 1O2 signaling. Moreover, suppressors of jasmonate accumulation, including the 1O2-responsive amidohydrolase ILL6, the sulfotransferase ST2a, which are involved in prioritization of elongation growth versus defense were consistently up-regulated. Our data support a model in which photoreceptors connect low R:FR light cues to the JA signaling pathway. Repression of bioactive JAs via the amidohydrolase ILL6, and sulfotransferase ST2a may promote the shade avoidance (versus defense) and 1O2 acclimation (versus cell death) responses to competition cues.
Project description:Hypocotyl and cotyledon transcriptome in Arabidopsis thaliana treated with 1 ppm ethylene and shade (low PAR, low blue and low R:FR)
Project description:Aim of the experiment is the identification of regulatory genes rapidly induced by low R/FR and still up-regulated after prolonged exposure to FR-rich light. To this end, gene expression changes were analysed in Arabidopsis thaliana seedlings after exposure to low R/FR light for a short and a long period of time. The experiment was designed to enable comparison between treated and untreated Arabidopsis seedlings.