Project description:In order to investigate the physiological and biochemical characteristics and molecular mechanisms during the leaf colour change of Acer rubrum L, this study used Acer rubrum L. 'Autumn Blaze' cuttings as material and analysed the transcriptome and miRNAs of Acer rubrum L leaves under different light and temperature treatments. The transcriptome and miRNAs of Acer rubrum L leaves were analysed under different light and temperature treatments, and miRNA-mRNA association analysis was performed for the differentially expressed mRNAs and miRNAs.
Project description:We performed RNA-Seq technology for quantification of differential expression of cacao cell suspensions under light/dark conditions. By obtaining over 15 millions of reads per sample, we cuantified the differential gene expression in structural, regulatory and light signaling genes associated with flavonoid biosynthesis. Our results indicated that light treatments can effectively regulate flavonoid profiles, shifting catechin - epicatechin ratios, in particular as a response to switching from white to blue light. The results demonstrated that HY5, MYB12, ANR and LAR were differentially regulated under light/dark conditions and could be targeted by overexpression aiming to improve catechin synthesis in cell cultures. Additionally, co-expression analyses of late flavonoid biosynthetic genes ANS, ANR and LAR showed a larger number of shared partners in the dark compared to selective partners in white-blue treatment. In conclusion, our RNA-Seq analysis of cacao cells cultured under different light conditions provides a platform to dissect key aspects into the genetic regulatory network of flavonoids. These light-responsive candidate genes can be used further to modulate the flavonoid production in in vitro systems with value-added characteristics.
Project description:We investigated the transcriptional response of cand. Pelagibacter ubique cultures to light and dark when grown under carbon replete and deplete conditions. Results: During exponential phase, few genes were differentially transcribed between light:dark growth conditions. In stationary phase, a high proportion (9.7%) of coding sequences were found differentially expressed between treatments; 4.7% being up-regulated in the light (n=64) and 4.9% being up-regulated in the dark (n=67). Several components of the oxidative phosphorylation pathway were up-regulated in the dark, supporting physiological data showing higher respiration rates in darkness than in the light under starvation conditions. We also observed up-regulation of a proton translocating pyrophosphate synthase (SAR11_1040), which may be an additional energy production mechanism utilized by SAR11 cells in the dark. Finally, we noted the up-regulation of pili formation genes in the array data, consistent with the observation of pili in dark grown cells via electron microscopy.
Project description:Genome wide rhythmic transcription under light/dark cycles is associated with sequential transcription of specific biological processes genes in Ostreococcus tauri. Transcriptional profiling of Ostreococcus tauri under light/dark cycles. In order to identify genes with a diurnal rhythm, cells entrained under 12:12 light/dark cycles were sampled every 3 hours for 27 hours with two overlapping time points at Time 9 (Light ON at Time 9; Light OFF at Time 21) in 3 independent experiments.
Project description:Green plants are more robust to hydrogen peroxide (H2O2) stress and contain high endogeneous H2O2 levels which is generated during photorespiration and photosynthesis. Therefore, exgeneous H2O2 application mostly impose oxidative stress. To reduce endogenous H2O2 background, we adopted a strategy which is to grow Arabidopsis seedlings in the dark to eliminate light-induced H2O2 production, thus to reduce the endogenous H2O2 level. Exogenous H2O2 was then applied to induce transcriptome changes. Global gene expression is studied and compared between samples collected under 7d dark, 7d H2O2 treatment under dark and 7d light conditions.