Project description:We analysed the effect of cold priming on cold and high light regulation of gene expression. 5 days after the first cold treatment the primary stress response was widely reset. Then, a second (triggering) cold stimulus (24 h 4 °C) and a triggering high-light stimulus (2 h 800 µmol quanta m-2 s-1), which regulate many stress responsive genes in the same direction in naïve plants, caused widely specific and even inverse regulation of priming-responsive genes.
Project description:rs09-04_plc_2 - edelfosine and wortmannin effect at 22°c and 4°c - Is there an overlap between PI4-kinase and phospholipase C signaling in cold response ? - Experiments were carried out with Columbia suspension cells. Cells were treated or not with edelfosine (PLC inhibitor) or wortmannin (PI4-kinase inhibitor). These agents were added 15 min before cold stress. ARN were extracted 4h after stress. Controls were made at 22°C. Keywords: treated vs untreated comparison 11 dye-swap - CATMA arrays
Project description:We analysed the effect of a short 24 hours cold exposure (priming-stimulus) on gene regulation upon the first two hours of a second cold (4°C) stimulus (cold-triggering) and upon the first two hours of excess light exposure (800 µmol photons m-2 s-1, light triggering). The first and the second stress treatment was seperated by 5 days long lag-phase, which is long enough to reset most of the primary stress response. Several early light and early cold responsive genes showed however a altered transcript abundance in plants, which received five days befor the cold priming stimulus. Espicially JA responsive genes showed a common priming regulation within the cold and light exposure.
Project description:Cold stress is one of the most severe environmental conditions which cause huge losses in crop production worldwide. We identified an essential regulator of cold-responsive genes and used the Affymetrix whole-genome arrays to define downstream targets of this important protein. We used the microarrays to reveal the effect of rcf1-1 mutation on global gene expression with or without cold stress at 4°C. A set of genes differentially expressed in rcf1-1 with or without cold stress are identified.
Project description:rs09-04_plc_2 - edelfosine and wortmannin effect at 22°c and 4°c - Is there an overlap between PI4-kinase and phospholipase C signaling in cold response ? - Experiments were carried out with Columbia suspension cells. Cells were treated or not with edelfosine (PLC inhibitor) or wortmannin (PI4-kinase inhibitor). These agents were added 15 min before cold stress. ARN were extracted 4h after stress. Controls were made at 22°C. Keywords: treated vs untreated comparison
Project description:The study aims at determining the genes that are induced or repressed by cold in the suspension cells. It also aims at monitoring the effect of inhibitors of PLC (U73122 vs. U73343) and PLD (ethanol vs. tertiary butanol) on cold response at the transcription level. To answer this question we chose a pharmacological approach. We decided to use molecules that are going to inhibit PLC or PLD. For PLC we use U73122 and its inactive analog as a control; for PLD we used a primary alcohol (ethanol) and a tertiary alcohol (tert-butanol) as a control. We therefore extracted RNA after the following treatments:<br> 4 °C<br> 22 °C<br> 4 °C + 0.9% primary-ethanol<br> 4 °C + 0.9% tertiary-butanol<br> 4 °C + 60 micromolaire U73122<br> 4 °C + 60 micromolaire U73343<br> The exposure at 4 °C was 4 hours.
Project description:To understand the gene network that controls plant tolerance to cold stress, we carried out a near full genome transcript expression profiling in Arabidopsis using Affymetrix GeneChips that contain approximately 24,000 genes. For microarray analysis, Arabidopsis seedlings were cold treated at 0 C for 0 h, 3 h, 6 h, and 24 h. A total of 939 genes were statistically determined to be cold-regulated with 655 being up-regulated and 284 down-regulated. A large number of the early cold-responsive genes encode transcription factors that likely control late-responsive genes, which implies a multitude of transcriptional cascades. In addition, many genes involved in post-transcriptional and chromatin level regulation were also cold regulated suggesting their involvement in cold responsive gene regulation. A number of genes important for the biosynthesis or signaling of plant hormones, such as abscisic acid, gibberellic acid and auxin, are regulated by cold stress, which is of potential importance in coordinating cold tolerance with growth and development. We compared the cold-responsive transcriptomes of wild type and ice1, a mutant defective in an upstream transcription factor required for chilling and freezing tolerance. The transcript levels of many cold-responsive genes were altered in the ice1 mutant not only during cold stress conditions, but also before cold treatments. Our study provides a global picture of the Arabidopsis cold-responsive transcriptome and its control by ICE1, and thus will be valuable for understanding gene regulation under cold stress and the molecular mechanisms of cold tolerance. Keywords: Cold Stress response