Project description:Transcription profiling of Arabidopsis plants grown in high versus low Cu2+ concentration. Keywords: Stress response Three replicates for each sample category (Arabidopsis Col0 grown either in high or low Cu2+) were generated, and compared directly to each other, in a non-paired direct comparisson. Two technical replicas from each biological replica were carried out.
Project description:Arabidopsis thaliana is a glycophyte with a low salt tolerance, while Eutrema is a halophyte with a very high salt tolerance. To elucidate the transcriptional basis of this difference, we performed hydroponis culture experiments where we grew plants under control conditions (25 mM NaCl) or under salt stress (200 mM NaCl for both species, 500 mM for Eutrema). Salt concentration was increased for the stress treatments by increments of 50 mM per day (25 mM on the first day). Plants were grown at the final NaCl concentration for an additional week, when rosettes were harvested for RNA isolation.Expression patterns were compared between treatments and between species.
Project description:Arabidopsis Col-0 seeds were germinated and grown for two weeks on Arabidopsis thaliana salt media (ATS, control) or ATS media supplemented 50, 75, 100 or 125 mM NaCl that imposes both an ionic and osmotic stress; or ATS media supplemented with iso-osmolar concentrations of sorbitol (100, 150, 200 or 250 mM) that imposes only an osmotic stress. The aim of the study was to identify genes involved in plant growth and adaptation to ionic stress compared to genes involved in growth and adaptation to osmotic stress conditions. To do this we identified lists of genes that are differentially expressed in plants grown in NaCl (A) and lists of genes differentially expressed in plants grown in sorbitol (B). We then compared these lists to find ionic/salt-specific genes that are only expressed in plants grown in NaCl and not in plants grown in sorbitol; and osmotic genes that are expressed both in plants grown in NaCl and in plants grown in sorbitol. Associated publication: Cackett et al. (2022) Salt-specific gene expression reveals elevated auxin levels in Arabidopsis thaliana plants grown under saline conditions, DOI: 10.3389/fpls.2022.804716
Project description:Arabidopsis thaliana is a glycophyte with a low salt tolerance, while Eutrema is a halophyte with a very high salt tolerance. To elucidate the transcriptional basis of this difference, we performed hydroponis culture experiments where we grew plants under control conditions (25 mM NaCl) or under salt stress (200 mM NaCl for both species, 500 mM for Eutrema). Salt concentration was increased for the stress treatments by increments of 50 mM per day (25 mM on the first day). Plants were grown at the final NaCl concentration for an additional week, when rosettes were harvested for RNA isolation.Expression patterns were compared between treatments and between species. In total, 15 samples were hybridized. They were derived from three independent biological experiments (replicate_1 to replicate_3). Controlds were grown at 25 mM NaCl, salt stressed plants at either 200 mM NaCl or 500 mM NaCl.
Project description:Plants in temperate regions have evolved mechanisms to survive sudden temperature drops. Previous reports have indicated that the cold acclimation mechanism is light-dependent and does not fully operate under a low light intensity. In these studies, plants were grown under a long-day photoperiod and were more sensitive to freezing stress. However, winter annuals like Arabidopsis thaliana Col-0 germinate in the fall, overwinter as rosettes, and therefore must acclimate under short photoperiods and low irradiance. The role of light intensity was analysed in plants grown under a short-day photoperiod at the growth stage 1.14. Plants were acclimated at 4 °C for seven days under 100 and 20 μmol m-2s-1 PPFD for control and limited-light conditions, respectively. All cold acclimated plants accumulated molecular markers reportedly associated with acquired freezing tolerance, including proline, sucrose, CBFs, and COR gene protein products dehydrins and low-temperature-responsive proteins LTIs. Observed changes indicated that low PPFD did not inhibit the cold acclimation process, and the freezing stress experiment confirmed similar survival rates. The molecular analysis found distinct PPFD-specific adaptation mechanisms that were manifested in contrasting content of anthocyanins, cytokinin conjugates, abundances of proteins forming photosystems, and enzymes of protein, energy, and ROS metabolism pathways. Finally, this study led to the identification of putative proteins and metabolite markers correlating with susceptibility to freezing stress of non-acclimated plants grown under low PPFD. Our data show that Arabidopsis plants grown under short-day photoperiod can be fully cold-acclimated under limited light conditions, employing standard and PPFD-specific pathways.
Project description:Cold stress is one of the major limiting factors for global crop production. For survival at low temperature, plants need to sense the temperature changes in the surrounding environment. How plants sense and respond to the earliest drop in temperature is still not clearly understood. The plasma membrane and its adjacent extracellular and cytoplasmic sites are the first checkpoints for sensing temperature changes and subsequent events such as signal generation and solute transport. To understand how plants respond to early cold exposure, we have used a mass spectrometry-based phosphoproteomic method to study temporal changes in protein phosphorylation events in Arabidopsis membranes during 5 to 60 min of cold exposure.
Phosphoproteomic analysis was carried out by using the following process. Arabidopsis membrane fraction was extracted from leaves. Trypsin digestion and phosphopeptide enrichment by HAMMOC method were performed, then purified peptide sample was analyzed by TripleTOF5600 (AB-SCIEX).
Project description:We used N-(1-naphthyl) phthalamic acid (NPA)-induced vascular overgrowth in Arabidopsis leaves to look for differential up-regulation of genes in NPA-treated tissues that may be involved in vascular differentiation. Arabidopsis thaliana Col-0 plants were grown for approximately 2 weeks on solid ATS medium (1) containing a final concentration of 10 um NPA (dissolved in DMSO) or an equivalent volume of DMSO (control). At this stage plants had approximately 6 rosette leaves. RNA was prepared from entire shoot tissues of control (DMSO) or NPA-treated plants.(1) Lincoln et al., 1990. Plant Cell 2: 1071-1080.
Project description:To develop a screening system for plant activators, which are novel substances that protect plants by enhancing their inherent disease-resistance mechanisms, we performed analysis using an Arabidopsis microarray consisting of 1200 full-length cDNA clones representing putative defense-related and regulatory genes. A total of 1.2K potential biotic and abiotic stress-related genes were selected from the genes covered by the Arabidopsis 7K array (RIKEN, Japan) and Arabidopsis oligo microarray (Agilent Technologies, USA) for this study. Arabidopsis wild-type plants (ecotype Columbia; Col-0) were grown in soil for 28 days in a growth chamber at 22。C under a 12-h light/ 12-h dark cycle. Arabidopsis plants were applied a foliar spray with 5 mM SA, 0.1 mM MeJA, 1 mM ethephon, 0.5 mM BTH, 10 mM BABA and 1 mM INA. Benzo(1,2,3)thiadiazole-7-carbothioic acid S-methyl ester and 2,6-dichloroisonicotinic acid activated plant defense responses via the salicylic acid (SA)-dependent signaling pathway, and _-aminobutyric acid triggered a primed state in the plant that enables more efficient activation of the SA-, jasmonic acid- and ethylene-signaling pathway. These results suggest that this novel system can be used to screen for candidate plant activators. Keywords: time course, dose response