Project description:In view of the continuous salinization of arable lands world-wide, there is an urgent need to better understand the mechanisms underlying plant responses to salt stress at different stages of their development. We investigated the role of calmodulin (CaM)-binding transcription activator 6 (CAMTA6) under salinity stress during early germination in Arabidopsis. These analyses suggest that ABA signaling is involved in CAMTA6-dependent salt-responsive gene expression, consistent with the ABA hyper-tolerance phenotype and the lack of HKT1 response to ABA and NaCl in the camta6 mutants.
Project description:To understand the role of cytokinins (CKs) in salt stress response, we have employed transcriptional profiling of the CK-deficient mutant, ipt1,3,5,7 and wild type plant, Col-0 under high salinity and control conditions to identify genes differentially expressed in ipt1,3,5,7 under salt stress and control conditions. Agilent's Whole Arabidopsis Gene Expression Microarray (G2519F, V4, 4x44K) was used.
Project description:Transcriptional profiling of Col4WT and WRKY15 overexpressor (WRKY15OE) plants, grown under controlled and mild salt stress conditions in order to identify molecular mechanisms underlying the increased salt stress sensitivity of WRKY15OE plants. Two genotypes x two conditions experiment, including Arabidopsis Col4WT and WRKY15OE plants grown on half-strength MS plant medium supplemented with 0 or 50 mM NaCl. Three biological replicates. Each sample was hybridized to one GenechipM-BM-. Arabidopsis Tiling 1.0R array.
Project description:To understand affected genes by HDA19 and HDA5/14/15/18 under salinity stress conditions, hda19 and hda5/14/15/18 mutants and control (Col-0) plants were analyzed under normal and salinity stress conditions using Arabidopsis custom microarrays (GEO array platform: GPL19830).
Project description:To identify novel miRNA and NAT-siRNAs that are associated with salt and cold stresses in Arabidopsis, we generated small RNA sequences from Arabidopsis plants under salt and cold stress treatments.
Project description:To identify novel miRNA and NAT-siRNAs that are associated with salt and cold stresses in Arabidopsis, we generated small RNA sequences from Arabidopsis plants under salt and cold stress treatments. Sequencing of small RNAs in Arabidopsis under salt, and cold stress conditions.
Project description:To understand the effect of HDA19 deficiency in hda5/14/15/18 (quad) under salinity stress conditions, hda19, quad, hda5/14/15/18/19 (quint) mutants and control (Col-0) plants were analyzed under normal and salinity stress conditions using Arabidopsis custom microarrays (GEO array platform: GPL22706).
Project description:Post-translational modifications (PTMs) of proteins play important roles in the acclimation of plants to environmental stress. Lysine acetylation is a dynamic and reversible PTM, which can be removed by histone deacetylases. Here we investigated the role of lysine acetylation in the response of Arabidopsis leaves to one week of salt stress. A quantitative mass spectrometry analysis revealed an increase in lysine acetylation of several proteins from cytosol and plastids, which was accompanied by an altered HDAC activity in the salt-treated leaves. While activities of HDA14 and HDA15 were decreased upon salt stress, HDA5 showed a mild and HDA19 a strongly increased activity. Since HDA5 is a cytosolic-nuclear enzyme from the class II histone deacetylase family with yet unknown protein substrates, we performed a lysine acetylome analysis on hda5 mutants and characterized its substrate proteins. Next to histone H2B, the salt stress responsive transcription factor GT2L and the dehydration-related protein ERD7 were identified as HDA5 substrates. In addition, in protein-protein interaction studies HDA18 was discovered, among other interacting proteins, to work in a complex together with HDA5. Altogether this study revealed the substrate proteins of HDA5 and identified new lysine acetylation sites which are hyperacetylated upon salt stress. The identification of the specific histone deacetylase substrate proteins, apart from histones, will be important to unravel the acclimation response of Arabidopsis to salt stress and their role in plant physiology.
Project description:<p>Cytokinin (CK) in plants regulates both developmental processes and adaptation to environmental stress. <em>Arabidopsis histidine phosphotransfer ahp2,3,5</em> and type-B<em> response regulator arr1,10,12</em> triple mutants are almost completely defective in CK signaling, and the <em>ahp2,3,5</em> mutant was reported to be salt tolerant. Here, we demonstrate that the <em>arr1,10,12</em> mutant is also more tolerant to salt stress than wild-type plants. A comprehensive metabolite profiling coupled with transcriptome analysis of the<em> ahp2,3,5</em> and <em>arr1,10,12</em> mutants was conducted to elucidate the salt tolerance mechanisms mediated by CK signaling. Numerous primary (e.g., sugars, amino acids and lipids) and secondary (e.g., flavonoids and sterols) metabolites accumulated in these mutants under both non-saline and saline conditions, suggesting that both pre- and post-stress accumulation of stress-related metabolites contribute to improved salt tolerance in CK-signaling mutants. Specifically, the level of oligosaccharides, amino acids [e.g., proline and gamma-aminobutyric acid], anthocyanins, sterols, and unsaturated triacyglycerols, were higher in the mutant plants than in wild-type plants. Notably, the reprograming of flavonoid and lipid pools was highly coordinated and concomitant with changes in transcriptional levels, indicating that these metabolic pathways are transcriptionally regulated by CK signaling. The discovery of the regulatory role of CK signaling on membrane lipid remodelling provides a greater understanding of CK-mediated salt tolerance in plants. This knowledge will contribute to the development of salt-tolerant crops with the ability to withstand salinity as a key driver to ensure global food security in the era of climate change.</p>