A Stress-Responsive Caleosin-Like Protein, AtCLO4, Acts as a Negative Regulator of ABA Responses in Arabidopsis
| Autor: | Jeong Sheop Shin, Kwang Wook Jung, Ji Ung Jeung, Yun Young Kim, Kyoung Shin Yoo |
|---|---|
| Rok vydání: | 2011 |
| Předmět: |
DNA
Bacterial Physiology Drought tolerance Mutant Arabidopsis Germination Plant Science Sodium Chloride Genes Plant Gene Expression Regulation Plant Stress Physiological Guard cell Botany medicine Arabidopsis thaliana Mannitol Promoter Regions Genetic Plant Proteins Regulator gene biology Arabidopsis Proteins Chemistry Calcium-Binding Proteins fungi Wild type food and beverages Cell Biology General Medicine Plants Genetically Modified biology.organism_classification Adaptation Physiological Droughts Cell biology Mutagenesis Insertional Organ Specificity Gene Knockdown Techniques Mutation Plant Stomata Seeds Plant Vascular Bundle Abscisic Acid Protein Binding Signal Transduction Subcellular Fractions medicine.drug |
| Zdroj: | Plant and Cell Physiology. 52:874-884 |
| ISSN: | 1471-9053 0032-0781 |
| DOI: | 10.1093/pcp/pcr039 |
| Popis: | Caleosins or related sequences have been found in a wide range of higher plants. In Arabidopsis, seed-specific caleosins are viewed as oil-body (OB)-associated proteins that possess Ca(2+)-dependent peroxygenase activity and are involved in processes of lipid degradation. Recent experimental evidence suggests that one of the Arabidopsis non-seed caleosins, AtCLO3, is involved in controlling stomatal aperture during the drought response; the roles of the other caleosin-like proteins in Arabidopsis remain largely uncharacterized. We have demonstrated that a novel stress-responsive and OB-associated Ca(2+)-binding caleosin-like protein, AtCLO4, is expressed in non-seed tissues of Arabidopsis, including guard cells, and down-regulated following exposure to exogenous ABA and salt stress. At the seed germination stage, a loss-of-function mutant (atclo4) was hypersensitive to ABA, salt and mannitol stresses, whereas AtCLO4-overexpressing (Ox) lines were more hyposensitive to those stresses than the wild type. In adult stage, atclo4 mutant and AtCLO4-Ox plants showed enhanced and decreased drought tolerance, respectively. Following exposure to exogenous ABA, the expression of key ABA-dependent regulatory genes, such as ABF3 and ABF4, was up-regulated in the atclo4 mutant, while it was down-regulated in AtCLO4-Ox lines. Based on these results, we propose that the OB-associated Ca(2+)-binding AtCLO4 protein acts as a negative regulator of ABA responses in Arabidopsis. |
| Databáze: | OpenAIRE |
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