CHOTTO1, a Double AP2 Domain Protein of Arabidopsis thaliana, Regulates Germination and Seedling Growth Under Excess Supply of Glucose and Nitrate
| Autor: | Yuji Kamiya, Jeremy Preston, Sayaka Kitamura, Eiji Nambara, Peter McCourt, Kazutoshi Yamagishi, Hideki Takahashi, Ryoichi Yano, Kiyoshi Tatematsu |
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| Rok vydání: | 2008 |
| Předmět: |
Physiology
Mutant Arabidopsis Germination Plant Science Genes Plant Gene Expression Regulation Plant Botany Cloning Molecular Enhancer Gene Transcription factor Nitrates biology Arabidopsis Proteins Gene Expression Profiling Gene Expression Regulation Developmental food and beverages Cell Biology General Medicine biology.organism_classification Article Addendum Cell biology Glucose Phenotype Seedlings Seedling Imbibition Abscisic Acid Transcription Factors |
| Zdroj: | Plant and Cell Physiology. 50:330-340 |
| ISSN: | 1471-9053 0032-0781 |
| Popis: | Arabidopsis chotto1 (cho1) mutants show resistance to (-)-R-ABA, an ABA analog, during germination and seedling growth. Here, we report cloning and characterization of the CHO1 gene. cho1 mutants showed only subtle resistance to (+)-S-ABA during germination. The cho1 mutation acts as a strong enhancer of the abi5 mutant, whereas the cho1 abi4 double mutant showed ABA resistance similar to the abi4 single mutant. This suggests that CHO1 and ABI4, but not ABI5, act in the same genetic pathway. Map-based cloning revealed that the CHO1 gene encodes a putative transcription factor containing double AP2 domains. The CHO1 gene was expressed predominantly in seed, with the strongest expression in imbibed seed. Induction of CHO1 expression was observed 4 h after seed imbibition and reached a maximum level at 24 h. Induction of CHO1 expression did not occur in the abi4 mutants, indicating that this is an ABI4-dependent process. Microarray experiments showed that a large number of genes involved in primary metabolism and the stress response were up-regulated in the cho1 mutant. Growth of abi4 and cho1 mutant seedlings was resistant to high concentrations of glucose. In addition, growth of cho1 mutant seedlings was partially resistant to excess nitrate (50 mM), as evident from their expanded green cotyledons. However, their growth was normal under moderate nitrate concentrations (< 10 mM). This nitrate response was specific to the cho1 mutants and was not observed in the abi4 mutants. Taken together, our results indicate that CHO1 regulates nutritional responses downstream of ABI4 during germination and seedling growth. |
| Databáze: | OpenAIRE |
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