Arabidopsis SAG protein containing the MDN1 domain participates in seed germination and seedling development by negatively regulating ABI3 and ABI5
| Autor: | Chengchao Zheng, Changai Wu, Jinguang Huang, Dan Sun, Jiaming Miao, Guodong Yang, Dongxiao Zhao, Changtian Chen, Yunxue Lei |
|---|---|
| Rok vydání: | 2013 |
| Předmět: |
Physiology
Mutant Arabidopsis seed germination Down-Regulation Gene Expression chemical and pharmacologic phenomena Germination drought Plant Science Sodium Chloride Abscisic acid chemistry.chemical_compound Plant Growth Regulators Gene Expression Regulation Plant parasitic diseases Botany salt Storage protein Arabidopsis thaliana Mannitol chemistry.chemical_classification biology Arabidopsis Proteins AtSAG fungi food and beverages Plants Genetically Modified biology.organism_classification Protein Structure Tertiary Up-Regulation Cell biology body regions MDN1 domain Mutagenesis Insertional Basic-Leucine Zipper Transcription Factors chemistry Seedlings Seedling Seeds Oleosin Research Paper Signal Transduction Transcription Factors |
| Zdroj: | Journal of Experimental Botany |
| ISSN: | 1460-2431 0022-0957 |
| DOI: | 10.1093/jxb/ert343 |
| Popis: | SAG encodes a MDN1 domain containing protein in Arabidopsis. Seeds of a T-DNA insertion line of this gene exhibited hypersensitivity to ABA, mannitol and NaCl during seed germination and early seedling development. SAG was genetically epistatic to ABI3 and ABI5 Three proteins containing a midasin homologue 1 (MDN1) domain from the yeast Solanum chacoense and Arabidopsis thaliana have important functions in yeast survival, seed development, and female gametogenesis. In this study, a novel protein containing the MDN1 domain from Arabidopsis negatively regulated abscisic acid (ABA) signalling during seed germination. Seeds of a T-DNA insertion line of this gene exhibited increased sensitivity to ABA during seed germination and seedling development (named sag). By contrast, seeds with overexpressed AtSAG (OX2) were less sensitive to ABA. The seeds of the sag mutant showed similar sensitivity to high concentrations of mannitol and NaCl during these stages. AtSAG was also highly expressed in germinating seeds. However, ABA-induced AtSAG expression remained almost unchanged. ABA-responsive marker genes, including ABI3, ABI5, Em1, Em6, RD29A, and RAB18, were upregulated in sag mutants but were downregulated in OX2. Genetic analyses indicated that the function of AtSAG in ABA signalling depended on ABI3 and ABI5. The expression of some target genes of ABI3 and ABI5, such as seed storage protein and oleosin genes, was induced higher by ABA in sag mutants than in wild-type germinated seeds, even higher than in abi5 mutants. This finding indicated that other regulators similar to ABI3 or ABI5 played a role during these stages. Taken together, these results indicate that AtSAG is an important negative regulator of ABA signalling during seed germination and seedling development. |
| Databáze: | OpenAIRE |
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