Abstract
The antagonistic crosstalk between gibberellic acid (GA) and abscisic acid (ABA) plays a pivotal role in the modulation of seed germination. However, the molecular mechanism of such phytohormone interaction remains largely elusive. Here we show that three Arabidopsis NUCLEAR FACTOR-Y C (NF-YC) homologues NF-YC3, NF-YC4 and NF-YC9 redundantly modulate GA- and ABA-mediated seed germination. These NF-YCs interact with the DELLA protein RGL2, a key repressor of GA signalling. The NF-YC-RGL2 module targets ABI5, a gene encoding a core component of ABA signalling, via specific CCAAT elements and collectively regulates a set of GA- and ABA-responsive genes, thus controlling germination. These results suggest that the NF-YC-RGL2-ABI5 module integrates GA and ABA signalling pathways during seed germination.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Abscisic Acid / metabolism*
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Arabidopsis / genetics
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Arabidopsis / growth & development
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Arabidopsis / metabolism*
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Arabidopsis Proteins / genetics
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Arabidopsis Proteins / metabolism*
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Basic-Leucine Zipper Transcription Factors / metabolism
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CCAAT-Binding Factor / genetics
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CCAAT-Binding Factor / metabolism*
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Gene Expression Regulation, Plant
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Germination*
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Gibberellins / metabolism*
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Transcription Factors / genetics
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Transcription Factors / metabolism*
Substances
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ABI5 protein, Arabidopsis
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Arabidopsis Proteins
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Basic-Leucine Zipper Transcription Factors
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CCAAT-Binding Factor
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Gibberellins
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NF-YC3 protein, Arabidopsis
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NF-YC4 protein, Arabidopsis
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NF-YC9 protein, Arabidopsis
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RGL2 protein, Arabidopsis
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Transcription Factors
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Abscisic Acid
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gibberellic acid