Arabidopsis WRKY6 Transcription Factor Acts as a Positive Regulator of Abscisic Acid Signaling during Seed Germination and Early Seedling Development

Yun Huang; Cui-Zhu Feng; Qing Ye; Wei-Hua Wu; Yi-Fang Chen

doi:10.1371/journal.pgen.1005833

Arabidopsis WRKY6 Transcription Factor Acts as a Positive Regulator of Abscisic Acid Signaling during Seed Germination and Early Seedling Development

PLoS Genet. 2016 Feb 1;12(2):e1005833. doi: 10.1371/journal.pgen.1005833. eCollection 2016 Feb.

Authors

Yun Huang¹, Cui-Zhu Feng¹, Qing Ye¹, Wei-Hua Wu¹, Yi-Fang Chen¹

Affiliation

¹ State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, National Plant Gene Research Centre (Beijing), Beijing, China.

Abstract

The phytohormone abscisic acid (ABA) plays important roles during seed germination and early seedling development. Here, we characterized the function of the Arabidopsis WRKY6 transcription factor in ABA signaling. The transcript of WRKY6 was repressed during seed germination and early seedling development, and induced by exogenous ABA. The wrky6-1 and wrky6-2 mutants were ABA insensitive, whereas WRKY6-overexpressing lines showed ABA-hypersensitive phenotypes during seed germination and early seedling development. The expression of RAV1 was suppressed in the WRKY6-overexpressing lines and elevated in the wrky6 mutants, and the expression of ABI3, ABI4, and ABI5, which was directly down-regulated by RAV1, was enhanced in the WRKY6-overexpressing lines and repressed in the wrky6 mutants. Electrophoretic mobility shift and chromatin immunoprecipitation assays showed that WRKY6 could bind to the RAV1 promoter in vitro and in vivo. Overexpression of RAV1 in WRKY6-overexpressing lines abolished their ABA-hypersensitive phenotypes, and the rav1 wrky6-2 double mutant showed an ABA-hypersensitive phenotype, similar to rav1 mutant. Together, the results demonstrated that the Arabidopsis WRKY6 transcription factor played important roles in ABA signaling by directly down-regulating RAV1 expression.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Abscisic Acid / metabolism*
Abscisic Acid / pharmacology
Arabidopsis / drug effects
Arabidopsis / embryology
Arabidopsis / genetics
Arabidopsis / metabolism*
Arabidopsis Proteins / genetics
Arabidopsis Proteins / metabolism*
Base Sequence
Gene Expression Regulation, Plant / drug effects
Genes, Plant
Germination* / drug effects
Germination* / genetics
Models, Biological
Molecular Sequence Data
Mutation / genetics
Plants, Genetically Modified
Repressor Proteins / metabolism
Seedlings / drug effects
Seedlings / genetics
Seedlings / growth & development*
Seeds / drug effects
Seeds / embryology*
Seeds / genetics
Signal Transduction* / drug effects
Signal Transduction* / genetics
Transcription Factors / genetics
Transcription Factors / metabolism*

Substances

Arabidopsis Proteins
Repressor Proteins
Transcription Factors
WRKY6 protein, Arabidopsis
Abscisic Acid

Grants and funding

This work was supported by grants from the ‘973’ Project (2011CB100305 to YFC; 2012CB114203 to WHW), the National Natural Science Foundation of China (Nos. 30970220 and 31170248 to YFC; Nos. 30380013 and 31121002 to WHW) and the ‘111’ Project (No. B06003). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.