The WRKY6 Transcription Factor ModulatesPHOSPHATE1Expression in Response to Low Pi Stress inArabidopsis
Open Access
- 1 November 2009
- journal article
- Published by Oxford University Press (OUP) in Plant Cell
- Vol. 21 (11), 3554-3566
- https://doi.org/10.1105/tpc.108.064980
Abstract
Arabidopsis thaliana WRKY family comprises 74 members and some of them are involved in plant responses to biotic and abiotic stresses. This study demonstrated that WRKY6 is involved in Arabidopsis responses to low-Pi stress through regulating PHOSPHATE1 (PHO1) expression. WRKY6 overexpression lines, similar to the pho1 mutant, were more sensitive to low Pi stress and had lower Pi contents in shoots compared with wild-type seedlings and the wrky6-1 mutant. Immunoprecipitation assays demonstrated that WRKY6 can bind to two W-boxes of the PHO1 promoter. RNA gel blot and β-glucuronidase activity assays showed that PHO1 expression was repressed in WRKY6-overexpressing lines and enhanced in the wrky6-1 mutant. Low Pi treatment reduced WRKY6 binding to the PHO1 promoter, which indicates that PHO1 regulation by WRKY6 is Pi dependent and that low Pi treatment may release inhibition of PHO1 expression. Protein gel blot analysis showed that the decrease in WRKY6 protein induced by low Pi treatment was inhibited by a 26S proteosome inhibitor, MG132, suggesting that low Pi–induced release of PHO1 repression may result from 26S proteosome–mediated proteolysis. In addition, WRKY42 also showed binding to W-boxes of the PHO1 promoter and repressed PHO1 expression. Our results demonstrate that WRKY6 and WRKY42 are involved in Arabidopsis responses to low Pi stress by regulation of PHO1 expression.Keywords
This publication has 67 references indexed in Scilit:
- Phosphate Starvation Responses and Gibberellic Acid Biosynthesis are Regulated by the MYB62 Transcription Factor in ArabidopsisMolecular Plant, 2009
- Studies on DNA-binding selectivity of WRKY transcription factors lend structural clues into WRKY-domain functionPlant Molecular Biology, 2008
- Networks of WRKY transcription factors in defense signalingCurrent Opinion in Plant Biology, 2007
- Phosphate Homeostasis and Root Development in Arabidopsis Are Synchronized by the Zinc Finger Transcription Factor ZAT6Plant Physiology, 2007
- PHO2, MicroRNA399, and PHR1 Define a Phosphate-Signaling Pathway in PlantsPlant Physiology, 2006
- pho2, a Phosphate Overaccumulator, Is Caused by a Nonsense Mutation in a MicroRNA399 Target GenePlant Physiology, 2006
- Physical and Functional Interactions between Pathogen-Induced Arabidopsis WRKY18, WRKY40, and WRKY60 Transcription FactorsPlant Cell, 2006
- Phosphate AcquisitionPlant and Soil, 2005
- Members of the Arabidopsis WRKY Group III Transcription Factors Are Part of Different Plant Defense Signaling PathwaysMolecular Plant-Microbe Interactions®, 2003
- Electrophoretic transfer of proteins from polyacrylamide gels to nitrocellulose sheets: procedure and some applications.Proceedings of the National Academy of Sciences of the United States of America, 1979