The maize OST1 kinase homolog phosphorylates and regulates the maize SNAC1-type transcription factor

PLoS One. 2013;8(2):e58105. doi: 10.1371/journal.pone.0058105. Epub 2013 Feb 28.

Abstract

The Arabidopsis kinase OPEN STOMATA 1 (OST1) plays a key role in regulating drought stress signalling, particularly stomatal closure. We have identified and investigated the functions of the OST1 ortholog in Z. mays (ZmOST1). Ectopic expression of ZmOST1 in the Arabidopsis ost1 mutant restores the stomatal closure phenotype in response to drought. Furthermore, we have identified the transcription factor, ZmSNAC1, which is directly phosphorylated by ZmOST1 with implications on its localization and protein stability. Interestingly, ZmSNAC1 binds to the ABA-box of ZmOST1, which is conserved in SnRK2s activated by ABA and is part of the contact site for the negative-regulating clade A PP2C phosphatases. Taken together, our results indicate that ZmSNAC1 is a substrate of ZmOST1 and delineate a novel osmotic stress transcriptional pathway in maize.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Abscisic Acid / pharmacology
  • Amino Acid Sequence
  • Arabidopsis Proteins / chemistry*
  • Arabidopsis Proteins / metabolism*
  • Droughts
  • Molecular Sequence Data
  • Oryza / metabolism
  • Phosphorylation / drug effects
  • Plant Stomata / anatomy & histology
  • Plant Stomata / genetics
  • Protein Kinases / chemistry*
  • Protein Kinases / metabolism*
  • Protein Stability / drug effects
  • Protein Transport / drug effects
  • Sequence Homology, Amino Acid*
  • Stress, Physiological / genetics
  • Transcription Factors / metabolism*
  • Zea mays / anatomy & histology
  • Zea mays / drug effects
  • Zea mays / enzymology*
  • Zea mays / metabolism

Substances

  • Arabidopsis Proteins
  • Transcription Factors
  • Abscisic Acid
  • Protein Kinases
  • OST1 protein, Arabidopsis

Grants and funding

BV was financed by Fundação para a Ciência e Tecnologia PhD grant SFRH/BD/62070/2009 and European Union Marie-Curie Early Stage Training Fellowships MEST-CT-2005-020232-2 ADONIS. This work was supported by Consolider-Ingenio 2010CSD2007-00036 from MCYT (Spain) and grants BIO2009-13044 from MCYT (Spain) and CIRIT2009SGR626 from Comissionat per Universitats i Recerca de la Generalitat de Catalunya to MP. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.