The NF-YA transcription factor OsNF-YA7 confers drought stress tolerance of rice in an abscisic acid independent manner

Plant Sci. 2015 Dec:241:199-210. doi: 10.1016/j.plantsci.2015.10.006. Epub 2015 Oct 22.

Abstract

The mechanisms of plant response and adaptation to drought stress require the regulation of transcriptional networks via the induction of drought-responsive transcription factors. Nuclear Factor Y (NF-Y) transcription factors have aroused interest in roles of plant drought stress responses. However, the molecular mechanism of the NF-Y-induced drought tolerance is not well understood. Here, we functionally analyzed two rice NF-YA genes, OsNF-YA7 and OsNF-YA4. Expression of OsNF-YA7 was induced by drought stress and its overexpression in transgenic rice plants improved their drought tolerance. In contrast, OsNF-YA4 expression was not increased by drought stress and its overexpression in transgenic rice plants did not affect their sensitivity to drought stress. OsNF-YA4 expression was highly induced by the stress-related hormone abscisic acid (ABA), while OsNF-YA7 was not, indicating that OsNF-YA7 mediates drought tolerance in an ABA-independent manner. Analysis of the OsNF-YA7 promoter revealed three ABA-independent DRE/CTR elements and RNA-seq analysis identified 48 genes downstream of OsNFYA7 action putatively involved in the OsNF-YA7-mediated drought tolerance pathway. Taken together, our results suggest an important role for OsNF-YA7 in rice drought stress tolerance.

Keywords: Abscisic acid; Drought tolerance; Nuclear factor (NF)-YA; Rice; Transcription factor.

MeSH terms

  • Abscisic Acid / metabolism*
  • CCAAT-Binding Factor
  • Droughts*
  • Gene Expression Regulation, Plant*
  • Oryza / genetics
  • Oryza / physiology*
  • Plant Proteins / genetics*
  • Plant Proteins / metabolism
  • Plants, Genetically Modified / genetics
  • Plants, Genetically Modified / physiology
  • Stress, Physiological
  • Transcription Factors / genetics*
  • Transcription Factors / metabolism

Substances

  • CCAAT-Binding Factor
  • Plant Proteins
  • Transcription Factors
  • nuclear factor Y
  • Abscisic Acid