Identification of OsbZIP72 as a positive regulator of ABA response and drought tolerance in rice

Planta. 2009 Feb;229(3):605-15. doi: 10.1007/s00425-008-0857-3. Epub 2008 Dec 2.

Abstract

Abscisic Acid (ABA) is an important phytohormone involved in abiotic stress resistance in plants. A group of bZIP transcription factors play important roles in the ABA signaling pathway in Arabidopsis. However, little is known about the function of their orthologs in rice, where they may hold a great potential for developing drought resistant food crops. In this study, our phylogenetic analysis showed that this group of bZIPs was evolutionarily conserved between Arabidopsis and rice, which implies that they may share similar functions. We demonstrated with quantitative RT-PCR that the expressions of most of these OsbZIPs were significantly induced by ABA, ACC, and abiotic stresses. OsbZIP72, a member of this group, was proved to be an ABRE binding factor in rice using the yeast hybrid systems. We showed that it could bind to ABRE and transactivate the downstream reporter genes in yeast, and the transactivity was depending on its N-terminal region. Transgenic rice overexpressing OsbZIP72 showed a hypersensitivity to ABA, elevated levels of expression of ABA response gene such as LEAs, and an enhanced ability of drought tolerance. These results suggest that OsbZIP72 plays a positive role in drought resistance through ABA signaling, and is potential useful for engineering drought tolerant rice.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Abscisic Acid / pharmacology*
  • Arabidopsis / genetics
  • Basic-Leucine Zipper Transcription Factors / genetics
  • Basic-Leucine Zipper Transcription Factors / physiology*
  • Germination
  • Oryza / drug effects
  • Oryza / genetics
  • Oryza / physiology*
  • Phylogeny
  • Plant Proteins / genetics
  • Plant Proteins / physiology*
  • Plants, Genetically Modified / drug effects
  • Plants, Genetically Modified / metabolism
  • Signal Transduction
  • Stress, Physiological*
  • Water / metabolism

Substances

  • Basic-Leucine Zipper Transcription Factors
  • Plant Proteins
  • Water
  • Abscisic Acid