Expression of Stipa purpurea SpCIPK26 in Arabidopsis thaliana Enhances Salt and Drought Tolerance and Regulates Abscisic Acid Signaling

Int J Mol Sci. 2016 Jun 22;17(6):966. doi: 10.3390/ijms17060966.

Abstract

Stipa purpurea (S. purpurea) is the dominant plant species in the alpine steppe of the Qinghai-Tibet Plateau, China. It is highly resistant to cold and drought conditions. However, the underlying mechanisms regulating the stress tolerance are unknown. In this study, a CIPK gene from S. purpurea (SpCIPK26) was isolated. The SpCIPK26 coding region consisted of 1392 bp that encoded 464 amino acids. The protein has a highly conserved catalytic structure and regulatory domain. The expression of SpCIPK26 was induced by drought and salt stress. SpCIPK26 overexpression in Arabidopsis thaliana (A. thaliana) plants provided increased tolerance to drought and salt stress in an abscisic acid (ABA)-dependent manner. Compared with wild-type A. thaliana plants, SpCIPK26-overexpressing plants had higher survival rates, water potentials, and photosynthetic efficiency (Fv/Fm), as well as lower levels of reactive oxygen species (ROS) following exposure to drought and salt stress. Gene expression analyses indicated stress-inducible genes (RD29A, RD29B, and ABF2) and a ROS-scavenger gene (CAT1) were upregulated in SpCIPK26-overexpressing plants after stress treatments. All of these marker genes are associated with ABA-responsive cis-acting elements. Additionally, the similarities in the gene expression patterns following ABA, mannitol, and NaCl treatments suggest SpCIPK26 has an important role during plant responses to drought and salt stress and in regulating ABA signaling.

Keywords: ABA; CIPK; ROS; Stipa purpurea; drought; salt.

MeSH terms

  • Arabidopsis / genetics*
  • Arabidopsis / metabolism
  • Arabidopsis Proteins / chemistry
  • Arabidopsis Proteins / genetics*
  • Arabidopsis Proteins / metabolism
  • Catalase / genetics
  • Catalase / metabolism
  • Cold Shock Proteins and Peptides / genetics
  • Cold Shock Proteins and Peptides / metabolism
  • Conserved Sequence
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism
  • Droughts
  • Gene Expression Regulation, Plant
  • Poaceae / genetics
  • Protein Domains
  • Protein Kinases / chemistry
  • Protein Kinases / genetics*
  • Protein Kinases / metabolism
  • Reactive Oxygen Species / metabolism
  • Salt Tolerance / genetics*
  • Stress, Physiological*
  • Transcription Factors / genetics
  • Transcription Factors / metabolism
  • Transgenes*
  • Up-Regulation

Substances

  • ABF2 protein, Arabidopsis
  • Arabidopsis Proteins
  • Cold Shock Proteins and Peptides
  • DNA-Binding Proteins
  • RD29B protein, Arabidopsis
  • RD29a protein, Arabidopsis
  • Reactive Oxygen Species
  • Transcription Factors
  • Catalase
  • CIPK26 protein, Arabidopsis
  • Protein Kinases