The role of calcium in ABA-induced gene expression and stomatal movements

Plant J. 2001 May;26(3):351-62. doi: 10.1046/j.1365-313x.2001.01032.x.


There is much interest in the transduction pathways by which abscisic acid (ABA) regulates stomatal movements (ABA-turgor signalling) and by which this phytohormone regulates the pattern of gene expression in plant cells (ABA-nuclear signalling). A number of second messengers have been identified in both the ABA-turgor and ABA-nuclear signalling pathways. A major challenge is to understand the architecture of ABA-signalling pathways and to determine how the ABA signal is coupled to the appropriate response. We have investigated whether separate Ca2+-dependent and -independent ABA-signalling pathways are present in guard cells. Our data suggest that increases in [Ca2+]i are a common component of the guard cell ABA-turgor and ABA-nuclear signalling pathways. The effects of Ca2+ antagonists on ABA-induced stomatal closure and the ABA-responsive CDeT6-19 gene promoter suggest that Ca2+ is involved in both ABA-turgor signalling and ABA-nuclear signalling in guard cells. However, the sensitivity of these pathways to alterations in the external calcium concentration differ, suggesting that the ABA-nuclear and ABA-turgor signalling pathways are not completely convergent. Our data suggest that whilst Ca2+-independent signalling elements are present in the guard cell, they do not form a completely separate Ca2+-independent ABA-signalling pathway.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Abscisic Acid / physiology*
  • Arabidopsis / cytology
  • Arabidopsis / physiology
  • Calcium / physiology*
  • Gene Expression Regulation, Plant*
  • Magnoliopsida / cytology
  • Magnoliopsida / physiology
  • Plant Leaves / cytology
  • Plant Leaves / physiology
  • Plant Proteins / genetics
  • Signal Transduction


  • CDeT6-19 protein, Craterostigma plantagineum
  • Plant Proteins
  • Abscisic Acid
  • Calcium