Unique responsiveness of angiosperm stomata to elevated CO2 explained by calcium signalling

PLoS One. 2013 Nov 20;8(11):e82057. doi: 10.1371/journal.pone.0082057. eCollection 2013.

Abstract

Angiosperm and conifer tree species respond differently when exposed to elevated CO2, with angiosperms found to dynamically reduce water loss while conifers appear insensitive. Such distinct responses are likely to affect competition between these tree groups as atmospheric CO2 concentration rises. Seeking the mechanism behind this globally important phenomenon we targeted the Ca(2+)-dependent signalling pathway, a mediator of stomatal closure in response to elevated CO2, as a possible explanation for the differentiation of stomatal behaviours. Sampling across the diversity of vascular plants including lycophytes, ferns, gymnosperms and angiosperms we show that only angiosperms possess the stomatal behaviour and prerequisite genetic coding, linked to Ca(2+)-dependent stomatal signalling. We conclude that the evolution of Ca(2+)-dependent stomatal signalling gives angiosperms adaptive benefits in terms of highly efficient water use, but that stomatal sensitivity to high CO2 may penalise angiosperm productivity relative to other plant groups in the current era of soaring atmospheric CO2.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Abscisic Acid / metabolism
  • Calcium Signaling*
  • Carbon Dioxide / metabolism*
  • Dark Adaptation
  • Genes, Plant
  • Light
  • Magnoliopsida / genetics
  • Magnoliopsida / metabolism
  • Magnoliopsida / physiology*
  • Plant Stomata / physiology*

Substances

  • Carbon Dioxide
  • Abscisic Acid

Grant support

This study was funded by Australian Research Council (http://www.arc.gov.au/) grants DP0878177 and FT100100237 (to TB). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.