Smaller, faster stomata: scaling of stomatal size, rate of response, and stomatal conductance

J Exp Bot. 2013 Jan;64(2):495-505. doi: 10.1093/jxb/ers347. Epub 2012 Dec 21.

Abstract

Maximum and minimum stomatal conductance, as well as stomatal size and rate of response, are known to vary widely across plant species, but the functional relationship between these static and dynamic stomatal properties is unknown. The objective of this study was to test three hypotheses: (i) operating stomatal conductance under standard conditions (g (op)) correlates with minimum stomatal conductance prior to morning light [g (min(dawn))]; (ii) stomatal size (S) is negatively correlated with g (op) and the maximum rate of stomatal opening in response to light, (dg/dt)(max); and (iii) g (op) correlates negatively with instantaneous water-use efficiency (WUE) despite positive correlations with maximum rate of carboxylation (Vc (max)) and light-saturated rate of electron transport (J (max)). Using five closely related species of the genus Banksia, the above variables were measured, and it was found that all three hypotheses were supported by the results. Overall, this indicates that leaves built for higher rates of gas exchange have smaller stomata and faster dynamic characteristics. With the aid of a stomatal control model, it is demonstrated that higher g (op) can potentially expose plants to larger tissue water potential gradients, and that faster stomatal response times can help offset this risk.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carbon Dioxide / metabolism
  • Electron Transport
  • Electrophysiological Phenomena
  • Kinetics
  • Light
  • Plant Stomata / chemistry*
  • Plant Stomata / metabolism
  • Plant Stomata / radiation effects
  • Proteaceae / chemistry*
  • Proteaceae / metabolism
  • Proteaceae / radiation effects
  • Water / metabolism

Substances

  • Water
  • Carbon Dioxide