Thermal Analysis of Stomatal Response under Salinity and High Light

Int J Mol Sci. 2021 Apr 28;22(9):4663. doi: 10.3390/ijms22094663.

Abstract

A non-destructive thermal imaging method was used to study the stomatal response of salt-treated Arabidopsis thaliana plants to excessive light. The plants were exposed to different levels of salt concentrations (0, 75, 150, and 220 mM NaCl). Time-dependent thermograms showed the changes in the temperature distribution over the lamina and provided new insights into the acute light-induced temporary response of Arabidopsis under short-term salinity. The initial response of plants, which was associated with stomatal aperture, revealed an exponential growth in temperature kinetics. Using a single-exponential function, we estimated the time constants of thermal courses of plants exposed to acute high light. The saline-induced impairment in stomatal movement caused the reduced stomatal conductance and transpiration rate. Limited transpiration of NaCl-treated plants resulted in an increased rosette temperature and decreased thermal time constants as compared to the controls. The net CO2 assimilation rate decreased for plants exposed to 220 mM NaCl; in the case of 75 mM NaCl treatment, an increase was observed. A significant decline in the maximal quantum yield of photosystem II under excessive light was noticeable for the control and NaCl-treated plants. This study provides evidence that thermal imaging as a highly sensitive technique may be useful for analyzing the stomatal aperture and movement under dynamic environmental conditions.

Keywords: evapotranspiration; excessive light; infrared thermal imaging; light-induced temperature kinetics; photosystem II efficiency; salinity; stomatal conductance.

MeSH terms

  • Arabidopsis / drug effects
  • Arabidopsis / physiology*
  • Arabidopsis / radiation effects*
  • Kinetics
  • Light
  • Osmotic Pressure
  • Photosystem II Protein Complex / drug effects
  • Photosystem II Protein Complex / metabolism
  • Photosystem II Protein Complex / radiation effects
  • Plant Stomata / drug effects
  • Plant Stomata / physiology
  • Plant Stomata / radiation effects
  • Plant Transpiration / drug effects
  • Plant Transpiration / physiology
  • Plant Transpiration / radiation effects
  • Salinity
  • Sodium Chloride / administration & dosage
  • Stress, Physiological
  • Thermography / methods*

Substances

  • Photosystem II Protein Complex
  • Sodium Chloride