Effect of Leaf Water Potential on Internal Humidity and CO₂ Dissolution: Reverse Transpiration and Improved Water Use Efficiency under Negative Pressure.

ABSTRACT: The pull of water from the soil to the leaves causes water in the transpiration stream to be under negative pressure decreasing the water potential below zero. The osmotic concentration also contributes to the decrease in leaf water potential but with much lesser extent. Thus, the surface tension force is approximately balanced by a force induced by negative water potential resulting in concavely curved water-air interfaces in leaves. The lowered water potential causes a reduction in the equilibrium water vapor pressure in internal (sub-stomatal/intercellular) cavities in relation to that over water with the potential of zero, i.e., over the flat surface. The curved surface causes a reduction also in the equilibrium vapor pressure of dissolved CO₂, thus enhancing its physical so

SUBMITTER: Vesala T 

PROVIDER: S-EPMC5292819 | biostudies-literature | 2017

REPOSITORIES: biostudies-literature