Diego A. Márquez

@dmarquez.bsky.social

689 Followers 333 Following

I am a Plant Physiologist interested in water and CO2 movement within the leaf | Research Fellow Busch Lab | Born at 345 ppm atmospheric CO2

Sunny day in Birmingham… lunch on the grass today, and a storm tomorrow for sure 🤣
Detailed representation of H2O gas exchange (left) and CO2 gas exchange (right) at the adaxial (upper) and abaxial (lower) leaf surfaces in an amphistomatous leaf. This panel illustrates the separate gas exchange processes for each leaf surface, which can be measured individually if the upper and lower cuvettes are analysed separately—though this setup is not common in commercial gas exchange systems. Stomatal, cuticle, and boundary layer resistances are depicted for both surfaces, along with the mole fractions of water vapour and CO2.
Diagram of the mechanism of nonstomatal control of transpiration as VPD increases, generating unsaturation in the substomatal cavity. The parameters in the figure are atmospheric water vapour concentration (wa), water vapour concentration on the leaf surface (ws), substomatal cavity water vapour concentration (wi), water vapour concentration at saturation (wsat), resistance to water diffusion through the plasma membrane (rp), cell wall water potential (Ψw), and cytosolic water potential (Ψc). Black dots represent cell wall fibres. The current theory suggests that aquaporins acting as transmembrane conduits close when VPD rises, increasing the resistance to water movement through the membrane of mesophyll cells (rp) and triggering unsaturation in the substomatal cavity.