Find Paper, Faster
Example:10.1021/acsami.1c06204 or Chem. Rev., 2007, 107, 2411-2502
Guard cell endomembrane Ca2+-ATPases underpin a ‘carbon memory’ of photosynthetic assimilation that impacts on water-use efficiency
Nature Plants  (IF15.793),  Pub Date : 2021-07-29, DOI: 10.1038/s41477-021-00966-2
Mareike Jezek, Fernanda A. L. Silva-Alvim, Adrian Hills, Naomi Donald, Maryam Rahmati Ishka, Jessica Shadbolt, Bingqing He, Tracy Lawson, Jeffrey F. Harper, Yizhou Wang, Virgilio L. Lew, Michael R. Blatt

Stomata of most plants close to preserve water when the demand for CO2 by photosynthesis is reduced. Stomatal responses are slow compared with photosynthesis, and this kinetic difference erodes assimilation and water-use efficiency under fluctuating light. Despite a deep knowledge of guard cells that regulate the stoma, efforts to enhance stomatal kinetics are limited by our understanding of its control by foliar CO2. Guided by mechanistic modelling that incorporates foliar CO2 diffusion and mesophyll photosynthesis, here we uncover a central role for endomembrane Ca2+ stores in guard cell responsiveness to fluctuating light and CO2. Modelling predicted and experiments demonstrated a delay in Ca2+ cycling that was enhanced by endomembrane Ca2+-ATPase mutants, altering stomatal conductance and reducing assimilation and water-use efficiency. Our findings illustrate the power of modelling to bridge the gap from the guard cell to whole-plant photosynthesis, and they demonstrate an unforeseen latency, or ‘carbon memory’, of guard cells that affects stomatal dynamics, photosynthesis and water-use efficiency.