Stomata conductance as a goalkeeper for increased photosynthetic efficiency

100-120 words. References should not be included. Abbreviations should be avoided as far as possible. Low stomatal conductance (gs) poses a major constraint for improving photosynthetic efficiency for greater yield. Options at the molecular, leaf, canopy, and even the whole plant scales can be developed to enhance gs for greater light and water use efficiencies. Among these, many genes regulating stomatal development and stomatal movement have been discovered and manipulated to increase light and water use efficiencies under well-watered, drought, or facility agriculture conditions with the manual-controlled growth environmental. Optimization of canopy conductance to increase whole plant photosynthesis with full consideration of the heterogeneities in gs, microclimates and leaf ontology inside the canopy represents a largely uncharted area to improve crop efficiency.