title: Effects of kinetics of light-induced stomatal responses on photosynthesis and water-use efficiency.
abstract: Both photosynthesis (A) and stomatal conductance (gs ) respond to changing irradiance, yet stomatal responses are an order of magnitude slower than photosynthesis, resulting in noncoordination between A and gs in dynamic light environments. Infrared gas exchange analysis was used to examine the temporal responses and coordination of A and gs to a step increase and decrease in light in a range of different species, and the impact on intrinsic water use efficiency was evaluated. The temporal responses revealed a large range of strategies to save water or maximize photosynthesis in the different species used in this study but also displayed an uncoupling of A and gs in most of the species. The shape of the guard cells influenced the rapidity of response and the overall gs values achieved, with different impacts on A and Wi . The rapidity of gs in dumbbell-shaped guard cells could be attributed to size, whilst in elliptical-shaped guard cells features other than anatomy were more important for kinetics. Our findings suggest significant variation in the rapidity of stomatal responses amongst species, providing a novel target for improving photosynthesis and water use.
authors.affiliation: School of Biological Sciences, University of Essex, Colchester, CO4 3SQ, UK.
authors.forename: Lorna
authors.initials: L
authors.lastname: McAusland
authors.affiliation: School of Biological Sciences, University of Essex, Colchester, CO4 3SQ, UK.
authors.forename: Silvère
authors.initials: S
authors.lastname: Vialet-Chabrand
authors.affiliation: School of Biological Sciences, University of Essex, Colchester, CO4 3SQ, UK.
authors.forename: Philip
authors.initials: P
authors.lastname: Davey
authors.affiliation: School of Biological Sciences, University of Essex, Colchester, CO4 3SQ, UK.
authors.forename: Neil R
authors.initials: NR
authors.lastname: Baker
authors.affiliation: INRA, UMR1137 'Ecologie et Ecophysiologie Forestières', F-54280, Champenoux, France.|UMR1137 'Ecologie et Ecophysiologie Forestières', Faculté des Sciences, Université de Lorraine, F-54500, Vandoeuvre-Les-Nancy, France.
authors.forename: Oliver
authors.initials: O
authors.lastname: Brendel
authors.affiliation: School of Biological Sciences, University of Essex, Colchester, CO4 3SQ, UK.
authors.forename: Tracy
authors.initials: T
authors.lastname: Lawson
mesh_terms: D002245:Carbon Dioxide / Q000378:metabolism; D007700:Kinetics; D008027:Light; D017785:Photons; D010788:Photosynthesis / Q000528:radiation effects*; D054046:Plant Stomata / Q000033:anatomy & histology / Q000502:physiology* / Q000528:radiation effects*; D013045:Species Specificity; D013997:Time Factors; D014867:Water / Q000502:physiology*
chemical_list: D014867:Water; D002245:Carbon Dioxide
keywords: guard cells; intrinsic water use efficiency; kinetics of stomatal responses; photosynthesis; stomatal conductance