title: Turgidity-dependent petiole flexibility enables efficient water use by a tree subjected to water stress.
abstract: Water stress is a major cause of tree mortality. In response to drought, leaves wilt due to an increase in petiole flexibility. We present an analytical model coupling petiole mechanics, thermal balance, and xylem hydraulics to investigate the role of petiole flexibility in protecting a tree from water stress. Our model suggests that turgidity-dependent petiole flexibility can significantly attenuate the minimal xylem pressure and thus reduce the risk of cavitation. Moreover, we show that petiole flexibility increases water use efficiency by trees under water stress.
authors.affiliation: Hydrodynamics Laboratory (LadHyX), École Polytechnique, 91128 Palaiseau, France. Electronic address: davidgr@alum.mit.edu.
authors.forename: David
authors.initials: D
authors.lastname: Gonzalez-Rodriguez
authors.affiliation: MAS Laboratory, École Centrale Paris, 92160 Châtenay-Malabry, France.
authors.forename: Paul-Henry
authors.initials: PH
authors.lastname: Cournède
authors.affiliation: Hydrodynamics Laboratory (LadHyX), École Polytechnique, 91128 Palaiseau, France.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: de Langre
mesh_terms: D001696:Biomechanical Phenomena; D002245:Carbon Dioxide / Q000378:metabolism; D003681:Dehydration; D008954:Models, Biological; D010788:Photosynthesis / Q000502:physiology; D018515:Plant Leaves / Q000502:physiology*; D054046:Plant Stomata / Q000502:physiology; D012987:Soil; D014197:Trees / Q000502:physiology*; D014867:Water / Q000502:physiology*
chemical_list: D012987:Soil; D014867:Water; D002245:Carbon Dioxide
keywords: Biomechanics; Cavitation; Drought; Leaf; Photosynthesis; Turgor pressure; Water stress; Wilting