title: Role of hydraulic and chemical signals in leaves, stems and roots in the stomatal behaviour of olive trees under water stress and recovery conditions.
abstract: The control of plant transpiration by stomata under water stress and recovery conditions is of paramount importance for plant performance and survival. Although both chemical and hydraulic signals emitted within a plant are considered to play a major role in controlling stomatal dynamics, they have rarely been assessed together. The aims of this study were to evaluate (i) the dynamics of chemical and hydraulic signals at leaf, stem and root level, and (ii) their effect on the regulation of stomatal conductance (gs) during water stress and recovery. Measurements of gs, water potential, abscisic acid (ABA) content and loss of hydraulic functioning at leaf, stem and root level were conducted during a water stress and recovery period imposed on 1-year-old olive plants (Olea europaea L.). Results showed a strong hydraulic segmentation in olive plants, with higher hydraulic functioning losses in roots and leaves than in stems. The dynamics of hydraulic conductance of roots and leaves observed as water stress developed could explain both a protection of the hydraulic functionality of larger organs of the plant (i.e., branches, etc.) and a role in the down-regulation of gs. On the other hand, ABA also increased, showing a similar pattern to gs dynamics, and thus its effect on gs in response to water stress cannot be ruled out. However, neither hydraulic nor non-hydraulic factors were able to explain the delay in the full recovery of gs after soil water availability was restored.
authors.affiliation: Irrigation and Crop Ecophysiology Group, Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS, CSIC), Avenida Reina Mercedes, no. 10, 41012 Sevilla, Spain Department of Agricultural Sciences, University of Bologna, Viale Fanin 46, 40127 Bologna, Italy.
authors.forename: Jose M
authors.initials: JM
authors.lastname: Torres-Ruiz
authors.affiliation: Irrigation and Crop Ecophysiology Group, Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS, CSIC), Avenida Reina Mercedes, no. 10, 41012 Sevilla, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: Diaz-Espejo
authors.affiliation: Irrigation and Crop Ecophysiology Group, Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS, CSIC), Avenida Reina Mercedes, no. 10, 41012 Sevilla, Spain.
authors.forename: Alfonso
authors.initials: A
authors.lastname: Perez-Martin
authors.affiliation: Irrigation and Crop Ecophysiology Group, Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS, CSIC), Avenida Reina Mercedes, no. 10, 41012 Sevilla, Spain virginiahsa@gmail.com.
authors.forename: Virginia
authors.initials: V
authors.lastname: Hernandez-Santana
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism*; D000222:Adaptation, Physiological; D055864:Droughts; D031658:Olea / Q000378:metabolism / Q000502:physiology*; D018515:Plant Leaves; D018517:Plant Roots; D018547:Plant Stems; D054046:Plant Stomata / Q000502:physiology*; D018514:Plant Structures / Q000502:physiology; D018526:Plant Transpiration; D012987:Soil; D013312:Stress, Physiological; D014197:Trees / Q000378:metabolism / Q000502:physiology; D014867:Water / Q000378:metabolism / Q000502:physiology*
chemical_list: D012987:Soil; D014867:Water; D000040:Abscisic Acid
keywords: ABA; hydraulic conductivity; hydraulic segmentation; leaf hydraulic conductance; stomatal conductance