title: Circadian rhythms of hydraulic conductance and growth are enhanced by drought and improve plant performance.
abstract: Circadian rhythms enable plants to anticipate daily environmental variations, resulting in growth oscillations under continuous light. Because plants daily transpire up to 200% of their water content, their water status oscillates from favourable during the night to unfavourable during the day. We show that rhythmic leaf growth under continuous light is observed in plants that experience large alternations of water status during an entrainment period, but is considerably buffered otherwise. Measurements and computer simulations show that this is due to oscillations of plant hydraulic conductance and plasma membrane aquaporin messenger RNA abundance in roots during continuous light. A simulation model suggests that circadian oscillations of root hydraulic conductance contribute to acclimation to water stress by increasing root water uptake, thereby favouring growth and photosynthesis. They have a negative effect in favourable hydraulic conditions. Climate-driven control of root hydraulic conductance therefore improves plant performances in both stressed and non-stressed conditions.
authors.affiliation: INRA, LEPSE, 2 place Viala, F-34060 Montpellier, France.
authors.forename: Cecilio F
authors.initials: CF
authors.lastname: Caldeira
authors.affiliation: Institut des Sciences de la Vie, Université catholique de Louvain, 1 B-1348 Louvain-la-Neuve, Belgium.
authors.forename: Linda
authors.initials: L
authors.lastname: Jeanguenin
authors.affiliation: Institut des Sciences de la Vie, Université catholique de Louvain, 1 B-1348 Louvain-la-Neuve, Belgium.
authors.forename: François
authors.initials: F
authors.lastname: Chaumont
authors.affiliation: INRA, LEPSE, 2 place Viala, F-34060 Montpellier, France.
authors.forename: François
authors.initials: F
authors.lastname: Tardieu
mesh_terms: D000064:Acclimatization; D002940:Circadian Rhythm; D055864:Droughts; D008954:Models, Biological; D018515:Plant Leaves / Q000254:growth & development*; D018517:Plant Roots / Q000502:physiology; D018526:Plant Transpiration; D013312:Stress, Physiological; D014867:Water / Q000502:physiology*; D003313:Zea mays / Q000254:growth & development*
chemical_list: D014867:Water