title: Variations in physiological and biochemical traits of oak seedlings grown under drought and ozone stress.
abstract: Despite the huge biodiversity characterizing the Mediterranean environment, environmental constraints, such as high sunlight and high temperatures alongside with dry periods, make plant survival hard. In addition, high irradiance leads to increasing ozone (O3 ) concentrations in ambient air. In this era of global warming, it is necessary to understand the mechanisms that allow native species to tolerate these environmental constraints and how such mechanisms interact. Three Mediterranean oak species (Quercus ilex, Quercus pubescens and Quercus cerris) with different features (drought tolerant, evergreen or deciduous species) were selected to assess their biometrical, physiological and biochemical responses under drought and/or O3 stress (80-100 nl l(-1) of O3 for 5 h day(-1) for 77 consecutive days). Leaf visible injury appeared only under drought stress (alone or combined with O3 ) in all three species. Drought × O3 induced strong reductions in leaf dry weight in Q. pubescens and Q. cerris (-70 and -75%, respectively). Alterations in physiological (i.e. decrease in maximum carboxylation rate) and biochemical parameters (i.e. increase in proline content and build-up of malondialdehyde by-products) occurred in all the three species, although drought represented the major determinant. Quercus ilex and Q. pubescens, which co-occur in dry environments, were more tolerant to drought and drought × O3 . Quercus ilex was the species in which oxidative stress occurred only when drought was applied with O3 . High plasticity at a biochemical level (i.e. proline content) and evergreen habitus are likely on the basis of the higher tolerance of Q. ilex.
authors.affiliation: Department of Agriculture, Food and Environment, University of Pisa, Via del Borghetto, 80, 56124, Pisa, Italy.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Cotrozzi
authors.affiliation: Department of Agriculture, Food and Environment, University of Pisa, Via del Borghetto, 80, 56124, Pisa, Italy.
authors.forename: Damiano
authors.initials: D
authors.lastname: Remorini
authors.affiliation: Department of Agriculture, Food and Environment, University of Pisa, Via del Borghetto, 80, 56124, Pisa, Italy.
authors.forename: Elisa
authors.initials: E
authors.lastname: Pellegrini
authors.affiliation: Department of Agriculture, Food and Environment, University of Pisa, Via del Borghetto, 80, 56124, Pisa, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Landi
authors.affiliation: Department of Agriculture, Food and Environment, University of Pisa, Via del Borghetto, 80, 56124, Pisa, Italy.
authors.forename: Rossano
authors.initials: R
authors.lastname: Massai
authors.affiliation: Department of Agriculture, Food and Environment, University of Pisa, Via del Borghetto, 80, 56124, Pisa, Italy.
authors.forename: Cristina
authors.initials: C
authors.lastname: Nali
authors.affiliation: Department of Agriculture, Food and Environment, University of Pisa, Via del Borghetto, 80, 56124, Pisa, Italy.
authors.forename: Lucia
authors.initials: L
authors.lastname: Guidi
authors.affiliation: Department of Agriculture, Food and Environment, University of Pisa, Via del Borghetto, 80, 56124, Pisa, Italy.
authors.forename: Giacomo
authors.initials: G
authors.lastname: Lorenzini
mesh_terms: D000064:Acclimatization; D055864:Droughts; D004777:Environment; D057232:Global Warming; D006358:Hot Temperature; D008315:Malondialdehyde / Q000378:metabolism; D018384:Oxidative Stress; D010126:Ozone / Q000009:adverse effects*; D018515:Plant Leaves / Q000502:physiology; D029963:Quercus / Q000502:physiology*; D013045:Species Specificity
chemical_list: D008315:Malondialdehyde; D010126:Ozone