Physiological and biochemical response to photooxidative stress of the fundamental citrus species
2012
Santini , Jérémie (INRA , San Giuliano (France). UR 1103 Génétique et Ecophysiologie de la Qualité des Agrumes) | Giannettini , Jean (CNRS , Corte(France). UMR 6134 SPE, Laboratoire Biochimie et Biologie Moléculaire du Végétal) | Herbette , Stéphane (INRA , Clermont-Ferrand (France). UMR 0547 Physique et Physiologie Intégratives de l'Arbre Fruitier et Forestier) | Pailly , Olivier (INRA , San Giuliano (France). UR 1103 Génétique et Ecophysiologie de la Qualité des Agrumes) | Ollitrault , Patrick (Centre de Coopération Internationale en Recherche Agronomique pour le Développement, Montpellier(France). UPR 75) | Luro , François (INRA , San Giuliano (France). UR 1103 Génétique et Ecophysiologie de la Qualité des Agrumes) | Berti , Liliane (Centre National de la Recherche Scientifique, Corte(France). UMR 6134 - Laboratoire Biochimie et Biologie Moléculaire du Végétal)
Despite the economic importance of citrus, insights on the genetic response to stress are scarce. The aim of the present study was to compare fundamental citrus species for their response to photooxidative stress. The experiment was conducted under orchard conditions on three fundamental citrus species C. medica L., C. reticulata Blanco and C. maxima (Burm.) Merr., and on Fortunella japonica (Thunb.) Swing. We examined their respective net photosynthesis (Pnet), stomatal conductance (Gs) and chlorophyll fluorescence (Fv/Fm) on sun-acclimated leaves and shade-acclimated leaves returned under natural sunlight irradiance. To compare the respective response mechanism, we analyzed changes in oxidative status (hydrogen peroxide (H2O2) and malondialdehyde (MDA)), reactive oxygen species (ROS)-scavenging enzymes (superoxide dismutase (SOD), catalase, ascorbate peroxidase), recycling enzymes (monodehydroascorbate reductase, dehydroascorbate reductase and glutathione reductase) and antioxidant metabolites (ascorbate and glutathione). Kumquat and pummelo exposed lower down-regulation and full recovery of photosynthetic parameters, lower accumulation of oxidized compounds associated with greater production of reduced glutathione (Gsh) and enhanced activity of the three ROS scavenging enzymes, especially SOD. Citron and mandarin showed a marked decrease and incomplete recovery in photosynthetic performance, mainly in Pnet and Fv/Fm, larger accumulation of oxidative parameters, slighter induction of antioxidant enzymes and down-regulation of reduced ascorbate (Asa) and Gsh synthesis. These results suggest that kumquat and pummelo have a greater tolerance to photooxidative stress than citron and mandarin.
Show more [+] Less [-]AGROVOC Keywords
Bibliographic information
This bibliographic record has been provided by Institut national de la recherche agronomique