Université Bordeaux Segalen Année 2011 Thèse n°1864 THÈSE pour le DOCTORAT DE L’UNIVERSITÉ BORDEAUX 2 Mention: Sciences, Technologie, Santé Option: Biologie végétale Présentée et soutenue publiquement Le 19 Décembre 2011 Par Anthony PECCOUX Né le 26 Mars 1980 à Annecy (Haute-Savoie, France) Molecular and physiological characterization of grapevine rootstock adaptation to drought Membres du Jury Prof. Dr. C. LOVISOLO .................. .University of Torino............................ Président du jury Prof. Dr. G.R. CRAMER ................. .University of Nevada........................... Rapporteur Dr. T. SIMONNEAU ....................... .INRA Montpellier ............................... Rapporteur Dr. M.-B. BOGEAT-TRIBOULOT. .INRA Nancy........................................ Examinateur Prof. Dr. S. DELROT....................... University of Bordeaux. ...................... Examinateur Dr. N. OLLAT.................................. INRA Bordeaux................................... Co-directrice de thèse Prof. Dr. H.R. SCHULTZ ................ .Geisenheim Research Center............... Co-directeur de thèse Université Bordeaux Segalen Année 2011 Thèse n°1864 THÈSE pour le DOCTORAT DE L’UNIVERSITÉ BORDEAUX 2 Mention: Sciences, Technologie, Santé Option: Biologie végétale Présentée et soutenue publiquement Le 19 Décembre 2011 Par Anthony PECCOUX Né le 26 Mars 1980 à Annecy (Haute-Savoie, France) Molecular and physiological characterization of grapevine rootstock adaptation to drought Membres du Jury Prof. Dr. C. LOVISOLO .................. .University of Torino............................ Président du jury Prof. Dr. G.R. CRAMER ................. .University of Nevada........................... Rapporteur Dr. T. SIMONNEAU ....................... .INRA Montpellier ............................... Rapporteur Dr. M.-B. BOGEAT-TRIBOULOT. .INRA Nancy........................................ Examinateur Prof. Dr. S. DELROT....................... University of Bordeaux. ...................... Examinateur Dr. N. OLLAT.................................. INRA Bordeaux................................... Co-directrice de thèse Prof. Dr. H.R. SCHULTZ ................ .Geisenheim Research Center............... Co-directeur de thèse “Les espèces qui survivent ne sont pas les espèces les plus fortes, ni les plus intelligentes, mais celles qui s’adaptent le mieux aux changements” Charles DARWIN (1809-1882) Pour mes parents et ma famille Acknowledgements We acknowledge the generous financial support of the "Studienstrukturprogramm, Doktorandenkolleg Hochschule RheinMain und Forschungsanstalt Geisenheim" of the State of Hesse, Germany. This project is also founded by grants from the Aquitaine region and CIVB, “Conseil Interprofessionnel des Vins de Bordeaux”, both are deeply acknowledged for their kind support. I would also like to thank all the members of my PhD committee for reviewing this work and their critical insights and valuable suggestions. This project was a collaboration between two laboratories in France and Germany. I am very grateful to my two supervisors for their guidance, support and advice during my PhD studies. I wish to express my deep gratitude to all the colleagues in these labs for their technical assistance, their suggestions, and critical reading and improvement of the manuscript. The many scientific interactions, both sharing and combining knowledge with colleagues, have contributed to the different approaches in this thesis, providing me a valuable and broad scientific background. These interactions were crucial to the advancement of my research and my progress as a scientist. I therefore wish to give special thanks to these collaborators. Hopefully we will have many more meaningful exchanges and collaborations in the future. During this thesis, I met many amazing friends and I would like to thank all of them. We shared many scientific exchanges, and their friendship has made the daily life of my PhD more enjoyable and fulfilling. Last but not least, I wish to show my tremendous gratitude towards my parents and my family for their daily support and for making me who I am. Abstract Climate change raises concerns about temporal and spatial water availability in many grape growing countries. The rapidly increasing world population and the scarcity of suitable land for agricultural food production, together with a changing climate, will increase competition with grape-producing areas for the use of land and resources. Consequently, other practices that can potentially improve water management of vineyards and water acquisition by grapevines need to be considered. Aside from canopy systems and their management, the choice of plant material is a key issue. Therefore, in the present work, the role of different rootstocks, regarding their tolerance to drought, was investigated for their potential effects on i) water uptake, ii ) water transport and iii ) shoot water use, using a combination of ecophysiological, modelling and transcriptomic approaches. Experiments were conducted under controlled conditions to decipher short and long term responses to drought of different rootstocks grafted with the same scion. An ecophysiological model was used to investigate the roles of rootstock genotypes in the control of stomatal aperture. Long-term steady state water-deficit conditions were used to examine the responses of i) whole plant growth, root anatomy and hydraulic properties and ii ) transcriptome remodelling in the roots. Our model showed that rootstock affect stomatal aperture of the grafted scion via coordinated processes between root traits, hydraulic signals and chemical signals. Stomatal conductance, transpiration rate and leaf-specific hydraulic conductance were higher and better maintained under well-watered and moderate water-deficit conditions in the drought-tolerant genotype (110 Richter) compared to the drought-sensitive one ( Vitis riparia cv. Gloire de Montpellier). We identified several genotype-specific parameters which play important roles, like root-related parameters, in the control of stomatal regulation. Additionally, root system architecture and root hydraulic properties are important constitutive traits identified between rootstocks. Long-term water-deficit induced genotype adaptive responses in the roots were evaluated. The drought-tolerant genotype exhibited a substantial shift in root tips xylem conduit diameter under moderate water-deficit while the drought-sensitive genotype did not respond. Transcriptomic analysis identified genotype-specific transcripts that are regulated by water- deficit levels. The comparison between stress levels and genotypes identified 24 significant genes in “treatment×genotype” interactions, most of them were involved in lipid metabolism and cell wall processes. These genes displayed genotype-specific water-deficit response curves. Protection against drought-induced oxidative damage was found to be an important mechanisms induced by the drought-tolerant rootstock, while the drought-sensitive one responds to water-deficit by modification of cell wall properties. Keywords : grapevine, rootstock, Vitis spp. , roots, water stress, drought, transcriptomic, modelling, gas exchange, hydraulic signalling, chemical signalling Address of the laboratory in France UMR 1287 Ecophysiologie et Génomique Fonctionnelle de la Vigne (EGFV) Institut National de la Recherche Agronomique (INRA), UB2, UB1, ENITA Institut des Sciences de la Vigne et du Vin (ISVV) 210, Chemin de Leysotte F-33882 Villenave d’Ornon (France) Address of the laboratory in Germany Forschungsanstalt Geisenheim Fachgebiet Weinbau Von Lade Strasse 1 D-65366 Geisenheim (Germany) Table of contents List of abbreviations and frequently used symbols .............................................................................I List of figures ........................................................................................................................................ II List of tables....................................................................................................................................... VII Chapter I. General introduction ......................................................................................................- 8 - I.1 Context of the present studies..............................................................................................................- 13 - I.1.1 Global warming: new challenges for facing the future ...................................................................- 13 - I.1.1.1 General considerations ..............................................................................................................................- 13 - I.1.1.2 What about grapevine?..............................................................................................................................- 14 - I.2 Objectives and outlines of the thesis....................................................................................................- 15 - I.2.1 Objectives of the thesis ...................................................................................................................- 16 - I.2.2 Outline of the thesis.........................................................................................................................- 17 - I.3 Paper publishing and conference communication .............................................................................- 18 - I.3.1 Posters .............................................................................................................................................-