title: Inflorescences vs leaves: a distinct modulation of carbon metabolism process during Botrytis infection.
abstract: Plant growth and survival depends critically on photo assimilates. Pathogen infection leads to changes in carbohydrate metabolism of plants. In this study, we monitored changes in the carbohydrate metabolism in the grapevine inflorescence and leaves using Botrytis cinerea and Botrytis pseudo cinerea. Fluctuations in gas exchange were correlated with variations in chlorophyll a fluorescence. During infection, the inflorescences showed an increase in net photosynthesis (Pn) with a stomatal limitation. In leaves, photosynthesis decreased, with a non-stomatal limitation. A decrease in the effective photosystem II (PSII) quantum yield (ΦPSII) was accompanied by an increase in photochemical quenching (qP) and non-photochemical quenching (qN). The enhancement of qP and ΦPSII could explain the observed increase in Pn. In leaves, the significant decline in ΦPSII and qP, and increase in qN suggest that energy was mostly oriented toward heat dissipation instead of CO2 fixation. The accumulation of glucose and sucrose in inflorescences and glucose and fructose in the leaves during infection indicate that the plant's carbon metabolism is differently regulated in these two organs. While a strong accumulation of starch was observed at 24 and 48 hours post-inoculation (hpi) with both species of Botrytis in the inflorescences, a significant decrease with B. cinerea at 24 hpi and a significant increase with B. pseudo cinerea at 48 hpi were observed in the leaves. On the basis of these results, it can be said that during pathogen attack, the metabolism of grapevine inflorescence and leaf is modified suggesting distinct mechanisms modifying gas exchange, PSII activity and sugar contents in these two organs.
authors.affiliation: Laboratoire de Stress, Défenses et Reproduction des Plantes, Unité de Recherche Vigne et Vin de Champagne URVVC EA 4707, Université de Reims Champagne-Ardenne, UFR Sciences Exactes et Naturelles, Reims, F-51687, France.
authors.forename: Parul
authors.initials: P
authors.lastname: Vatsa-Portugal
authors.forename: Anne-Sophie
authors.initials: AS
authors.lastname: Walker
authors.forename: Lucile
authors.initials: L
authors.lastname: Jacquens
authors.forename: Christophe
authors.initials: C
authors.lastname: Clément
authors.forename: Essaid Ait
authors.initials: EA
authors.lastname: Barka
authors.forename: Nathalie
authors.initials: N
authors.lastname: Vaillant-Gaveau
mesh_terms: D020171:Botrytis / Q000502:physiology*; D050260:Carbohydrate Metabolism; D002245:Carbon Dioxide / Q000378:metabolism; D025141:Drug Resistance, Fungal; D035263:Flowering Tops / Q000378:metabolism; D005838:Genotype; D054884:Host-Pathogen Interactions; D045332:Photosystem II Protein Complex / Q000378:metabolism; D018515:Plant Leaves / Q000378:metabolism; D027843:Vitis / Q000382:microbiology*
chemical_list: D045332:Photosystem II Protein Complex; D002245:Carbon Dioxide