title: Effect of the herbicide flumioxazin on photosynthetic performance of grapevine (Vitis vinifera L.).
abstract: Among the herbicides used in vineyards, the pre-emergence soil-applied flumioxazin (fmx) is a recently used molecule that inhibits chlorophyll biosynthesis in weed species. The aim of this work is to further characterize the effects of fmx on the non-target grapevine (Vitis vinifera L. cv. Chardonnay) using cutting as a model. Several photosynthesis parameters were estimated during 25 days after treatment with various fmx concentrations (from 0.5mM to 50mM). Measuring chlorophyll fluorescence it appeared that fmx or a by-product penetrated the plant throughout roots and spread throughout vessels. Besides the initial target, protox, fmx affected other functions related to photosynthesis. Fmx induced a simultaneous drop of both P(n), g(s) and T. Fmx caused stomatal closure, which partially explains the decrease of the net photosynthesis. The decline in F(v)/F(m) indicates that the photochemistry of PSII and its ability to reduce the primary acceptor Q(A) are also affected by fmx in grapevine. Fmx leads to a decrease in the coefficients of both photochemical and non-photochemical quenching. Simultaneous stomatal closure and decrease in the quantum yield of CO(2) assimilation indicate a change in energy metabolism following fmx stress. After ten days of fmx treatment, analyses of the response of net carbon assimilation in leaves to different intercellular CO(2) concentrations have shown a decrease of the maximum carboxylation velocity of RuBP. Stomatal closure, PSII photochemistry, change in energy metabolism and RuBP activity were affected by fmx treatment.
authors.affiliation: Laboratoire de Stress, Défenses et Reproduction des Plantes, URVVC EA 2069, Université de Reims Champagne-Ardenne, UFR Sciences Exactes et Naturelles, Bâtiment 18, Moulin de la Housse - BP 1039, F-51687 Reims Cedex 2, France.
authors.forename: Aurélie
authors.initials: A
authors.lastname: Bigot
authors.forename: Florence
authors.initials: F
authors.lastname: Fontaine
authors.forename: Christophe
authors.initials: C
authors.lastname: Clément
authors.forename: Nathalie
authors.initials: N
authors.lastname: Vaillant-Gaveau
mesh_terms: D048588:Benzoxazines / Q000009:adverse effects*; D002734:Chlorophyll / Q000378:metabolism; D000077194:Chlorophyll A; D006540:Herbicides / Q000009:adverse effects*; D010788:Photosynthesis / Q000187:drug effects*; D010797:Phthalimides / Q000009:adverse effects*; D013050:Spectrometry, Fluorescence; D027843:Vitis / Q000187:drug effects* / Q000502:physiology
chemical_list: D048588:Benzoxazines; D006540:Herbicides; D010797:Phthalimides; D002734:Chlorophyll; C037184:chlorophyll b; C106487:flumioxazin; D000077194:Chlorophyll A