title: Phenylpropanoids are key players in the antioxidant defense to ozone of European ash, Fraxinus excelsior.
abstract: Physiological and biochemical responses to ozone (O3) (150 ppb, 8 h day-1, 35 consecutive days) of two Italian provenances (Piedmont and Tuscany) of Fraxinus excelsior L. were evaluated, with special attention to the role of phenylpropanoids. Our results indicate (i) the high O3sensitivity especially of Piedmont provenance (in terms of visible injury, water status, and photosynthetic apparatus); (ii) although the intra-specific sensitivity to O3between provenances differs (mainly due to different stomatal behaviors since only Tuscany plants partially avoided the uptake of the pollutant gas), both provenances showed detoxification and defense mechanisms; (iii) the crucial participation of phenylpropanoids, with a key role played by flavonoids (especially quercitrin): among this class of metabolites, isoquercitrin is the principal player in the lower O3sensitivity of Tuscany plants, together with lignins; (iv) although coumarins (typical compounds of Fraxinus) were severely depressed by O3, isofraxidin was triggered suggesting a key role in reactive oxygen species (ROS) detoxification, as well as trans-chalcone. Furthermore, the different behavior of verbascoside and oleuropein among provenances lead us to speculate on their influence in the tentatively repair or acclimation shown by Piedmont plants at the end of the exposure. Finally, the intra-specific O3sensitivity may be also due to de novo peaks triggered by O3not yet associated to some chemicals.
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: Alessandra
authors.initials: A
authors.lastname: Campanella
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: Giacomo
authors.initials: G
authors.lastname: Lorenzini
authors.affiliation: Department of Agriculture, Food, and Environment, University of Pisa, Via del Borghetto 80, 56124, Pisa, Italy. cristina.nali@unipi.it.
authors.forename: Cristina
authors.initials: C
authors.lastname: Nali
authors.affiliation: Institute of Sustainable Plant Protection, National Research Council, Via Madonna del Piano 10, 50019, Sesto Fiorentino, Firenze, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: Paoletti
mesh_terms: D000393:Air Pollutants / Q000737:chemistry / Q000378:metabolism*; D000975:Antioxidants / Q000737:chemistry / Q000378:metabolism*; D031661:Fraxinus; D007558:Italy; D010126:Ozone / Q000737:chemistry*; D010788:Photosynthesis; D018515:Plant Leaves / Q000737:chemistry; D017382:Reactive Oxygen Species / Q000737:chemistry / Q000378:metabolism*
chemical_list: D000393:Air Pollutants; D000975:Antioxidants; D017382:Reactive Oxygen Species; D010126:Ozone
keywords: Air pollution; Coumarins; Flavonoids; Oleuropein; Oxidative stress; Verbascoside