title: Responses to ozone pollution of alfalfa exposed to increasing salinity levels.
abstract: Stomatal closure and biosynthesis of antioxidant molecules are two fundamental components of the physiological machinery that lead to stress adaptation during plant's exposure to salinity. Since high stomatal resistance may also contribute in counteracting O(3) damages, we hypothesized that soil salinization may increase O(3) tolerance of crops. An experiment was performed with alfalfa grown in filtered (AOT40=0 in both years) and non-filtered (AOT40=9.7 in 2005 and 6.9 ppm h in 2006) open-top chambers. Alfalfa yield was reduced by O(3) (-33%) only in plants irrigated with salt-free water, while the increasing levels of soil salinity until 1.06 dS m(-1) reduced both stomatal conductance and plant O(3) uptake, thus linearly reducing O(3) effects on yield. Therefore a reliable flux-based model for assessing the effects of O(3) on crop yield should take into account soil salinity.
authors.affiliation: DIAAT, Naples University Federico II, via Università 100, 80055 Portici (NA), Italy.
authors.forename: Albino
authors.initials: A
authors.lastname: Maggio
authors.forename: Fabrizio Quaglietta
authors.initials: FQ
authors.lastname: Chiarandà
authors.forename: Roberto
authors.initials: R
authors.lastname: Cefariello
authors.forename: Massimo
authors.initials: M
authors.lastname: Fagnano
mesh_terms: D000393:Air Pollutants / Q000378:metabolism / Q000633:toxicity*; D018533:Biomass; D018556:Crops, Agricultural / Q000187:drug effects* / Q000502:physiology; D004463:Ecology / Q000379:methods; D007558:Italy; D000455:Medicago sativa / Q000187:drug effects* / Q000502:physiology; D010126:Ozone / Q000378:metabolism / Q000633:toxicity*; D054046:Plant Stomata / Q000378:metabolism; D018526:Plant Transpiration / Q000187:drug effects; D055049:Salt Tolerance; D012621:Seasons; D012965:Sodium Chloride / Q000378:metabolism / Q000633:toxicity*; D014874:Water Pollutants, Chemical / Q000378:metabolism / Q000633:toxicity*
chemical_list: D000393:Air Pollutants; D014874:Water Pollutants, Chemical; D012965:Sodium Chloride; D010126:Ozone