c6.6.10 – BVOC emission and ozone uptake along the profile of Populus nigra saplings exposed to high levels of atmospheric ozone

Fares S (1), Oksanen E (2), Nogu’as I (1), Loreto F (1)

(1) CNR – Istituto di Biologia Agroambientale e Forestale, Via Salaria km. 29.300 00016 Monterotondo Scalo (Roma), ITALY; (2) University of Joensuu, P.O.Box 111, FIN-80101, Department of Biology, Finland
Collocazione: c6.6.10 – Tipo Comunicazione: Presentazione orale
6° Congresso SISEF *
Sessione 6: “Poster: “Fattori di stress e strategie di mitigazione”” *

Contatto: Silvano Fares (silva_802000@yahoo.it)

Abstract: Leaves produce BVOCs (Biogenic Volatile Organic Compounds) in response to oxidative stresses e.g. high levels of tropospheric ozone. BVOCs can act as ozone scavenger in the intercellular spaces thus limiting ozone reactions, Reactive Oxygen Species formation, and membranes peroxidation. Two sets of saplings of Populus nigra were grown in climate chambers (one at 100 ppb of ozone and one in ozone-free air). To test whether isoprene influences ozone uptake along the plant profile which reflects ontogenetic differences at leaf level, a) BVOC emission (isoprene and oxygenated compounds), b) ozone uptake and c) physiological parameters (photosynthesis and stomatal conductance) were measured from the apex to the basal leaf). Results showed that isoprene emission decreased in the youngest, apical leaves as compared to the oldest ones. An opposite trend was observed for oxygenated BVOCs, mainly methanol. Ozone inhibited isoprene emission, but stimulated stomatal conductance and, consequently, stomatal ozone uptake, especially in younger leaves. Thus isoprene emission and ozone uptake are not related along the plant profile. Oxygenated compounds increased in the ozone treated plants indicating membrane peroxidation. No differences in photosynthesis were observed in the same conditions, which indicates that oxygenated BVOCs may be a sensitive indicator of injury.

Citazione: Fares S , Oksanen E , Nogu’as I , Loreto F (2007). BVOC emission and ozone uptake along the profile of Populus nigra saplings exposed to high levels of atmospheric ozone . 6° Congresso Nazionale SISEF, Arezzo, 25 – 27 Set 2007, Contributo no. #c6.6.10