title: A hypothesis on the evolution of isoprenoid emission by oaks based on the correlation between emission type and Quercus taxonomy.
abstract: We show that Mediterranean oaks that emit isoprene, monoterpenes or no isoprenoids belong to different subgenera as indicated by morpho-taxonomy and molecular genetics. On the other hand, oaks from North America and Asia that are taxonomically similar to the Mediterranean monoterpene emitter Q. ilex emit isoprene only. We surmise that isoprene emission is a genetic character which evolved ancestrally in the oak genus since this is the prevalent emission type in oaks widespread around the world and adapted to different environments. This ancestral character may have been either lost or modified in more recent clades such as those originating the Mediterranean oaks. If our hypothesis is correct then the taxonomy of European oaks is validated by this independent trait. Isoprenoid emission could serve as a chemo-taxonomical marker and could be used to reconstruct the phylogeny of oaks in association with molecular markers.
authors.affiliation: CNR-Istituto di Biochimica ed Ecofisiologia Vegetali, Via Salaria Km. 29,300, 00016 Monterotondo Scalo, Roma, Italy Fax: +39-6-9064492; e-mail: franci@nserv.icmat.mlib.cnr.it, , , , , , IT.
authors.forename: Francesco
authors.initials: F
authors.lastname: Loreto
authors.affiliation: CNR-Istituto per l'Inquinamento Atmosferico, Via Salaria Km. 29,300, 00016 Monterotondo Scalo, Roma, Italy, , , , , , IT.
authors.forename: Paolo
authors.initials: P
authors.lastname: Ciccioli
authors.affiliation: CNR-Istituto per l'Inquinamento Atmosferico, Via Salaria Km. 29,300, 00016 Monterotondo Scalo, Roma, Italy, , , , , , IT.
authors.forename: Enzo
authors.initials: E
authors.lastname: Brancaleoni
authors.affiliation: Universita' della Tuscia, Dip. Scienze Ambientali, Viterbo, Italy, , , , , , IT.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Valentini
authors.affiliation: Universita' "La Sapienza", Dip. Biologia Vegetale, 00100 Roma, Italy, , , , , , IT.
authors.forename: Manuela
authors.initials: M
authors.lastname: De Lillis
authors.affiliation: European Union Joint Research Centre, 21020 Ispra, Varese, Italy, , , , , , IT.
authors.forename: Olav
authors.initials: O
authors.lastname: Csiky
authors.affiliation: European Union Joint Research Centre, 21020 Ispra, Varese, Italy, , , , , , IT.
authors.forename: Guenther
authors.initials: G
authors.lastname: Seufert
keywords: Evolution; Isoprenoid emission; Key words Chemo-taxonomy; Quercus