title: Isoprenoids emission in Stipa tenacissima L.: Photosynthetic control and the effect of UV light.
abstract: Fluxes of CO2 and isoprenoids were measured for the first time in Stipa tenacissima L (alfa grass), a perennial tussock grass dominant in the driest areas of Europe. In addition, we studied how those fluxes were influenced by environmental conditions, leaf ontogeny and UV radiation and compared emission rates in two contrasting seasons: summer when plants are mostly inactive and autumn, the growing season in this region. Leaf ontogeny significantly affected both photosynthesis and isoprenoids emission. Isoprene emission was positively correlated with photosynthesis, although a low isoprene emission was detected in brown leaves with a net carbon loss. Moreover, leaves with a significant lower photosynthesis emitted only monoterpenes, while at higher photosynthetic rates also isoprene was produced. Ambient UV radiation uncoupled photosynthesis and isoprene emission. It is speculated that alfa grass represent an exception from the general rules governing plant isoprenoid emitters.
authors.affiliation: Institute of Agro-Environmental & Forest Biology (IBAF), National Research Council (CNR), Via Marconi 2, I-05010 Porano, TR, Italy. Electronic address: gabriele.guidolotti@ibaf.cnr.it.
authors.forename: Gabriele
authors.initials: G
authors.lastname: Guidolotti
authors.affiliation: Department of Biogeography and Global Change, Natural Science Museum (MNCN), Spanish Scientific Council (CSIC), C/Serrano 115 28006 Madrid, Spain.
authors.forename: Ana
authors.initials: A
authors.lastname: Rey
authors.affiliation: Institute of Agro-Environmental & Forest Biology (IBAF), National Research Council (CNR), Via Marconi 2, I-05010 Porano, TR, Italy.
authors.forename: Mauro
authors.initials: M
authors.lastname: Medori
authors.affiliation: Institute of Agro-Environmental & Forest Biology (IBAF), National Research Council (CNR), Via Marconi 2, I-05010 Porano, TR, Italy; Global Change Research Centre, Bělidla 986/4a, 603 00 Brno, Czech Republic.
authors.forename: Carlo
authors.initials: C
authors.lastname: Calfapietra
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D002070:Butadienes; D002244:Carbon; D002245:Carbon Dioxide; D004784:Environmental Monitoring; D005060:Europe; D045782:Hemiterpenes; D039821:Monoterpenes; D010420:Pentanes; D010788:Photosynthesis / Q000502:physiology*; D018515:Plant Leaves; D010944:Plants; D006109:Poaceae / Q000378:metabolism*; D013729:Terpenes / Q000032:analysis*; D014466:Ultraviolet Rays
chemical_list: D000393:Air Pollutants; D002070:Butadienes; D045782:Hemiterpenes; D039821:Monoterpenes; D010420:Pentanes; D013729:Terpenes; C005059:isoprene; D002245:Carbon Dioxide; D002244:Carbon
keywords: Alfa grass; Isoprene; Monoterpene; Semiarid ecosystems; UV radiation