title: Elevated CO2 and/or ozone modify lignification in the wood of poplars (Populus tremula x alba).
abstract: Trees will have to cope with increasing levels of CO(2) and ozone in the atmosphere. The purpose of this work was to assess whether the lignification process could be altered in the wood of poplars under elevated CO(2) and/or ozone. Young poplars were exposed either to charcoal-filtered air (control), to elevated CO(2) (800 μl l(-1)), to ozone (200 nl l(-1)) or to a combination of elevated CO(2) and ozone in controlled chambers. Lignification was analysed at different levels: biosynthesis pathway activities (enzyme and transcript), lignin content, and capacity to incorporate new assimilates by using (13)C labelling. Elevated CO(2) and ozone had opposite effects on many parameters (growth, biomass, cambial activity, wood cell wall thickness) except on lignin content which was increased by elevated CO(2) and/or ozone. However, this increased lignification was due to different response mechanisms. Under elevated CO(2), carbon supply to the stem and effective lignin synthesis were enhanced, leading to increased lignin content, although there was a reduction in the level of some enzyme and transcript involved in the lignin pathway. Ozone treatment induced a reduction in carbon supply and effective lignin synthesis as well as transcripts from all steps of the lignin pathway and some corresponding enzyme activities. However, lignin content was increased under ozone probably due to variations in other major components of the cell wall. Both mechanisms seemed to coexist under combined treatment and resulted in a high increase in lignin content.
authors.affiliation: Nancy-Université, UMR 1137 Ecologie et Ecophysiologie Forestières, Boulevard des Aiguillettes, BP 70239, F-54506 Vandœuvre lès Nancy, France; INRA, UMR 1137 Ecologie et Ecophysiologie Forestières, F-54280 Champenoux, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Richet
authors.forename: Dany
authors.initials: D
authors.lastname: Afif
authors.forename: Koffi
authors.initials: K
authors.lastname: Tozo
authors.forename: Brigitte
authors.initials: B
authors.lastname: Pollet
authors.forename: Pascale
authors.initials: P
authors.lastname: Maillard
authors.forename: Françoise
authors.initials: F
authors.lastname: Huber
authors.forename: Pierrick
authors.initials: P
authors.lastname: Priault
authors.forename: Jacques
authors.initials: J
authors.lastname: Banvoy
authors.forename: Patrick
authors.initials: P
authors.lastname: Gross
authors.forename: Pierre
authors.initials: P
authors.lastname: Dizengremel
authors.forename: Catherine
authors.initials: C
authors.lastname: Lapierre
authors.forename: Patrick
authors.initials: P
authors.lastname: Perré
authors.forename: Mireille
authors.initials: M
authors.lastname: Cabané
mesh_terms: D002245:Carbon Dioxide / Q000378:metabolism*; D008031:Lignin / Q000378:metabolism*; D010126:Ozone / Q000378:metabolism*; D032107:Populus / Q000254:growth & development / Q000378:metabolism*; D014934:Wood / Q000254:growth & development / Q000378:metabolism*
chemical_list: D002245:Carbon Dioxide; D010126:Ozone; D008031:Lignin