首页 | 本学科首页   官方微博 | 高级检索  
   检索      


Elevated CO2 and ozone reduce nitrogen acquisition by Pinus halepensis from its mycorrhizal symbiont
Authors:Kytöviita Minna-Maarit  Le Thiec Didier  Dizengremel Pierre
Institution:Department of Biology, Oulu University, PL 3000, FIN-90401 Oulu, Finland;Laboratoire de Biologie Forestière, AssociéINRA, UniversitéHenri Poincaré-Nancy I, BP 239, F-54506 Vandoeuvre-lès-Nancy, France;INRA-Centre de Recherches Forestières, UnitéEcophysiologie Forestière-Laboratoire de Pollution Atmosphérique, F-54280 Champenoux, France
Abstract:The effects of 700 μmol mol−1 CO2 and 200 nmol mol−1 ozone on photosynthesis in Pinus halepensis seedlings and on N translocation from its mycorrhizal symbiont, Paxillus involutus, were studied under nutrient-poor conditions. After 79 days of exposure, ozone reduced and elevated CO2 increased net assimilation rate. However, the effect was dependent on daily accumulated exposure. No statistically significant differences in total plant mass accumulation were observed, although ozone-treated plants tended to be smaller. Changes in atmospheric gas concentrations induced changes in allocation of resources: under elevated ozone, shoots showed high priority over roots and had significantly elevated N concentrations. As a result of different shoot N concentration and net carbon assimilation rates, photosynthetic N use efficiency was significantly increased under elevated CO2 and decreased under ozone. The differences in photosynthesis were mirrored in the growth of the fungus in symbiosis with the pine seedlings. However, exposure to CO2 and ozone both reduced the symbiosis-mediated N uptake. The results suggest an increased carbon cost of symbiosis-mediated N uptake under elevated CO2, while under ozone, plant N acquisition is preferentially shifted towards increased root uptake.
Keywords:
本文献已被 PubMed 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号