title: Evidence that elevated CO2 levels can indirectly increase rhizosphere denitrifier activity.
abstract: We examined the influence of elevated CO2 concentration on denitrifier enzyme activity in wheat rhizoplanes by using controlled environments and solution culture techniques. Potential denitrification activity was from 3 to 24 times higher on roots that were grown under an elevated CO2 concentration of 1,000 micromoles of CO2 mol-1 than on roots grown under ambient levels of CO2. Nitrogen loss, as determined by a nitrogen mass balance, increased with elevated CO2 levels in the shoot environment and with a high NO3- concentration in the rooting zone. These results indicated that aerial CO2 concentration can play a role in rhizosphere denitrifier activity.
authors.affiliation: Department of Vegetable Crops, University of California, Davis 95616, USA.
authors.forename: D R
authors.initials: DR
authors.lastname: Smart
authors.forename: K
authors.initials: K
authors.lastname: Ritchie
authors.forename: J M
authors.initials: JM
authors.lastname: Stark
authors.forename: B
authors.initials: B
authors.lastname: Bugbee
mesh_terms: D000641:Ammonia / Q000378:metabolism; D002245:Carbon Dioxide / Q000378:metabolism / Q000494:pharmacology*; D003470:Culture Media; D004305:Dose-Response Relationship, Drug; D004780:Environment, Controlled; D005308:Fertilizers; D018527:Hydroponics; D009566:Nitrates / Q000494:pharmacology*; D009584:Nitrogen / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism / Q000382:microbiology*; D018520:Plant Shoots / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D012988:Soil Microbiology; D014908:Triticum / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism
chemical_list: D003470:Culture Media; D005308:Fertilizers; D009566:Nitrates; D002245:Carbon Dioxide; D000641:Ammonia; D009584:Nitrogen