title: Biochemical acclimation, stomatal limitation and precipitation patterns underlie decreases in photosynthetic stimulation of soybean (Glycine max) at elevated [CO₂] and temperatures under fully open air field conditions.
abstract: The net effect of elevated [CO2] and temperature on photosynthetic acclimation and plant productivity is poorly resolved. We assessed the effects of canopy warming and fully open air [CO2] enrichment on (1) the acclimation of two biochemical parameters that frequently limit photosynthesis (A), the maximum carboxylation capacity of Rubisco (Vc,max) and the maximum potential linear electron flux through photosystem II (Jmax), (2) the associated responses of leaf structural and chemical properties related to A, as well as (3) the stomatal limitation (l) imposed on A, for soybean over two growing seasons in a conventionally managed agricultural field in Illinois, USA. Acclimation to elevated [CO2] was consistent over two growing seasons with respect to Vc,max and Jmax. However, elevated temperature significantly decreased Jmax contributing to lower photosynthetic stimulation by elevated CO2. Large seasonal differences in precipitation altered soil moisture availability modulating the complex effects of elevated temperature and CO2 on biochemical and structural properties related to A. Elevated temperature also reduced the benefit of elevated [CO2] by eliminating decreases in stomatal limitation at elevated [CO2]. These results highlight the critical importance of considering multiple environmental factors (i.e. temperature, moisture, [CO2]) when trying to predict plant productivity in the context of climate change.
authors.affiliation: Department of Environmental and Plant Biology, Ohio University, Athens, OH 45701, USA. Electronic address: rosentha@ohio.edu.
authors.forename: David M
authors.initials: DM
authors.lastname: Rosenthal
authors.affiliation: Department of Plant Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
authors.forename: Ursula M
authors.initials: UM
authors.lastname: Ruiz-Vera
authors.affiliation: Department of Plant Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
authors.forename: Matthew H
authors.initials: MH
authors.lastname: Siebers
authors.affiliation: Department of Plant Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
authors.forename: Sharon B
authors.initials: SB
authors.lastname: Gray
authors.affiliation: Department of Plant Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Global Change and Photosynthesis Research Unit, USDA Agricultural Research Service, Urbana, IL 61801, USA; Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
authors.forename: Carl J
authors.initials: CJ
authors.lastname: Bernacchi
authors.affiliation: Department of Plant Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Global Change and Photosynthesis Research Unit, USDA Agricultural Research Service, Urbana, IL 61801, USA; Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA. Electronic address: d-ort@illinois.edu.
authors.forename: Donald R
authors.initials: DR
authors.lastname: Ort
mesh_terms: D000064:Acclimatization; D002245:Carbon Dioxide / Q000378:metabolism*; D057231:Climate Change; D006358:Hot Temperature; D009584:Nitrogen / Q000378:metabolism; D010788:Photosynthesis; D054046:Plant Stomata / Q000502:physiology; D011891:Rain; D012273:Ribulose-Bisphosphate Carboxylase / Q000378:metabolism; D012987:Soil / Q000737:chemistry; D013025:Glycine max / Q000378:metabolism*; D014867:Water / Q000032:analysis
chemical_list: D012987:Soil; D014867:Water; D002245:Carbon Dioxide; D012273:Ribulose-Bisphosphate Carboxylase; D009584:Nitrogen
keywords: Carboxylation; J(max); Photosynthetic nitrogen use efficiency; RuBP regeneration; Stomatal limitation; V(c,max)