title: High C3 photosynthetic capacity and high intrinsic water use efficiency underlies the high productivity of the bioenergy grass Arundo donax.
abstract: Arundo donax has attracted interest as a potential bioenergy crop due to a high apparent productivity. It uses C3 photosynthesis yet appears competitive with C4 grass biomass feedstock's and grows in warm conditions where C4 species might be expected to be that productive. Despite this there has been no systematic study of leaf photosynthetic properties. This study determines photosynthetic and photorespiratory parameters for leaves in a natural stand of A. donax growing in southern Portugal. We hypothesise that A. donax has a high photosynthetic potential in high and low light, stomatal limitation to be small and intrinsic water use efficiency unusually low. High photosynthetic rates in A. donax resulted from a high capacity for both maximum Rubisco (Vc,max 117 μmol CO2 m(-2) s(-1)) and ribulose-1:5-bisphosphate limited carboxylation rate (Jmax 213 μmol CO2 m(-2) s(-1)) under light-saturated conditions. Maximum quantum yield for light-limited CO2 assimilation was also high relative to other C3 species. Photorespiratory losses were similar to other C3 species under the conditions of measurement (25%), while stomatal limitation was high (0.25) resulting in a high intrinsic water use efficiency. Overall the photosynthetic capacity of A. donax is high compared to other C3 species, and comparable to C4 bioenergy grasses.
authors: Institute of Biological Environmental and Rural Sciences, Aberystwyth University, Aberystwyth, U.K.
authors: Richard J
authors: RJ
authors: Webster
authors: Centre for Crop Systems Analysis, Wageningen University, Wageningen, the Netherlands.
authors: Steven M
authors: SM
authors: Driever
authors: Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA.
authors: Johannes
authors: J
authors: Kromdijk
authors: Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA.
authors: Justin
authors: J
authors: McGrath
authors: Department of Plant Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA.|Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA.
authors: Andrew D B
authors: AD
authors: Leakey
authors: Heinz Walz GmbH, Effeltrich, Germany.
authors: Katharina
authors: K
authors: Siebke
authors: LI-COR Biosciences UK Ltd., Cambridge, UK.
authors: Tanvir
authors: T
authors: Demetriades-Shah
authors: ADC BioScientific Ltd., Hoddesdon, UK.
authors: Steve
authors: S
authors: Bonnage
authors: Delta-T Devices Ltd., Cambridge, UK.
authors: Tony
authors: T
authors: Peloe
authors: School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester, U.K.
authors: Tracy
authors: T
authors: Lawson
authors: Department of Plant Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA.|Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA.
authors: Stephen P
authors: SP
authors: Long
mesh_terms: D018533:Biomass; D002245:Carbon Dioxide / Q000378:metabolism; D008027:Light; D010100:Oxygen / Q000378:metabolism; D010788:Photosynthesis / Q000528:radiation effects; D018515:Plant Leaves / Q000378:metabolism; D006109:Poaceae / Q000378:metabolism*; D014867:Water / Q000378:metabolism*
chemical_list: D014867:Water; D002245:Carbon Dioxide; D010100:Oxygen