High C3 photosynthetic capacity and high intrinsic water use efficiency underlies the high productivity of the bioenergy grass Arundo donax

• DOI: 10.1038/srep20694
• Publication Date: 2016-02-10T10:26:10Z
• Authors: Richard J. Webster; Steven M. Driever; Johannes Kromdijk; Justin McGrath; Andrew D. B. Leakey; Katharina Siebke; Tanvir Demetriade...; Steve Bonnage; Tony Peloe; Tracy Lawson; Stephen P. Long
• Keywords: Arundo donax; Photosynthetic capacity; C4 Photosynthesis; Water Use Efficiency

Abstract Arundo donax has attracted interest as a potential bioenergy crop due to high apparent productivity. It uses C3 photosynthesis yet appears competitive with C4 grass biomass feedstock’s and grows in warm conditions where species might be expected that productive. Despite this there been no systematic study of leaf photosynthetic properties. This determines photorespiratory parameters for leaves natural stand A. growing southern Portugal. We hypothesise low light, stomatal limitation small intrinsic water use efficiency unusually low. High rates resulted from capacity both maximum Rubisco ( V c,max 117 μmol CO 2 m −2 s −1 ) ribulose-1:5-bisphosphate limited carboxylation rate J max 213 under light-saturated conditions. Maximum quantum yield light-limited assimilation was also relative other species. Photorespiratory losses were similar the measurement (25%), while (0.25) resulting efficiency. Overall is compared comparable grasses.