title: Light to liquid fuel: theoretical and realized energy conversion efficiency of plants using crassulacean acid metabolism (CAM) in arid conditions.
abstract: There has been little attention paid to crassulacean acid metabolism (CAM) as a mechanism for bioenergy crop tolerance to water limitation, in part, because potential yields of CAM plants have been assumed to be lower than those of most commonly studied bioenergy crops. The photochemical efficiency, water-use efficiency (WUE), biomass production, and fuel yield potentials of CAM, C3, and C4 plants that are considered or already in use for bioenergy are reviewed here. The theoretical photosynthetic efficiency of CAM plants can be similar to or greater than other photosynthetic pathways. In arid conditions, the greater WUE of CAM species results in theoretical biomass yield potentials that are 147% greater than C4 species. The realized yields of CAM plants are similar to the theoretical yields that account for water-limiting conditions. CAM plants can potentially be viable commercial bioenergy crops, but additional direct yield measurements from field trials of CAM species are still needed.
authors.affiliation: Voinovich School of Leadership and Public Affairs and Department of Environmental and Plant Biology, Ohio University, Athens, OH, USA daviss6@ohio.edu.
authors.forename: Sarah C
authors.initials: SC
authors.lastname: Davis
authors.affiliation: Energy Biosciences Institute, Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
authors.forename: David S
authors.initials: DS
authors.lastname: LeBauer
authors.affiliation: Energy Biosciences Institute, Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA Department of Plant Biology and Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
authors.forename: Stephen P
authors.initials: SP
authors.lastname: Long
mesh_terms: D027882:Agave / Q000502:physiology* / Q000528:radiation effects; D056804:Biofuels; D018533:Biomass; D002245:Carbon Dioxide / Q000378:metabolism*; D055864:Droughts; D004734:Energy Metabolism; D008027:Light; D008962:Models, Theoretical; D010788:Photosynthesis / Q000502:physiology*; D014867:Water / Q000502:physiology*
chemical_list: D056804:Biofuels; D014867:Water; D002245:Carbon Dioxide
keywords: Agave; bioenergy; biofuel; drought; photochemical efficiency; radiation use efficiency; semi-arid; sisal; water use efficiency.