title: Evolution of C4 photosynthesis in the genus Flaveria: how many and which genes does it take to make C4?
abstract: Selective pressure exerted by a massive decline in atmospheric CO(2) levels 55 to 40 million years ago promoted the evolution of a novel, highly efficient mode of photosynthetic carbon assimilation known as C(4) photosynthesis. C(4) species have concurrently evolved multiple times in a broad range of plant families, and this multiple and parallel evolution of the complex C(4) trait indicates a common underlying evolutionary mechanism that might be elucidated by comparative analyses of related C(3) and C(4) species. Here, we use mRNA-Seq analysis of five species within the genus Flaveria, ranging from C(3) to C(3)-C(4) intermediate to C(4) species, to quantify the differences in the transcriptomes of closely related plant species with varying degrees of C(4)-associated characteristics. Single gene analysis defines the C(4) cycle enzymes and transporters more precisely and provides new candidates for yet unknown functions as well as identifies C(4) associated pathways. Molecular evidence for a photorespiratory CO(2) pump prior to the establishment of the C(4) cycle-based CO(2) pump is provided. Cluster analysis defines the upper limit of C(4)-related gene expression changes in mature leaves of Flaveria as 3582 alterations.
authors.affiliation: Institute of Plant Molecular and Developmental Biology, Heinrich-Heine-University, 40225 Duesseldorf, Germany. gowik@uni-duesseldorf.de
authors.forename: Udo
authors.initials: U
authors.lastname: Gowik
authors.forename: Andrea
authors.initials: A
authors.lastname: Bräutigam
authors.forename: Katrin L
authors.initials: KL
authors.lastname: Weber
authors.forename: Andreas P M
authors.initials: AP
authors.lastname: Weber
authors.forename: Peter
authors.initials: P
authors.lastname: Westhoff
mesh_terms: D000596:Amino Acids / Q000378:metabolism; D005075:Biological Evolution; D002244:Carbon / Q000737:chemistry* / Q000378:metabolism*; D057486:Carbon Cycle / Q000502:physiology; D002245:Carbon Dioxide / Q000378:metabolism; D002247:Carbon Isotopes / Q000737:chemistry / Q000378:metabolism; D002736:Chloroplasts / Q000378:metabolism; D016000:Cluster Analysis; D004579:Electron Transport; D037142:Flaveria / Q000033:anatomy & histology / Q000145:classification / Q000235:genetics* / Q000378:metabolism*; D015870:Gene Expression; D018506:Gene Expression Regulation, Plant; D009584:Nitrogen / Q000378:metabolism; D010788:Photosynthesis / Q000235:genetics* / Q000502:physiology; D010802:Phylogeny; D018515:Plant Leaves / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D012273:Ribulose-Bisphosphate Carboxylase / Q000235:genetics / Q000378:metabolism; D059467:Transcriptome
chemical_list: D000596:Amino Acids; D002247:Carbon Isotopes; D010940:Plant Proteins; D002245:Carbon Dioxide; D002244:Carbon; D012273:Ribulose-Bisphosphate Carboxylase; D009584:Nitrogen