title: Independent and parallel recruitment of preexisting mechanisms underlying C₄ photosynthesis.
abstract: C₄ photosynthesis allows increased photosynthetic efficiency because carbon dioxide (CO₂) is concentrated around the key enzyme RuBisCO. Leaves of C₄ plants exhibit modified biochemistry, cell biology, and leaf development, but despite this complexity, C₄ photosynthesis has evolved independently in at least 45 lineages of plants. We found that two independent lineages of C₄ plant, whose last common ancestor predates the divergence of monocotyledons and dicotyledons about 180 million years ago, show conserved mechanisms controlling the expression of genes important for release of CO(2) around RuBisCO in bundle sheath (BS) cells. Orthologous genes from monocotyledonous and dicotyledonous C₃ species also contained conserved regulatory elements that conferred BS specificity when placed into C₄ species. We conclude that these conserved functional genetic elements likely facilitated the repeated evolution of C₄ photosynthesis.
authors.affiliation: Department of Plant Sciences, University of Cambridge, Cambridge, UK.
authors.forename: Naomi J
authors.initials: NJ
authors.lastname: Brown
authors.forename: Christine A
authors.initials: CA
authors.lastname: Newell
authors.forename: Susan
authors.initials: S
authors.lastname: Stanley
authors.forename: Jit E
authors.initials: JE
authors.lastname: Chen
authors.forename: Abigail J
authors.initials: AJ
authors.lastname: Perrin
authors.forename: Kaisa
authors.initials: K
authors.lastname: Kajala
authors.forename: Julian M
authors.initials: JM
authors.lastname: Hibberd
mesh_terms: D020121:5' Untranslated Regions; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism; D002245:Carbon Dioxide / Q000378:metabolism; D031485:Cleome / Q000235:genetics / Q000378:metabolism*; D019143:Evolution, Molecular; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D005966:Glucuronidase / Q000235:genetics / Q000378:metabolism; D008291:Malate Dehydrogenase / Q000235:genetics / Q000378:metabolism; D012275:Oryza / Q000235:genetics / Q000378:metabolism; D010788:Photosynthesis / Q000235:genetics*; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D010944:Plants / Q000235:genetics / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D012045:Regulatory Sequences, Nucleic Acid; D012273:Ribulose-Bisphosphate Carboxylase / Q000378:metabolism*; D014170:Transformation, Genetic; D003313:Zea mays / Q000235:genetics / Q000378:metabolism
chemical_list: D020121:5' Untranslated Regions; D010940:Plant Proteins; D002245:Carbon Dioxide; D008291:Malate Dehydrogenase; C046446:malate dehydrogenase-(oxaloacetate-decarboxylating) (NAD+); C031917:malate dehydrogenase (oxaloacetate-decarboxylating) (NADP+); D005966:Glucuronidase; D012273:Ribulose-Bisphosphate Carboxylase