title: Lessons from engineering a single-cell C(4) photosynthetic pathway into rice.
abstract: The transfer of C(4) plant traits into C(3) plants has long been a strategy for improving the photosynthetic performance of C(3) plants. The introduction of a pathway mimicking the C(4) photosynthetic pathway into the mesophyll cells of C(3) plants was only a realistic approach when transgenic technology was sufficiently well developed and widely adopted. Here an attempt to introduce a single-cell C(4)-like pathway in which CO(2) capture and release occur in the mesophyll cell, such as the one found in the aquatic plant Hydrilla verticillata (L.f.) Royle, into rice (Oryza sativa L.) is described. Four enzymes involved in this pathway were successfully overproduced in the transgenic rice leaves, and 12 different sets of transgenic rice that overproduce these enzymes independently or in combination were produced and analysed. Although none of these transformants has yet shown dramatic improvements in photosynthesis, these studies nonetheless have important implications for the evolution of C(4) photosynthetic genes and their metabolic regulation, and have shed light on the unique aspects of rice physiology and metabolism. This article summarizes the lessons learned during these attempts to engineer single-cell C(4) rice.
authors: Photobiology and Photosynthesis Research Unit, National Institute of Agrobiological Sciences, Kannondai, Tsukuba 305-8602, Japan. mmiyao@affrc.go.jp
authors: Mitsue
authors: M
authors: Miyao
authors: Chisato
authors: C
authors: Masumoto
authors: Shin-Ichi
authors: S
authors: Miyazawa
authors: Hiroshi
authors: H
authors: Fukayama
mesh_terms: D002245:Carbon Dioxide / Q000378:metabolism; D002736:Chloroplasts / Q000201:enzymology / Q000235:genetics / Q000502:physiology; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D005818:Genetic Engineering / Q000379:methods*; D031321:Hydrocharitaceae / Q000201:enzymology / Q000235:genetics; D008291:Malate Dehydrogenase / Q000235:genetics / Q000378:metabolism; D050538:Malate Dehydrogenase (NADP+) / Q000235:genetics / Q000378:metabolism; D058503:Mesophyll Cells / Q000201:enzymology / Q000378:metabolism / Q000502:physiology; D012275:Oryza / Q000201:enzymology / Q000235:genetics* / Q000502:physiology*; D019764:Phosphoenolpyruvate Carboxykinase (ATP) / Q000235:genetics / Q000378:metabolism; D010788:Photosynthesis / Q000235:genetics / Q000502:physiology*; D018515:Plant Leaves / Q000201:enzymology / Q000235:genetics / Q000502:physiology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D018520:Plant Shoots / Q000201:enzymology / Q000235:genetics / Q000502:physiology; D030821:Plants, Genetically Modified / Q000201:enzymology / Q000235:genetics / Q000502:physiology; D011772:Pyruvate, Orthophosphate Dikinase / Q000235:genetics / Q000378:metabolism; D019289:Pyruvic Acid / Q000378:metabolism
chemical_list: D010940:Plant Proteins; D002245:Carbon Dioxide; D019289:Pyruvic Acid; D008291:Malate Dehydrogenase; C031917:malate dehydrogenase (oxaloacetate-decarboxylating) (NADP+); D050538:Malate Dehydrogenase (NADP+); D011772:Pyruvate, Orthophosphate Dikinase; D019764:Phosphoenolpyruvate Carboxykinase (ATP)