C(4) photosynthesis: principles of CO(2) concentration and prospects for its introduction into C(3) plants.
C(4) photosynthesis has a number of distinct properties that enable the capture of CO(2) and its concentration in the vicinity of Rubisco, so as to reduce the oxygenase activity of Rubisco, and hence the rate of photorespiration. The aim of this review is to discuss the properties of this CO(2)-concentrating mechanism, and thus to indicate the minimum requirements of any genetically-engineered system. In particular, the Kranz leaf anatomy of C(4) photosynthesis and the division of the C(4)-cycle between two cell types involves intercellular co-operation that requires modifications in regulation and transport to make C(4) photosynthesis work. Some examples of these modifications are discussed. Comparisons are made with the C(4)-type photosynthesis found in single-celled C(4)-type CO(2)-concentrating mechanisms, such as that found in the aquatic plant, Hydrilla verticillata and the single-celled C(4) system found in the terrestrial chenopod Borszczowia aralocaspica. The outcome of recent attempts to engineer C(4) enzymes into C(3) plants is discussed.
Leegood
Richard C
RC
Robert Hill Institute and Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, UK. r.leegood@shef.ac.uk
D000255:Adenosine Triphosphate / Q000378:metabolism; D002245:Carbon Dioxide / Q000378:metabolism*; D002736:Chloroplasts / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism; D010730:Phosphoenolpyruvate Carboxylase / Q000378:metabolism; D010788:Photosynthesis / Q000502:physiology*; D045322:Photosynthetic Reaction Center Complex Proteins / Q000378:metabolism; D010944:Plants / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified; D012273:Ribulose-Bisphosphate Carboxylase / Q000378:metabolism
D045322:Photosynthetic Reaction Center Complex Proteins; D002245:Carbon Dioxide; D000255:Adenosine Triphosphate; D010730:Phosphoenolpyruvate Carboxylase; D012273:Ribulose-Bisphosphate Carboxylase; D010100:Oxygen