Abstract
Bundle sheath cells from leaves of a variety of C4 species contained little or no carbonic anhydrase activity. The proportion of total leaf carbonic anhydrase in extracts of bundle sheath cells closely reflected the apparent mesophyll cell contamination of bundle sheath cell extracts as measured by the proportion of the mesophyll cell marker enzymes phosphoenolpyruvate carboxylase and pyruvate,Pi dikinase. Values of about 1% or less of the total leaf activity were obtained for all three enzymes. The recorded bundle sheath carbonic anhydrase activity was compared with a calculated upper limit of carbonic anhydrase activity that would still permit efficient functioning of the C4 pathway; that is, a carbonic anhydrase level allowing a sufficiently high steady state [CO2] to suppress photorespiration. Even before correcting for mesophyll cell contamination the activity in bundle sheath cell extracts was substantially less than the calculated upper limit of carbonic anhydrase activity consistent with effective C4 function. The results accord with the notion that a deficiency of carbonic anhydrase in bundle sheath cells is vital for the efficient operation of the C4 pathway.
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Selected References
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- Burnell J. N., Hatch M. D. Photosynthesis in phosphoenolpyruvate carboxykinase-type C4 plants: photosynthetic activities of isolated bundle sheath cells from Urochloa panicoides. Arch Biochem Biophys. 1988 Jan;260(1):177–186. doi: 10.1016/0003-9861(88)90439-0. [DOI] [PubMed] [Google Scholar]
- Chapman K. S., Berry J. A., Hatch M. D. Photosynthetic metabolism in bundle sheath cells of the C4 species Zea mays: Sources of ATP and NADPH and the contribution of photosystem II. Arch Biochem Biophys. 1980 Jul;202(2):330–341. doi: 10.1016/0003-9861(80)90435-x. [DOI] [PubMed] [Google Scholar]
- Chapman K. S., Hatch M. D. Regulation of C4 photosynthesis: mechanism of activation and inactivation of extracted pyruvate, inorganic phosphate dikinase in relation to dark/light regulation. Arch Biochem Biophys. 1981 Aug;210(1):82–89. doi: 10.1016/0003-9861(81)90166-1. [DOI] [PubMed] [Google Scholar]
- Furbank R. T., Hatch M. D. Mechanism of c(4) photosynthesis: the size and composition of the inorganic carbon pool in bundle sheath cells. Plant Physiol. 1987 Dec;85(4):958–964. doi: 10.1104/pp.85.4.958. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hatch M. D. An assat for PEP carboxykinase in crude tissue extracts. Anal Biochem. 1973 Mar;52(1):280–285. doi: 10.1016/0003-2697(73)90350-3. [DOI] [PubMed] [Google Scholar]
- Hatch M. D., Mau S. L. Association of NADP- and NAD-linked malic enzyme acitivities in Zea mays: relation to C4 pathway photosynthesis. Arch Biochem Biophys. 1977 Mar;179(2):361–369. doi: 10.1016/0003-9861(77)90123-0. [DOI] [PubMed] [Google Scholar]
- Jenkins C. L., Burnell J. N., Hatch M. D. Form of inorganic carbon involved as a product and as an inhibitor of c(4) Acid decarboxylases operating in c(4) photosynthesis. Plant Physiol. 1987 Dec;85(4):952–957. doi: 10.1104/pp.85.4.952. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Laing W. A. Regulation of Soybean Net Photosynthetic CO(2) Fixation by the Interaction of CO(2), O(2), and Ribulose 1,5-Diphosphate Carboxylase. Plant Physiol. 1974 Nov;54(5):678–685. doi: 10.1104/pp.54.5.678. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wintermans J. F., de Mots A. Spectrophotometric characteristics of chlorophylls a and b and their pheophytins in ethanol. Biochim Biophys Acta. 1965 Nov 29;109(2):448–453. doi: 10.1016/0926-6585(65)90170-6. [DOI] [PubMed] [Google Scholar]