This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Web of Science (58) Citing Articles via Google Scholar Google Scholar Articles by Burnell, J. N. Articles by Hatch, M. D. Search for Related Content PubMed PubMed Citation Articles by Burnell, J. N. Articles by Hatch, M. D. Agricola Articles by Burnell, J. N. Articles by Hatch, M. D.

Metabolism and Enzymology

Low Bundle Sheath Carbonic Anhydrase Is Apparently Essential for Effective C₄ Pathway Operation

CSIRO, Division of Plant Industry, GPO Box 1600, Canberra City A.C.T. 2601, Australia

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.

This article has been cited by other articles:

				M. Akyildiz, U. Gowik, S. Engelmann, M. Koczor, M. Streubel, and P. Westhoff Evolution and Function of a cis-Regulatory Module for Mesophyll-Specific Gene Expression in the C4 Dicot Flaveria trinervia PLANT CELL, November 1, 2007; 19(11): 3391 - 3402. [Abstract] [Full Text] [PDF]

				J. V. Moroney and R. A. Ynalvez Proposed Carbon Dioxide Concentrating Mechanism in Chlamydomonas reinhardtii Eukaryot. Cell, August 1, 2007; 6(8): 1251 - 1259. [Full Text] [PDF]

				S. G. Tetu, S. K. Tanz, N. Vella, J. N. Burnell, and M. Ludwig The Flaveria bidentis beta-Carbonic Anhydrase Gene Family Encodes Cytosolic and Chloroplastic Isoforms Demonstrating Distinct Organ-Specific Expression Patterns Plant Physiology, July 1, 2007; 144(3): 1316 - 1327. [Abstract] [Full Text] [PDF]

				A. B. Cousins, M. R. Badger, and S. von Caemmerer A Transgenic Approach to Understanding the Influence of Carbonic Anhydrase on C18OO Discrimination during C4 Photosynthesis Plant Physiology, October 1, 2006; 142(2): 662 - 672. [Abstract] [Full Text] [PDF]

				R. C. Leegood C4 photosynthesis: principles of CO2 concentration and prospects for its introduction into C3 plants J. Exp. Bot., April 1, 2002; 53(369): 581 - 590. [Abstract] [Full Text] [PDF]

				K. Parvathi, A.S. Bhagwat, Y. Ueno, K. Izui, and A.S. Raghavendra Illumination Increases the Affinity of Phosphoenolpyruvate Carboxylase to Bicarbonate in Leaves of a C4 Plant, Amaranthus hypochondriacus Plant Cell Physiol., August 1, 2000; 41(8): 905 - 910. [Abstract] [Full Text] [PDF]

				M. Ludwig, S. von Caemmerer, G. Dean Price, M. R. Badger, and R. T. Furbank Expression of Tobacco Carbonic Anhydrase in the C4 Dicot Flaveria bidentis Leads to Increased Leakiness of the Bundle Sheath and a Defective CO2-Concentrating Mechanism Plant Physiology, July 1, 1998; 117(3): 1071 - 1081. [Abstract] [Full Text]

				C. V. Hoang and K. D. Chapman Biochemical and Molecular Inhibition of Plastidial Carbonic Anhydrase Reduces the Incorporation of Acetate into Lipids in Cotton Embryos and Tobacco Cell Suspensions and Leaves Plant Physiology, April 1, 2002; 128(4): 1417 - 1427. [Abstract] [Full Text] [PDF]