|
|
||||||||
Physiology and Development |
2Laboratory of Anatomy and Morphology, V. L. Komarov Botanical Institute of Russian Academy of Sciences, Prof. Popov Street 2, 197376, St. Petersburg, Russia; 3School of Biological Sciences, Washington State University, Pullman, Washington 99164-4236 USA; 4Department of Baking Technology, Urals State Economic University, Ekaterinburg, Russia
The terrestrial plant Borszczowia aralocaspica (Chenopodiaceae) has recently been shown to contain the entire C4 photosynthesis mechanism within individual, structurally and biochemically polarized chlorenchyma cells rather than in a dual cell system, as has been the paradigm for this type of carbon fixation (Nature 414: 543546, 2001). Analysis of carbon isotope composition and 14CO2 fixation shows that photosynthesis and growth of B. aralocaspica occurs through carbon acquired by C4 photosynthesis. The development of this unique single-cell C4 system in chlorenchyma cells was studied by analysis of young (0.20.3 cm length), intermediate (ca. 0.50.6 cm length), and mature leaves (ca. 3 cm length). The length of chlorenchyma cells approximately doubles from young to intermediate and again from intermediate to the mature leaf stage. In young chlorenchyma cells, there is a single type of chloroplast; the chloroplasts are evenly distributed throughout the cytosol, and all contain starch and rubisco. During leaf development, the activities of phosphoenolpyruvate carboxylase (PEPC; which is cytosolic), rubisco, and pyruvate,Pi dikinase (PPDK) increase on a chlorophyll basis. As leaves mature, chloroplasts differentiate into two distinct structural and biochemical types that are spatially separated into the proximal and distal parts of the cell (the proximal end being closest to the center of the leaf). The early stages of this polarization are observed in intermediate leaves, and the polarization is fully developed in mature leaves. The chloroplasts in the distal ends of the cell have reduced grana and little starch, while those at the proximal ends have well-developed grana and abundant starch. In mature leaves, PPDK is expressed in chloroplasts at the distal end of the cells, while rubisco and adenosine diphosphate glucose (ADPG) pyrophosphorylase are selectively expressed in chloroplasts at the proximal end of the cell. Mitochondrial polarization also occurs during development as nicotinamide-adenine dinucleotide phosphate-malic enzyme (NAD-ME) and the photorespiratory enzyme glycine decarboxylase are expressed in mature but not young leaves and are localized in mitochondria at the proximal end of the cells. The data show that single-cell C4 develops from a single pool of identical organelles that develop differential biochemical functions and spatial partitioning in the cell during maturation.
Key Words: anatomy Borszczowia aralocaspica C4 photosynthesis C4 plants Chenopodiaceae development immunolocalization ultrastructure
This article has been cited by other articles:
![]() |
M. V. Lara, S. Offermann, M. Smith, T. W. Okita, C. S. Andreo, and G. E. Edwards Leaf Development in the Single-Cell C4 System in Bienertia sinuspersici: Expression of Genes and Peptide Levels for C4 Metabolism in Relation to Chlorenchyma Structure under Different Light Conditions Plant Physiology, September 1, 2008; 148(1): 593 - 610. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. V. Lara, S. D.X. Chuong, H. Akhani, C. S. Andreo, and G. E. Edwards Species Having C4 Single-Cell-Type Photosynthesis in the Chenopodiaceae Family Evolved a Photosynthetic Phosphoenolpyruvate Carboxylase Like That of Kranz-Type C4 Species Plant Physiology, October 1, 2006; 142(2): 673 - 684. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. D.X. Chuong, V. R. Franceschi, and G. E. Edwards The Cytoskeleton Maintains Organelle Partitioning Required for Single-Cell C4 Photosynthesis in Chenopodiaceae Species PLANT CELL, September 1, 2006; 18(9): 2207 - 2223. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. V. Voznesenskaya, N. K. Koteyeva, S. D. X. Chuong, H. Akhani, G. E. Edwards, and V. R. Franceschi Differentiation of cellular and biochemical features of the single-cell C4 syndrome during leaf development in Bienertia cycloptera (Chenopodiaceae) Am. J. Botany, November 1, 2005; 92(11): 1784 - 1795. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. V. VOZNESENSKAYA, V. R. FRANCESCHI, and G. E. EDWARDS Light-dependent Development of Single Cell C4 Photosynthesis in Cotyledons of Borszczowia aralocaspica (Chenopodiaceae) during Transformation from a Storage to a Photosynthetic Organ Ann. Bot., February 1, 2004; 93(2): 177 - 187. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |