Biochemical Specialization of Photosynthetic Cell Layers and Carbon Flow Paths in Suaeda monoica

Abstract

MATERIALS AND METHODS S. monoica Forssk ex. J. F. Gmel was grown in a greenhouse in a sand culture and irrigated with Hoagland solution with 100 mm NaCl.The structure of the three cell layers was investigated using an electron microscope. Leafsections were fixed in 2% glutaraldehyde in 0.15 M phosphate buffer (pH 7.2) and postfixed in 1% OS04 in the same buffer. After dehydration in ethanol the sections were embedded in Epon 812. Activity and localization of the carboxylating (PEP-C and RuBP-C) and of the decarboxylating (NADmalic enzyme) enzymes was tested in extracts of cell layers which ' Abbreviations: PEP-C: phosphoenolpyruvate carboxylase; RuBP-C: ribulose bisphosphate carboxylase; ME: malic enzyme; PGA: phosphoglyceric acid.were mechanically separated. Green succulent mature leaves taken from 3-to 4-year-old plants were used for celi layers separation.

Photoregulation of Phosphoenolpyruvate Carboxylase in Salsola soda L. and Other C4 Plants

“…the outer layer are loosely arranged and apparently play the role of mesophyll cells, as shown in Suaeda monoica (24). This anatomy is quite similar to that of Salsola kali L. (22) and common in a number of succulent Chenopodiaceae (25 MgC92, 0.14 mM NADH, 4.5 units of malate dehydrogenase (pig heart, Sigma) and PEP as specified.…”

Differentiation of cellular and biochemical features of the single‐cell C4 syndrome during leaf development in Bienertia cycloptera (Chenopodiaceae)

“…Their structure changes from having a translucent matrix in the center at young stages to densely packed tubular and lamellated cristae in mature leaves. The latter may simply represent a longitudinal section of elongated cristae, a characteristic common for mitochondria of many NAD-ME species in the Chenopodiaceae family (Laetsch, 1968;Downton, 1971;Voznesenskaya, 1976;Shomer-Ilan et al, 1979;Voznesenskaya and Gamaley, 1986). While the partitioning of mitochondria into the CCC is a relatively early event, accumulation of the decarboxylase occurs after the CCC and the cell are essentially in their mature state.…”

Development of biochemical specialization and organelle partitioning in the single‐cell C4 system in leaves of Borszczowia aralocaspica (Chenopodiaceae)

“…In NAD-ME Kranz type C 4 plants, a similar structure was observed for mitochondria in bundle sheath cells of Amaranthus, Portulaca oleracea L., and Mollugo cerviana (L.) Ser. (Laetsch, 1968(Laetsch, , 1971, while some species of Atriplex, Suaeda, and Salsola have mitochondria with both tubular and lamellated types of cristae (Laetsch, 1968;Downton, 1971;Vosnesenskaja, 1976;Voznesenskaya, 1976;Shomer-Ilan et al 1979;Voznesenskaya and Gamaley, 1986;Fisher et al, 1997). In Bienertia cycloptera, another C 4 species without Kranz anatomy, mitochondria also contained numerous well-developed lamellated cristae (Voznesenskaya et al, 2002) as in C 4 Suaeda species.…”