Ultrastructure of leaves in C4 Cyperus iria and C3 Carex siderosticta
- 188 Downloads
The ultrastructural aspects ofCyperus iria leaves showing the C4 syndrome and the typical C3 species,Carex siderosticta, in the Cyperaceae family were examined.C. iria exhibited the chlorocyperoid type, showing an unusual Kranz structure with vascular bundles completely surrounded by two bundle sheaths. The cellular components of the inner Kranz bundle sheath cells were similar to those found in the NADP-ME C4 subtype, having centrifugally arranged chloroplasts with greatly reduced grana and numerous starch grains. Their chloroplasts contained convoluted thyla-koids and a weakly-developed peripheral reticulum, although it was extensive mostly in mesophyll cell chloroplasts. The outer mestome bundle sheath layer was sclerenchymatous and generally devoid of organelles, but had unevenly thickened walls. Suberized lamellae were present on its cell walls, and they became polylamellate when traversed by plasmodesmata. Mesophyll cell chloroplasts showed well-stacked grana with small starch grains. InC. siderosticta, vascular bundles were surrounded by the inner mestome sheath and the outer parenchymatous bundle sheath with intercellular spaces. The mestome sheath cells degraded in their early development and remained in a collapsed state, although the suberized lamellae retained polylamellate features. Plastids with a crystalline structure, sometimes membrane-bounded, were found in the epidermal cells. The close interveinal distance was 35–50 μm inC. iria, whereas it was 157–218 μm inC. siderosticta. These ultrastructural characteristics were discussed in relation to their photosynthetic functions.
KeywordsC3Carex siderosticta C4Cyperus iria Cyperaceae Kranz anatomy Leaf ultrastructure mestome sheath
Unable to display preview. Download preview PDF.
- Brown WV (1977) The Kranz syndrome and its subtypes in grass systematics. Mem Torr Bot Club 23: 1–97Google Scholar
- Hatch MD (1987) C4 photosynthesis: a unique blend of modified biochemistry, anatomy and ultrastructure. Bioch et Biophys Acta 895: 81–106Google Scholar
- Laetsch WM (1971) Chloroplast structural relationships in leaves of C4 plants,In MD Hatch, CB Osmond, RO Slayter, eds, Photosynthesis and Photorespiration, Wiley Interscience, New York, pp 323–349Google Scholar
- Li M, Jones MB (1994) Kranzkette, a unique C4 anatomy occurring inCyperus japonicus leaves. Photosynthetica 30: 117–131Google Scholar
- Oh YC (1994) Manual of the Korean Cyperaceae. Vol II. Sungshin Womans University Press, Seoul, pp 23–59Google Scholar
- Rao AP, Rajendrudu G (1989) Net photosynthetic rate in relation to leaf anatomical charateristics of C3, C3-C4 and C4 dicotyledons. Proc Indian Acad Sci 99: 529–537Google Scholar
- Standley LA (1990) Anatomical aspects of the taxonomy of sedges (Carex, Cyperaceae). Can J Bot 24: 1449–1456Google Scholar
- Ueno O (1996) Structural characterization of photosynthetic cells in an amphibious sedge,Eleocharis vivipara, in relation to C3 and C4 metabolism. Planta 199: 382–393Google Scholar
- Ueno O, Samejima M, Koyama T (1989) Distribution and evolution of C4 syndrome inEleocharis, a sedge group inhabiting wet and aquatic environments, based on culm anatomy and carbon isotope ratios. Ann Bot 64: 425–438Google Scholar
- Ueno O, Takeda T (1992) Photosynthetic pathways, ecological characteristics, and the geographical distribution of the Cyperaceae in Japan. Oecologia 89: 195–203Google Scholar
- Ueno O, Takeda T, Murata T (1986) C4 acid decarboxyl-ating enzyme activities of C4 species possessing different Kranz anatomical types in the Cyperaceae. Photosynthetica 20: 111–116Google Scholar