首页 | 本学科首页   官方微博 | 高级检索  
   检索      


Photosynthesis of Grass Species Differing in Carbon Dioxide Fixation Pathways : VIII. Ultrastructural Characteristics of Panicum Species in the Laxa Group
Authors:Brown R H  Bouton J H  Rigsby L  Rigler M
Institution:Department of Agronomy, University of Georgia, Athens, Georgia 30602.
Abstract:Ultrastructural studies of leaves of seven Panicum species in or closely related to the Laxa group and classified as C3, C4 or C3-C4 intermediate were undertaken to examine features associated with C3 and C4 photosynthesis. The C3 species Panicum rivulare Trin. had few organelles in bundle sheath cell profiles (2 chloroplasts, 1.1 mitochondria, and 0.3 peroxisomes per cell section) compared to an average of 10.6 chloroplasts, 17.7 mitochondria, and 3.2 peroxisomes per bundle sheath cell profile for three C3-C4 species, Panicum milioides Nees ex Trin., Panicum decipiens Nees ex Trin. and Panicum schenckii Hack. However, two other C3 species, Panicum laxum Sw. and Panicum hylaeicum Mez, contained about 0.7, 0.5, and 0.3 as many chloroplasts, mitochondria, and peroxisomes, respectively, as in bundle sheath cell profiles of the C3-C4 species. Chloroplasts and mitochondria in bundle sheath cells were larger than those in mesophyll cells for the C4 species Panicum prionitis Griseb. and the C3-C4 species, but in C3 species the organelles were similar in size or were smaller in the bundle sheath cells. The C3-C4 species and P. laxum and P. hylaeicum exhibited an unusually close association of organelles in bundle sheath cells with mitochondria frequently surrounded in profile by chloroplasts. The high concentrations in bundle sheath cells of somewhat larger organelles than in mesophyll cells correlates with the reduced photorespiration of the C3-C4 species.
Keywords:
本文献已被 PubMed 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号