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S. Seeni, A. Gnanam, Photosynthesis in Cell Suspension Culture of a C4 Plant, Gisekia pharnaceoides L., Plant and Cell Physiology, Volume 24, Issue 6, September 1983, Pages 1033–1041, https://doi.org/10.1093/oxfordjournals.pcp.a076605
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Abstract
Photomixotrophic cell suspension culture was established from the leaf derived callus cells of Gisekia pharnaceoides L., a C4 dicotyledonous weed. The late log phase cells possessed shade-type characters such as low chlorophyll a/b ratio, less pronounced O2 evolution and CO2 fixation, saturation of photosynthetic CO2 fixation at low intensity. The chloroplasts from these cells contained granal stacking with high degree of a very few grana which are characterized by their wide and high degree of stackings.
The predominant labelling of 3-phosphoglyceric acid and sugar phosphates (40% of the total 14C incorporated) during 5 s exposure to 14CO2 in light and subsequent decrease in percentage of 14C in these compounds with increase in exposure time indicated the operation of the C3 pathway in these cells. The simultaneous synthesis of malate (23% of the total 14C incorporated) is related to the much pronounced glycolytic and tricarboxylic acid cycle activities in these cells. The initial proliferation of calli mainly from the zones of vascular supplies in the leaf, high starch content of the cells, presence of large starch grains in all the chloroplasts, activities of Calvin cycle enzymes, heavy labelling of C3 type intermediates and less labelling of aspartate as early photosynthates and rapid accumulation of radioactivity into starch during 14CO2 assimilation indicated that most of the cells in photomixotrophic culture were derived from bundle sheath cells or the leaf cells of Gisekia change their function under culture conditions.
