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Title: Photosynthetic carbon fixation characteristics of fruiting structures of Brassica campestris L

Abstract

Activities of key enzymes of the Calvin cycle and C/sub 4/ metabolism, rates of CO/sub 2/ fixation, and the initial products of photosynthetic /sup 14/CO/sub 2/ fixation were determined in the podwall, seed coat (fruiting structures), and the subtending leaf (leaf below a receme) of Brassica campestris L. cv Toria. Compared to activities of ribulose-1,5-bisphosphate carboxylase and other Calvin cycle enzymes, e.g. NADP-glyceraldehyde-3-phosphate-dehydrogenase and ribulose-5-phosphate kinase, the activities of phosphoenol pyruvate carboxylase and other enzymes of C/sub 4/ metabolism, viz. NADP-malate dehydrogenase, NADP-malic enzyme, glutamate pyruvate transaminase, and glutamate oxaloacetate transaminase, were generally much higher in seed than in podwall and leaf. Podwall and leaf were comparable to each other. Pulse-chase experiments showed that in seed the major product of /sup 14/CO/sub 2/ assimilation was malate (in short time), whereas in podwall and leaf, the label initially appeared in 3-PGA. With time, the label moved to sucrose. In contrast to legumes, Brassica pods were able to fix net CO/sub 2/ during light. However, respiratory losses were very high during the dark period.

Authors:
; ;
Publication Date:
Research Org.:
Haryana Agricultural Univ., Hisar, India
OSTI Identifier:
5900356
Resource Type:
Journal Article
Resource Relation:
Journal Name: Plant Physiol.; (United States); Journal Volume: 83:4
Country of Publication:
United States
Language:
English
Subject:
59 BASIC BIOLOGICAL SCIENCES; BRASSICA; CARBON DIOXIDE FIXATION; ENZYME ACTIVITY; BIOLOGICAL PATHWAYS; BIOSYNTHESIS; CARBON 14 COMPOUNDS; CARBOXYLASE; ENZYMES; LEAVES; METABOLISM; NUCLEOTIDE DEHYDROGENASES; PHOTOSYNTHESIS; SEEDS; TRACER TECHNIQUES; CARBON-CARBON LYASES; CARBOXY-LYASES; CHEMICAL REACTIONS; FOOD; ISOTOPE APPLICATIONS; LABELLED COMPOUNDS; LYASES; OXIDOREDUCTASES; PHOTOCHEMICAL REACTIONS; PLANTS; SYNTHESIS; VEGETABLES; 551001* - Physiological Systems- Tracer Techniques

Citation Formats

Singal, H.R., Sheoran, I.S., and Singh, R. Photosynthetic carbon fixation characteristics of fruiting structures of Brassica campestris L. United States: N. p., 1987. Web. doi:10.1104/pp.83.4.1043.
Singal, H.R., Sheoran, I.S., & Singh, R. Photosynthetic carbon fixation characteristics of fruiting structures of Brassica campestris L. United States. doi:10.1104/pp.83.4.1043.
Singal, H.R., Sheoran, I.S., and Singh, R. 1987. "Photosynthetic carbon fixation characteristics of fruiting structures of Brassica campestris L". United States. doi:10.1104/pp.83.4.1043.
@article{osti_5900356,
title = {Photosynthetic carbon fixation characteristics of fruiting structures of Brassica campestris L},
author = {Singal, H.R. and Sheoran, I.S. and Singh, R.},
abstractNote = {Activities of key enzymes of the Calvin cycle and C/sub 4/ metabolism, rates of CO/sub 2/ fixation, and the initial products of photosynthetic /sup 14/CO/sub 2/ fixation were determined in the podwall, seed coat (fruiting structures), and the subtending leaf (leaf below a receme) of Brassica campestris L. cv Toria. Compared to activities of ribulose-1,5-bisphosphate carboxylase and other Calvin cycle enzymes, e.g. NADP-glyceraldehyde-3-phosphate-dehydrogenase and ribulose-5-phosphate kinase, the activities of phosphoenol pyruvate carboxylase and other enzymes of C/sub 4/ metabolism, viz. NADP-malate dehydrogenase, NADP-malic enzyme, glutamate pyruvate transaminase, and glutamate oxaloacetate transaminase, were generally much higher in seed than in podwall and leaf. Podwall and leaf were comparable to each other. Pulse-chase experiments showed that in seed the major product of /sup 14/CO/sub 2/ assimilation was malate (in short time), whereas in podwall and leaf, the label initially appeared in 3-PGA. With time, the label moved to sucrose. In contrast to legumes, Brassica pods were able to fix net CO/sub 2/ during light. However, respiratory losses were very high during the dark period.},
doi = {10.1104/pp.83.4.1043},
journal = {Plant Physiol.; (United States)},
number = ,
volume = 83:4,
place = {United States},
year = 1987,
month = 4
}