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The effects of elevated atmospheric CO 2 on lipid metabolism in leaves from mature wheat ( Triticum aestivum cv. Hereward) plants
Author(s) -
Williams M.,
Robertson E. J.,
Leech R. M.,
Harwood J. L.
Publication year - 1998
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1046/j.1365-3040.1998.00332.x
Subject(s) - phosphatidylglycerol , labelling , phosphatidylcholine , biology , diacylglycerol kinase , cardiolipin , biochemistry , lipid metabolism , population , fatty acid , metabolism , membrane lipids , phospholipid , botany , membrane , enzyme , demography , protein kinase c , sociology
Winter wheat (Triticum aestivum L. cv. Hereward) plants were grown for 35 d either at 350 μ mol mol –1 CO 2 or at 650 μ mol mol –1 CO 2 . Lipid synthesis was studied in these plants by incubating the 5th leaf on the main stem with [1– 14 C]acetate. Increased CO 2 concentrations did not significantly affect the total incorporation of radiolabel into lipids of whole leaf tissue, but altered the distribution for individual lipid classes. Most noticeable amongst acyl lipids was the reduction in labelling of diacylglycerol and a corresponding increase in the proportion of phosphatidylcholine labelling. In the basal regions, there were similar changes and, in addition, phosphatidylglycerol labelling was particularly increased following growth in an enriched CO 2 atmosphere. The stimulation of labelling of the mitochondrial‐specific lipid, diphosphatidylglycerol, prompted an examination of the mitochondrial population in wheat plants. Mitochondria were localized in intact wheat sections by immunolabelling for the mitochondrial‐specific chaperonin probe. Growth in elevated CO 2 doubled the number of mitochondria compared to growth in ambient CO 2 . Fatty acid labelling was also significantly influenced following growth at elevated CO 2 concentrations. Most noticeable were the changes in 16C:18C ratios for the membrane lipids, phosphatidylcholine, phosphatidylglycerol and monogalactosyldiacylglycerol. These data imply a change in the apportioning of newly synthesized fatty acids between the ‘eukaryotic’ and ‘prokaryotic’ pathways of metabolism under elevated CO 2 .