Planta. 1982 Jun;155(1):8-16. doi: 10.1007/BF00402925.
Activity of enzymes of carbon metabolism during the induction of Crassulacean acid metabolism in Mesembryanthemum crystallinum L.
Planta
J A Holtum, K Winter
Affiliations
Affiliations
- Department of Environmental Biology, Research School of Biological Sciences, Australian National University, P.O. Box 475, 2601, Canberra City, A.C.T., Australia.
PMID: 24271620
DOI: 10.1007/BF00402925
Abstract
The maximum extractable activities of twenty-one photosynthetic and glycolytic enzymes were measured in mature leaves of Mesembryanthemum crystallinum plants, grown under a 12 h light 12 h dark photoperiod, exhibiting photosynthetic characteristics of either a C3 or a Crassulacean acid metabolism (CAM) plant. Following the change from C3 photosynthesis to CAM in response to an increase in the salinity of in the rooting medium from 100 mM to 400 mM NaCl, the activity of phosphoenolpyruvate (PEP) carboxylase (EC 4.1.1.31) increased about 45-fold and the activities of NADP malic enzyme (EC 1.1.1.40) and NAD malic enzyme (EC 1.1.1.38) increased about 4- to 10-fold. Pyruvate, Pi dikinase (EC 2.7.9.1) was not detected in the non-CAM tissue but was present in the CAM tissue; PEP carboxykinase (EC 4.1.1.32) was detected in neither tissue. The induction of CAM was also accompanied by large increases in the activities of the glycolytic enzymes enolase (EC 4.2.1.11), phosphoglyceromutase (EC 2.7.5.3), phosphoglycerate kinase (EC 2.7.2.3), NAD glyceraldehyde-3-phosphate dehydrogenase (EC 1.2.1.12), and glucosephosphate isomerase (EC 2.6.1.2). There were 1.5- to 2-fold increases in the activities of NAD malate dehydrogenase (EC 1.1.1.37), alanine and aspartate aminotransferases (EC 2.6.1.2 and 2.6.1.1 respectively) and NADP glyceraldehyde-3-phosphate dehydrogenase (EC 1.2.1.13). The activities of ribulose-1,5-bisphosphate (RuBP) carboxylase (EC 4.1.1.39), fructose-1,6-bisphosphatase (EC 3.1.3.11), phosphofructokinase (EC 2.7.1.11), hexokinase (EC 2.7.1.2) and glucose-6-phosphate dehydrogenase (EC 1.1.1.49) remained relatively constant. NADP malate dehydrogenase (EC 1.1.1.82) activity exhibited two pH optima in the non-CAM tissue, one at pH 6.0 and a second at pH 8.0. The activity at pH 8.0 increased as CAM was induced. With the exceptions of hexokinase and glucose-6-phosphate dehydrogenase, the activities of all enzymes examined in extracts from M. crystallinum exhibiting CAM were equal to, or greater than, those required to sustain the maximum rates of carbon flow during acidification and deacidification observed in vivo. There was no day-night variation in the maximum extractable activities of phosphoenolpyruvate carboxylase, NADP malic enzyme, NAD malic enzyme, fructose-1,6-bisphosphatase and NADP malate dehydrogenase in leaves of M. crystallinum undergoing CAM.
References
- Planta. 1973 Mar;114(1):75-85 - PubMed
- Plant Physiol. 1978 Mar;61(3):469-71 - PubMed
- Planta. 1979 Jan;144(2):143-51 - PubMed
- Plant Physiol. 1977 Mar;59(3):455-8 - PubMed
- Plant Physiol. 1980 May;65(5):792-6 - PubMed
- Anal Biochem. 1977 Mar;78(1):66-75 - PubMed
- Anal Biochem. 1973 Mar;52(1):280-5 - PubMed
- Biochem J. 1970 Sep;119(2):273-80 - PubMed
- Plant Physiol. 1949 Jan;24(1):1-15 - PubMed
- Planta. 1979 Dec;147(3):210-5 - PubMed
- Plant Physiol. 1975 Jul;56(1):8-12 - PubMed
- Plant Physiol. 1982 Feb;69(2):300-7 - PubMed
- Plant Physiol. 1979 Jun;63(6):1029-32 - PubMed
- Arch Biochem Biophys. 1973 May;156(1):195-206 - PubMed
- Biochim Biophys Acta. 1975 Jul 8;396(1):141-8 - PubMed
- Plant Physiol. 1975 Nov;56(5):605-7 - PubMed
- Plant Physiol. 1972 Feb;49(2):256-9 - PubMed
Publication Types