Biochemical strategies of overwintering in the gall gly larva,Eurosta solidaginis: Effect of low temperature acclimation on the activities of enzymes of intermediary metabolism
The activities of some enzymes of intermediary metabolism, including those involved in glycerol and sorbitol synthesis, were measured in the third instar larvae of the gall fly,Eurosta solidaginis sampled during a controlled (1°C per day decrease) low temperature acclimation of the larvae from 15 to 30°C.
Low temperature acclimation resulted in increased activities of three key enzymes of carbohydrate catabolism: phosphorylase, hexokinase and phosphofructokinase while other enzymes of glycolysis and the Krebs cycle were unaffected by low temperature acclimation.
Other enzymes whose activities were altered by low temperature acclimation included 3-hydroxyacyl-CoA dehydrogenase, an enzyme of fatty acid oxidation, glutamate dehydrogenase and glutamate-pyruvate transaminase. These latter two enzymes are involved in the synthesis of proline and alanine, amino acids which are accumulated in the larvae at low temperatures.
Polyol dehydrogenase activites catalyzing the NADPH-dependent reduction of glyceraldehyde, glucose or fructose were found inE. solidaginis as well as an NADH-dependent sorbitol dehydrogenase. The activities of both sorbitol dehydrogenase and polyol dehydrogenase were increased in the larvae with decreasing acclimation temperature, paralleling the production of sorbitol in these overwintering, freezingtolerant larvae.
The larvae displayed activities of phosphatases utilizing (in descending order of activity) glucose-6-P, fructose-6-P, glucose-1-P, glyceraldehyde-3-P, sorbitol-6-P and glycerol-3-P as substrates. Glyceraldehyde-3-P phosphatase showed a decrease in activity with decreasing acclimation temperature while the C6 sugar phosphate phosphatases showed a decreased activity only at the lowest, −30°C temperature.
The probable pathways for the synthesis of the cryoprotectant polyols, glycerol and sorbitol, inE. solidaginis are outlined and the control of intermediary metabolism during low temperature acclimation in these larvae is discussed.
KeywordsSorbitol Polyol Phosphorylase Hexokinase Glutamate Dehydrogenase
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- Atkinson A, Gatenby AD, Lowe AG (1973) The determination of inorganic phosphate in biological systems. Biochim Biophys Acta 320: 195–204Google Scholar
- Chino H (1960) Enzymatic pathways in the formation of sorbitol and glycerol in the diapausing egg of the silkworm,Bombyx mori. I. On the polyol dehydrogenases. J Insect Physiol 5: 1–15Google Scholar
- Chino H (1961) Enzymatic pathways in the formation of sorbitol and glycerol in the diapausing egg of the silkworm,Bombyx mori. II. On the phosphatases. J Insect Physiol 6: 231–240Google Scholar
- Faulkner P (1958) Polyol dehydrogenase of the silkworm. Biochem J 68: 374–379Google Scholar
- Foster PC, Bailey E (1976) Changes in the activities of the enzymes of hepatic fatty acid oxidation during development of the rat. Biochem J 154: 49–56Google Scholar
- Kageyama T, Takahashi SY, Ohnishi E (1973) Acid phosphatases in the eggs of the silkworm,Bombyx mori: purification and properties. Insect Biochem 3: 373–388Google Scholar
- Male KB, Storey KB (1981) Enzyme activities and isozyme composition of triglyceride, diglyceride and monoglyceride lipase inPeriplaneta americana, Locusta migratoria andPolia adjuncta. Insect Biochem (in press)Google Scholar
- Morrissey RE, Baust JG (1976) The ontogeny of cold tolerance in the gall fly,Eurosta solidagensis. J Insect Physiol 22: 431–437Google Scholar
- Somme L, Velle W (1968) Polyol dehydrogenase in diapausing pupae ofPieris brassicae. J Insect Physiol 14: 135–143Google Scholar
- Storey KB, Bailey E (1978a) The intracellular distribution of enzymes of carbohydrate degradation in the fat body of the adult male cockroach. Insect Biochem 8: 73–79Google Scholar
- Storey KB, Bailey E (1978b) Intracellular distribution of enzymes associated with lipogenesis and gluconeogenesis in fat body of the adult cockroach,Periplaneta. Insect Biochem 8: 125–131Google Scholar
- Storey KB, Baust JG, Storey JM (1981a) Intermediary metabolism during low temperature acclimation in the overwintering gall fly larva,Eurosta solidaginis. J Comp Physiol 144: 183–190Google Scholar
- Storey KB, Baust JG, Beuscher P (1981b) Determination of water “bound” by soluble subcellular components during low temperature acclimation in the gall fly larva,Eurosta solidagensis. Cryobiology 18: 315–321Google Scholar
- Takahashi SY, Kajiura T, Kageyama T, Ohnishi E (1974) Polyol dehydrogenases from silkworm eggs: purification and properties. Insect Biochem 4: 33–45Google Scholar
- Yaginuma T, Yamashita O (1979) NAD-dependent sorbitol dehydrogenase activitiy in relation to the termination of diapause in eggs ofBombyx mori. Insect Biochem 9: 547–553Google Scholar