The role of sugars, hexokinase, and sucrose synthase in the determination of hypoxically induced tolerance to anoxia in tomato roots
| Autor: | Bérénice Ricard, Véronique Germain, Pierre H. Saglio, Philippe Raymond |
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| Přispěvatelé: | ProdInra, Migration, Station de physiologie végétale, Institut National de la Recherche Agronomique (INRA) |
| Jazyk: | angličtina |
| Rok vydání: | 1997 |
| Předmět: |
Hexokinase
Sucrose biology Physiology food and beverages Fructose Plant Science Lactic acid [SDV.GEN.GPL]Life Sciences [q-bio]/Genetics/Plants genetics chemistry.chemical_compound chemistry Biochemistry [SDV.GEN.GPL] Life Sciences [q-bio]/Genetics/Plants genetics Genetics biology.protein Sucrose synthase Glycolysis Energy charge Pyruvate decarboxylase Research Article |
| Zdroj: | Plant Physiology Plant Physiology, American Society of Plant Biologists, 1997, 114 (1), pp.167-175 |
| ISSN: | 0032-0889 1532-2548 |
| Popis: | Hypoxic pretreatment of tomato (Lycopersicon esculentum M.) roots induced an acclimation to anoxia. Survival in the absence of oxygen was improved from 10 h to more than 36 h if external sucrose was present. The energy charge value of anoxic tissues increased during the course of hypoxic acclimation, indicating an improvement of energy metabolism. In acclimated roots ethanol was produced immediately after transfer to anoxia and little lactic acid accumulated in the tissues. In nonacclimated roots significant ethanol synthesis occurred after a 1-h lag period, during which time large amounts of lactic acid accumulated in the tissues. Several enzyme activities, including that of alcohol dehydrogenase, lactate dehydrogenase, pyruvate decarboxylase, and sucrose synthase, increased during the hypoxic pretreatment. In contrast to maize, hexokinase activities did not increase and phosphorylation of hexoses was strongly inhibited during anoxia in both kinds of tomato roots. Sucrose, but not glucose or fructose, was able to sustain glycolytic flux via the sucrose synthase pathway and allowed anoxic tolerance of acclimated roots. These results are discussed in relation to cytosolic acidosis and the ability of tomato roots to survive anoxia. |
| Databáze: | OpenAIRE |
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