Peroxide-Scavenging Systems during Cold Acclimation of Apple Callus in Culture

作者：Haruyuki Kuroda, Shonosuke Sagisaka, Minoru Asada, Kazuhiko Chiba · 发表于：Plant and Cell Physiology · 年份：1991 · DOI：10.1093/oxfordjournals.pcp.a078126 · 被引用次数：26 · 研究领域：Plant Stress Responses and Tolerance

The relationship between peroxide-scavenging systems and cold acclimation was studied in apple callus in culture during acclimation under artificial conditions. Unacclimated callus did not survive freezing at −10°C, whereas callus acclimated at 0°C exhibited gradually increased resistance to freezing and, after acclimation for 20 days, it survived at temperatures as low as −15−C. During acclimation of callus, there was an immediate and abrupt increase in the activities of ascorbate peroxidase (EC 1.11.1.11), peroxidase (EC 1.11.1.7) and catalase (EC 1.11.1.6), which reached maximum values after acclimation for 10 days, at the same time as the very beginning of the increase in cold hardiness was observed. An increase in the activity of glyceraldehyde-3-phosphate dehydrogenase (EC 1.2.1.12) occurred during the first 5 days of cold treatment. The activities of glucose-6-phosphate dehydrogenase (EC 1.1.1.49), hexokinase (EC 2.7.1.1), glutathione reductase (EC 1.6.4.2), glutathione peroxidase (EC 1.11.1.9) and dehydro-ascorbate reductase (EC 1.8.5.1) increased gradually during the cold treatment. In contrast, the activity of glucosephosphate isomerase (EC 5.3.1.9) decreased gradually during acclimation. Furthermore, during acclimation, the levels of glucose-6-phosphate, fructose-6-phosphate and glucose-1-phosphate increased slowly and steadily, and the levels of GSH and ascorbate remained at consistently higher levels. In addition, acclimation caused marked cytological changes. Th...