Cryo-scanning electron microscopy reveals that supercooling of overwintering buds of freezing-resistant interspecific hybrid grape 'Yamasachi' is accompanied by partial dehydration
Copyright © 2020 Elsevier GmbH. All rights reserved.
| Veröffentlicht in: | Journal of plant physiology. - 1979. - 253(2020) vom: 09. Okt., Seite 153248 |
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| Weitere Verfasser: | , , , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2020
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| Zugriff auf das übergeordnete Werk: | Journal of plant physiology |
| Schlagworte: | Journal Article Cryo-scanning electron microscopy Dormant compound bud Extraorgan freezing Freezing resistance Grape Supercooling Water 059QF0KO0R |
| Zusammenfassung: | Copyright © 2020 Elsevier GmbH. All rights reserved. Dormant compound buds of grapevines adapt to subfreezing temperatures through a freezing avoidance mechanism. One still-unclear question, however, is whether supercooled water in primordial cells of dormant grape buds are partially dehydrated under subfreezing temperatures. In this study, we used differential thermal analysis (DTA) and cryo-scanning electron microscopy (cryo-SEM) to look for partial dehydration of primordial cells of the freezing-resistant interspecific hybrid cultivar 'Yamasachi'. According to DTA, the freezing temperature of supercooled water in primary buds was not significantly affected by cooling rates between 2 and 5 °C/h; however, maintaining the bud temperature at -15 °C for 12 h followed by cooling at a rate of 5 °C/h depressed the freezing temperature. As revealed by cryo-SEM observation, many wrinkles were present on inner surfaces of walls and outer surfaces of plasma membranes of leaf primordial cells in dormant buds frozen to -15 °C. These results suggest the existence of partial dehydration in dormant-bud primordial cells under subfreezing temperatures. The apparent absence of extracellular ice crystals in bud primordial tissues under subfreezing temperatures suggests that Yamasachi dormant buds adapt to subfreezing temperatures by extraorgan freezing. When we coated primary buds with silicone oil to inhibit freeze dehydration of primordial cells, the freezing temperature of buds was slightly but significantly increased. This result suggests that the partial dehydration of cells promotes bud supercooling capability and has an important role in the freezing adaptation mechanism of grapevines |
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| Beschreibung: | Date Completed 29.03.2021 Date Revised 29.03.2021 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1618-1328 |
| DOI: | 10.1016/j.jplph.2020.153248 |