植物学报2018，Vol.53Issue(2)：203-211,9.DOI:10.11983/CBB17026
女贞和冬青卫矛叶片低温下胞外结冰模式的热力学新证据
New Evidence for the Mode of Extracellular Freezing in Leaves of Ligustrum lucidum and Euonymus japonicus under Low Temperatures
摘要
Abstract
The freezing mode,namely intracellular or extracellular freezing,is vital to plants under low temperatures,but direct evidence of extracellular freezing,especially from thermodynamic experiments,are still very rare.In this paper,we examined exotherms from differential thermal analyses as well as microscopic observations in detached leaves from Ligustrum lucidum and Euonymus japonicus during cooling.We show new evidence of extracellular freezing during cooling.The living leaves of the two plants consistently exhibited biphasic freezing exotherms (i.e.,an initial small exotherm followed by a slow but much larger exotherm).In contrast,the freeze-killed leaves,as well as the filter paper drenched with extracted tissue solutions from leaves of the two plants,exhibited just one fast and large exotherm typical for a single-phase freezing.Extensive colourless extracellular ice crystals were seen under the microscope,with cells dehydrated and shrunken but with no leakage of coloured cell solution,which agreed with the thermal analysis.The experiments presented a new approach and deeper insight into the mechanisms of freezing stress and injury in higher plants.关键词
女贞/冬青卫矛/冰冻胁迫/差热分析/胞外结冰Key words
Ligustrum lucidum/Euonymus japonicus/freezing stress/differential thermal analysis/extracellular freezing引用本文复制引用
于瑞凤,朱建军..女贞和冬青卫矛叶片低温下胞外结冰模式的热力学新证据[J].植物学报,2018,53(2):203-211,9.基金项目
国家自然科学基金(No.31371540,No.31260080)和山东省自然科学基金(No.ZR2012CM007) （No.31371540,No.31260080）
