DISRUPTION OF AN ICE-NUCLEATION BARRIER IN COLD HARDY AZALEA BUDS BY SUBLETHAL HEAT-STRESS
DISRUPTION OF AN ICE-NUCLEATION BARRIER IN COLD HARDY AZALEA BUDS BY SUBLETHAL HEAT-STRESS
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DOI：
10.1093/oxfordjournals.aob.a088496
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发表时间：
1992-11-01
期刊：
影响因子：
4.2
通讯作者：
CHALKERSCOTT, L
中科院分区：
文献类型：
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作者：
CHALKERSCOTT, L
冰成核障碍物的成分不明，已知发生在几个寒冷的哈代物种，包括杜鹃花的花蕾。荧光显微镜观察发现，杜鹃花花蕾中存在酚类物质区，可能是冰障。使哈代芽经受45 ℃的亚致死热应激2小时以破坏屏障完整性。处理后2小时，利用差热分析（DTA）观察花的低温光变（LTEs）。暴露于热胁迫的芽的LTE的数量较少和/或发生在较高的温度比对照。DTA后对花朵进行目视分析证实，热应激花朵在比对照花朵更高的温度下被杀死。热胁迫芽也有较低的结果相比，控制冷冻实验表明，控制的抗寒性。
Ice nucleating barriers of undetermined composition are known to occur in floral buds of several cold hardy species, includingAzalea. Fluorescence microscopy indicated the presence of phenolic-nch areas within hardyAzaleaflower buds, which could be ice barriers. Hardy buds were subjected to a sublethal heat stress of 45 °C for 2 h to disrupt barrier integrity. Two hours after treatment the low temperature exotherms (LTEs) of flowers were observed using differential thermal analysis (DTA). The LTEs of buds exposed to heat stress were either fewer in number and/or occurred at higher temperatures than in controls. Visual assay of the flowers following DTA confirmed that heat-stressed flowers were killed at higher temperatures than control flowers. Heat-stressed buds also have lower resultant hardiness compared to controls as demonstrated by controlled freezing experiments.