Seasonal changes in ice nucleation activity in blueberry stems and effects of cold treatments in vitro
Seasonal changes in ice nucleation activity in blueberry stems and effects of cold treatments in vitro
复制标题
DOI：
10.1016/j.envexpbot.2014.02.010
复制
发表时间：
2014-10-01
影响因子：
5.7
通讯作者：
Ishikawa, Masaya
中科院分区：
文献类型：
--
作者：
Kishimoto, Tadashi;Sekozawa, Yoshihiko;Ishikawa, Masaya
植物内源冰核活性在植物抗寒机制中起着重要作用。然而，只有少数研究涉及植物INA的时空定位，它是如何调节的，它的功能作用是什么。在我们以前的研究中（Kishimoto等人，2014），我们修改了试管方法并开发了用于测量植物标本的INA的高度可重复的测定，并证明了高INA发生在蓝莓茎的越冬树皮组织的细胞壁部分中，并且与茎皮的冷冻行为（细胞外冷冻）很好地对应。在这里，我们遵循的正是季节性变化的干冰核蛋白的两个蓝莓品种和改变干冰核蛋白引起的人工孵化在各种低温。新梢的INA较低，但在7月茎似乎成熟时迅速增加，然后逐渐增加，在第一次秋霜前的10月或11月初达到最大值。在随后的反复霜冻后，茎的INA逐渐下降。这一趋势在抗寒性不同的两个品种之间是一致的。冰核在茎9月至2月增加孵化在0-7摄氏度，而减少冻结到较低的温度。离体培养的结果证实了田间茎冰核蛋白的季节性变化，但其机制仍有待研究。2010-2013年10月，当使用2 mL测定系统测定时，在Woodard当年茎（7.5 mm长）中观察到的最高INA水平（表示为中值冰核温度）为-0.9，与1.0 ℃相似（使用0.5 mL系统时为-1.1，与1.3 ℃相似）。这可能是有史以来报道的生物来源的最高INA之一。(C)2014作者由Elsevier B. V.发布。这是CC BY-NC-ND许可证下的开放获取文章（http：//creativecommons.org/licenses/by-nc-nd/3.0/）。
Ice nucleation activity (INA) of plant intrinsic origins is considered to play important roles in plant cold hardiness mechanisms. Yet, only a few studies have addressed the spatial and temporal localization of plant INA, how it is regulated and what its functional roles are. In our previous study (Kishimoto et al., 2014), we revised a test tube method and developed a highly reproducible assay for measuring INA of plant specimens and demonstrated that high INA occurred in the cell wall fraction of wintering bark tissues of blueberry stems and corresponded well to the freezing behavior (extracellular freezing) of the stem bark. Here, we followed precisely seasonal changes in the stem INA of two blueberry cultivars and alterations in the stem INA caused by artificial incubation at various low temperatures. INA of newly developed shoots was low but increased rapidly by July when the stem became seemingly matured, then gradually increased with the maximum in October or early November just before the first autumnal frost. Following the subsequent recurrent frosts, the stem INA gradually decreased. This tendency was consistent between the two cultivars differing in the level of cold hardiness. INA in the stems of September until February was increased by incubation at 0-7 degrees C whilst decreased by freezing to lower temperatures. The in vitro results corroborate the seasonal changes in the stem INA in the field but the mechanisms remain to be investigated. The highest level of INA (expressed as the median ice nucleation temperature) observed with current year stems (7.5 mm-long) of Woodard in October of 2010-2013 was -0.9 similar to 1.0 degrees C when determined with 2 mL assay system (-1.1 similar to 1.3 degrees C with 0.5 mL system). This may likely be one of the highest INA of biological origins ever reported. (C) 2014 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/).