Effect of local heating and cooling on cambial activity and cell differentiation in the stem of Norway spruce (Picea abies)
Effect of local heating and cooling on cambial activity and cell differentiation in the stem of Norway spruce (Picea abies)
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DOI：
10.1093/aob/mcl050
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发表时间：
2006-06-01
期刊：
影响因子：
4.2
通讯作者：
Oven, Primoz
中科院分区：
文献类型：
--
作者：
Gricar, Jozica;Zupancic, Martin;Oven, Primoz
中心点 背景和目的 研究了加热和冷却对挪威云杉 (Picea abies) 部分茎的形成层活性和细胞分化的影响。 中心点 方法 在春季形成层正常重新激活之前进行加热实验（23-25 摄氏度），并在夏季形成层活动高峰时进行冷却实验（9-11 摄氏度）。通过光学和透射电子显微镜以及紫外显微分光光度法对从活树上采集的组织样本中的形成层、木质部和韧皮部进行了研究。中心点关键结果局部加热 10 天引发韧皮部侧的形成层分裂，20 天后也在木质部侧引发形成层分裂。在对照树中，30 天后开始有规律的形成层活动。在热处理的样品中，发现存在多达 15 个正在分化的早材细胞。形成层对茎冷却的反应不太明显，10 或 20 天后，对照样品和冷处理样品之间没有检测到解剖学差异。 30天后，暴露于冷却的样品中开始形成晚材。此外，几乎没有观察到径向扩张的管胞，形成层仅由五层细胞组成。低温降低了形成层活动，晚材比例下降表明了这一点。在韧皮部方面，在冷却处理和未处理的样品中没有观察到变化。中心点结论加热和冷却可以影响挪威云杉的形成层活性和细胞分化。然而，在超微结构和拓扑化学水平上，次生细胞壁形成和木质化的模式或木质素结构分别没有观察到变化。
center dot Background and Aims The effect of heating and cooling on cambial activity and cell differentiation in part of the stem of Norway spruce (Picea abies) was investigated.center dot Methods A heating experiment (23-25 degrees C) was carried out in spring, before normal reactivation of the cambium, and cooling (9-11 degrees C) at the height of cambial activity in summer. The cambium, xylem and phloem were investigated by means of light- and transmission electron microscopy and UV-microspectrophotometry in tissues sampled from living trees.center dot Key Results Localized heating for 10 d initiated cambial divisions on the phloem side and after 20 d also on the xylem side. In a control tree, regular cambial activity started after 30 d. In the heat-treated sample, up to 15 earlywood cells undergoing differentiation were found to be present. The response of the cambium to stem cooling was less pronounced, and no anatomical differences were detected between the control and cool-treated samples after 10 or 20 d. After 30 d, latewood started to form in the sample exposed to cooling. In addition, almost no radially expanding tracheids were observed and the cambium consisted of only five layers of cells. Low temperatures reduced cambial activity, as indicated by the decreased proportion of latewood. On the phloem side, no alterations were observed among cool-treated and non-treated samples.center dot Conclusions Heating and cooling can influence cambial activity and cell differentiation in Norway spruce. However, at the ultrastructural and topochemical levels, no changes were observed in the pattern of secondary cell-wall formation and lignification or in lignin structure, respectively.