Within-tree variability and sample storage effects of bordered pit membranes in xylem of Acer pseudoplatanus
Within-tree variability and sample storage effects of bordered pit membranes in xylem of Acer pseudoplatanus
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DOI：
10.1007/s00468-019-01897-4
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发表时间：
2020-02-01
影响因子：
2.3
通讯作者：
Jansen, Steven
中科院分区：
文献类型：
--
作者：
Kotowska, Martyna M.;Thom, Rebecca;Jansen, Steven
关键信息槭pseudoplatanus木质部组织中的导管间纹孔膜在植物器官内部和之间的厚度不同，并且在脱水和样品制备过程中可能会发生相当大的收缩。导管间纹孔膜已被认为占植物木质部总水力阻力的一半以上，并在干旱引起的水力破坏的脆弱性中发挥重要作用。虽然被认为是与木质部栓塞阻力在种间水平，坑膜结构的变化在不同的器官沿着在一个单一的树内的流动路径之间的厚度仍然在很大程度上未知。利用透射电镜技术研究了悬铃木根、茎、枝、叶柄和叶脉木质部纹孔和纹孔膜特征的树内变异。此外，还测试了酒精处理和脱水等对纹孔膜结构的潜在制备伪影。我们的观察结果表明，在器官之间的有界坑的数量差异，包括坑膜厚度的变化内和跨器官。血管大小与血管间壁厚度呈弱相关，但与小凹膜厚度无显著相关性。木材样品逐渐脱水导致不可逆的收缩坑膜，连同增加的水平的愿望。这些研究结果是相关的探索相似性木质部栓塞抗性植物器官。
Key message Intervessel pit membranes in xylem tissue of Acer pseudoplatanus differ in their thickness both within and across plant organs and may undergo considerable shrinkage during dehydration and sample preparation. Intervessel pit membranes have been suggested to account for more than half of the total xylem hydraulic resistance in plants and play a major role in vulnerability to drought-induced hydraulic failure. While the thickness of intervessel pit membranes was found to be associated with xylem embolism resistance at an interspecific level, variation in pit membrane structure across different organs along the flow path within a single tree remains largely unknown. Based on transmission electron microscopy, we examined intra-tree variation of bordered pit and pit membrane characteristics in xylem of roots, stems, branches, petioles, and leaf veins of Acer pseudoplatanus. Moreover, potential preparation artefacts on pit membrane structure such as alcohol treatment and dehydration were tested. Our observations showed quantitative differences in bordered pits across organs, including variation in pit membrane thickness within and across organs. Vessel size was weakly related to intervessel wall thickness, but not significantly linked to pit membrane thickness. Gradual dehydration of wood samples resulted in irreversible shrinkage of pit membranes, together with increased levels of aspiration. These findings are relevant to explore similarity in xylem embolism resistance across plant organs.