葡萄(vitisvinifera)茎中木质部导管再充盈最后阶段的活体观察。

PubMed ID
发表日期 2018年Jan月

原始出处 新植物学家
The New phytologist
作者 Brodersen  Craig R  Knipfer  Thorsten  McElrone  Andrew J 

文献标题 葡萄(vitisvinifera)茎中木质部导管再充盈最后阶段的活体观察。
In vivo visualization of the final stages of xylem vessel refilling in grapevine (Vitis vinifera) stems.

文献摘要

在某些植物中,清除栓塞对于恢复水力通路是至关重要的,因为当血管重新连接到蒸腾流时,残余气泡会膨胀。由于缺乏高倍镜下的活体图像,我们对栓塞清除的理解仍停留在理论上。在这里,我们使用活体X射线显微计算机断层摄影术(microCT)结合扫描电子显微镜观察葡萄(vitisvinifera)木质部填充的最后阶段。再填充前,血管壁覆盖一层表面膜,但血管穿孔板开口和血管间凹坑充满空气。首先将气泡从血管间的凹坑中取出,然后是穿孔板内的气泡,这些孔板容纳最后一批最终溶解的空气。穿孔板为二型,与较老的次生木质部中的简单穿孔板相比,窄直径血管中的梯状板更为陡峭,这可能有利于小血管中发生的栓塞的快速填充和分隔,同时促进大血管的高导水性。我们的研究提供了直接的视觉证据,空间和时间动态的最后阶段的栓塞清除。


Embolism removal is critical for restoring hydraulic pathways in some plants, as residual gas bubbles should expand when vessels are reconnected to the transpiration stream. Much of our understanding of embolism removal remains theoretical as a consequence of the lack of in vivo images of the process at high magnification. Here, we used in vivo X-ray micro-computed tomography (microCT) to visualize the final stages of xylem refilling in grapevine (Vitis vinifera) paired with scanning electron microscopy. Before refilling, vessel walls were covered with a surface film, but vessel perforation plate openings and intervessel pits were filled with air. Bubbles were removed from intervessel pits first, followed by bubbles within perforation plates, which hold the last volumes of air which eventually dissolve. Perforation plates were dimorphic, with more steeply angled scalariform plates in narrow diameter vessels, compared with the simple perforation plates in older secondary xylem, which may favor rapid refilling and compartmentalization of embolisms that occur in small vessels, while promoting high hydraulic conductivity in large vessels. Our study provides direct visual evidence of the spatial and temporal dynamics of the final stages of embolism removal.


获取全文 10.1111/nph.14811