Xylem water distribution in woody plants visualized with a cryo-scanning electron microscope

Kenichi Yazaki, Mayumi Y. Ogasa, Katsushi Kuroda, Yasuhiro Utsumi, Peter Kitin, Yuzou Sano

研究成果: ジャーナルへの寄稿記事

抄録

A scanning electron microscope installed cryo-unit (cryo-SEM) allows specimen observation at subzero temperatures and has been used for exploring water distribution in plant tissues in combination with freeze fixation techniques using liquid nitrogen (LN2). For woody species, however, preparations for observing the xylem transverse-cut surface involve some difficulties due to the orientation of wood fibers. Additionally, higher tension in the water column in xylem conduits can occasionally cause artifactual changes in water distribution, especially during sample fixation and collection. In this study, we demonstrate an efficient procedure to observe the water distribution within the xylem of woody plants in situ by using a cryostat and cryo-SEM. At first, during sample collection, measuring the xylem water potential should determine whether high tension is present in the xylem conduits. When the xylem water potential is low (< ca. −0.5 MPa), a tension relaxation procedure is needed to facilitate better preservation of the water status in xylem conduits during sample freeze fixation. Next, a watertight collar is attached around the tree stem and filled with LN2 for freeze fixation of the water status of xylem. After harvesting, care should be taken to ensure that the sample is preserved frozen while completing the procedures of sample preparation for observation. A cryostat is employed to clearly expose the xylem transverse-cut surface. In cryo-SEM observations, time adjustment for freeze-etching is required to remove frost dust and accentuate the edge of the cell walls on the viewing surface. Our results demonstrate the applicability of cryo-SEM techniques for the observation of water distribution within xylem at cellular and subcellular levels. The combination of cryo-SEM with non-destructive in situ observation techniques will profoundly improve the exploration of woody plant water flow dynamics.

元の言語英語
記事番号e59154
ジャーナルJournal of Visualized Experiments
2019
発行部数148
DOI
出版物ステータス出版済み - 6 1 2019

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Xylem
Electron microscopes
Electrons
Scanning
Water
Scanning electron microscopy
Observation
Cryostats
Freeze Etching
Plant Dispersal
Nitrogen fixation
Liquid nitrogen
Dust
Cell Wall
Etching
Wood
Nitrogen
Cells
Tissue

All Science Journal Classification (ASJC) codes

  • Neuroscience(all)
  • Chemical Engineering(all)
  • Biochemistry, Genetics and Molecular Biology(all)
  • Immunology and Microbiology(all)

これを引用

Xylem water distribution in woody plants visualized with a cryo-scanning electron microscope. / Yazaki, Kenichi; Ogasa, Mayumi Y.; Kuroda, Katsushi; Utsumi, Yasuhiro; Kitin, Peter; Sano, Yuzou.

:: Journal of Visualized Experiments, 巻 2019, 番号 148, e59154, 01.06.2019.

研究成果: ジャーナルへの寄稿記事

Yazaki, Kenichi ; Ogasa, Mayumi Y. ; Kuroda, Katsushi ; Utsumi, Yasuhiro ; Kitin, Peter ; Sano, Yuzou. / Xylem water distribution in woody plants visualized with a cryo-scanning electron microscope. :: Journal of Visualized Experiments. 2019 ; 巻 2019, 番号 148.
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