Development of novel elongated fiber-structure in protoplast cultures of Betula platyphylia and Larix leptolepis

• Published in: In vitro cellular & developmental biology. Plant 2003-03, Vol.39 (2), p.223-228
• Main Authors: Sasamoto, Hamako, Ogita, Shinjiro, Hayashi, Noriko, Wakita, Yohichi, Yokota, Shinso, Yoshizawa, Nobuo
• Format: Article
• Language: English
• Subjects: Betula platyphylia; Larix leptolepis
• ISSN: 1054-5476; 1475-2689
• DOI: 10.1079/IVP2002388

Novel elongated fiber-structures were repeatedly found both in leaf protoplast culture of two clones of Betula platyphylla and in protoplast culture of embryogenic cells of Larix leptolepis. Suboptimum culture conditions for cell division appeared to lead to fiber formation when using multi-well plate culture with varying medium compositions. The suboptimum conditions for cell divisions were brought about by (1) plant growth regulators: auxins and cytokinins; (2) pH: 3.5, 4.5, 5.8; (3) divalent cations: CaCl sub(2) and MgCl sub(2); and (4) sugars: sucrose and mannitol. Divalent cations had the most profound effect on fiber formation. Calcium ions were preferred by Betula and magnesium ions were preferred by Larix. Single fiber-purification and micro-staining methods using a micromanipulator were developed. The fibers fluoresced when stained with Calcofluor White and Aniline Blue, which suggested that they were composed of cell wall component(s), including callose ( beta -1,3-glucan). Electron microscopy showed that fiber bundles of Larix fibers had helical substructures.