Expression of Polarity during early Development of Microspore‐derived and Zygotic Embryos of Brassica napus L. cv. Topas
| العنوان: | Expression of Polarity during early Development of Microspore‐derived and Zygotic Embryos of Brassica napus L. cv. Topas |
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| المؤلفون: | W.L.H. van Veenendaal, Gerd Hause, A.A.M. van Lammeren, Bettina Hause |
| المصدر: | Botanica Acta, 107, 407-415 Botanica Acta 107 (1994) |
| بيانات النشر: | Wiley, 1994. |
| سنة النشر: | 1994 |
| مصطلحات موضوعية: | Laboratorium voor Plantencelbiologie, animal structures, Polarity (international relations), microspore culture, Brassica napus, Embryogenesis, Heart shape, pollen culture, Embryo, Plant Science, Biology, Cell biology, Laboratory of Plant Cell Biology, Cell wall, Microspore, embryonic structures, Botany, microspore embryogenesis, symbols, symbols.heraldic_charge, polarity, Central cylinder, Pollen wall |
| الوصف: | Microspore derived (MS-)embryogenesis and zygotic embryogenesis of Brassica napus L. cv. Topas were investigated by light and scanning electron microscopy to reveal the expression of polarity during the transition phase from globular to heart and torpedo shape. During the first 5 days of MS-embryo formation, the cell wall of the former microspores remained intact and a globular mass of cells developed within. Pollen walls ruptured after 5 days of culture; embryos proceeded through heart-shape and torpedo-shape stages within 15 days in a way comparable to, but faster than observed during zygotic embryogenesis. Expression of polarity in globular and elongating MS-embryos was analyzed by detection of the distribution of activated calmodulin as well as of free cytosolic calcium by using confocal scanning laser microscopy, and by the detection of starch. Calmodulin was evenly distributed in globular embryos and only exhibited clear polar distribution in elongated embryos. Free cytosolic Ca2+ accumulated in the protoderm of globular embryos and in the central cylinder of torpedo shaped embryos, but never showed polar distribution. Accumulation of starch granules at the root poles of both sexual as well as MS-embryos, however, indicated polar distribution before the transition from globular to heart shape stage. Since the local rupture of the pollen wall of 6-day-old MS-embryos was never preceded by the decrease of starch at that site, it is likely that the rupture of the pollen wall plays an important role in the local activation of cell metabolism and thus in the determination of the polarity axis in MS-embryos. |
| تدمد: | 0932-8629 |
| الوصول الحر: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::c6a294d3266f8ad7048ee6aa6a0ecfa3Test https://doi.org/10.1111/j.1438-8677.1994.tb00815.xTest |
| حقوق: | CLOSED |
| رقم الانضمام: | edsair.doi.dedup.....c6a294d3266f8ad7048ee6aa6a0ecfa3 |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 09328629 |
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