RELATIONSHIP BETWEEN ENDOPOLYPLOIDY AND CELL-SIZE IN EPIDERMAL TISSUE OF ARABIDOPSIS
RELATIONSHIP BETWEEN ENDOPOLYPLOIDY AND CELL-SIZE IN EPIDERMAL TISSUE OF ARABIDOPSIS
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DOI：
10.1105/tpc.5.11.1661
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发表时间：
1993-11-01
期刊：
影响因子：
11.6
通讯作者：
COLEMAN, AW
中科院分区：
文献类型：
--
作者：
MELARAGNO, JE;MEHROTRA, B;COLEMAN, AW
拟南芥茎和叶表皮细胞的单个细胞核中的DNA的相对量进行了测量microspectrofluorometrically使用表皮果皮。通过与根尖有丝分裂细胞核的比较来评估每个细胞核的相对倍性水平。在表皮细胞中明显可见规则的内多倍性。保卫细胞核含有与分裂的根细胞相当的DNA水平，2C水平（即，核DNA的一个未复制拷贝）。叶毛状体细胞核的4C、8 C、16 C、32 C和64 C倍性水平升高，它们的细胞学表明多倍性代表多线性的一种形式。茎表皮细胞核为2C、4C、8 C，叶表皮细胞核为2C、4C、8 C、16 C。表皮铺装层细胞的形态测定显示，细胞核DNA水平和细胞大小之间成正比。对发育过程的考虑表明，最高倍性水平的细胞是发育最古老的;因此，表皮组织的发育模式可以从细胞的倍性模式中读取。这一观察结果与气孔间距的理论有关，并为内多倍体/多线现象的遗传分析提供了机会。
Relative quantities of DNA in individual nuclei of stem and leaf epidermal cells of Arabidopsis were measured microspectrofluorometrically using epidermal peels. The relative ploidy level in each nucleus was assessed by comparison to root tip mitotic nuclei. A clear pattern of regular endopolyploidy is evident in epidermal cells. Guard cell nuclei contain levels of DNA comparable to dividing root cells, the 2C level (i.e., one unreplicated copy of the nuclear DNA). Leaf trichome nuclei had elevated ploidy levels of 4C, 8C, 16C, 32C, and 64C, and their cytology suggested that the polyploidy represents a form of polyteny. The nuclei of epidermal pavement cells were 2C, 4C, and 8C in stem epidermis, and 2C, 4C, 8C, and 16C in leaf epidermis. Morphometry of epidermal pavement cells revealed a direct proportionality between nuclear DNA level and cell size. A consideration of the development process suggests that the cells of highest ploidy level are developmentally oldest; consequently, the developmental pattern of epidermal tissues can be read from the ploidy pattern of the cells. This observation is relevant to theories of stomate spacing and offers opportunities for genetic analysis of the endopolyploidy/polyteny phenomenon.