文献类型： 外文期刊

作者： Jing, HC ¹ ; van Lammeren, AAM ² ; de Castro, RD ² ; Bino, RJ ² ; Hilhorst, HWM ² ; Groot, SPC ² ;

作者机构： 1.Ctr Plant Breeding & Reprod Res, Agr Res Dept, NL-6700 AA Wageningen, Netherlands

2.Ctr Plant Breeding & Reprod Res, Agr Res Dept, NL-6700 AA Wageningen, Netherlands; Wageningen Univ Agr, Lab Plant Cytol & Morphol, Wageningen, Netherlands; Wageningen Univ Agr, Lab Plant Physiol, Wageningen, Netherlands; Tianjin Acad Agr Sci, Tianjin, Peoples R China

关键词： bromodeoxyuridine incorporation;Cucumis sativus;DNA synthesis;germination;microtubular cytoskeleton;beta-tubulin accumulation

期刊名称：PROTOPLASMA （ 影响因子：3.356； 五年影响因子：3.298 ）

ISSN： 0033-183X

年卷期： 1999 年 208 卷 1-4 期

页码：

收录情况： SCI

摘要： Resumption of DNA synthetic activities and beta-tubulin accumulation was studied in embryo organs of germinating cucumber (Cucumis sativus L.) seeds. Flow-cytometric analysis indicated the existence of 2C, 4C, and 8C nuclei in the radicle of mature embryos, whereas in cotyledons most of the cells contained nuclei with 2C DNA content. Upon imbibition of water, nuclear DNA replication was initiated in the radicle within 15 h, subsequently spreading towards the cotyledons. Bromodeoxyuridine incorporation preceded detectable changes in the relative amounts of DNA, implying the occurrence of putative DNA repair. Organellar DNA synthesis occurred independently of the nuclear DNA synthetic cycle. Western blotting and immunohistochemical localization demonstrated that the constitutive level of beta-tubulin originated from preserved P-tubulin granules. During imbibition, disappearance of fluorescent tubulin granules, accumulation of beta-tubulin, and formation of microtubular cytoskeleton were found in the radicle, but not in the cotyledon areas. Mitosis only occurred after radicle protrusion at 21 h of imbibition. It is concluded that the differences in the initiation and progress of these cellular and molecular events are associated with the discrete behaviors of the radicle and the cotyledons upon imbibition. The formation of cortical microtubular cytoskeleton and the accumulation of tubulins are important features in preparation of radicle protrusion, whereas DNA synthesis may contribute to postgerminative growth.