Rice Importin β1 Gene Affects Pollen Tube Elongation
Rice Importin β1 Gene Affects Pollen Tube Elongation
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DOI：
10.1007/s10059-011-2321-7
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发表时间：
2011-06-01
影响因子：
3.8
通讯作者：
An, Gynheung
中科院分区：
文献类型：
--
作者：
Han, Min-Jung;Jung, Ki-Hong;An, Gynheung
Importin beta 1 与核转运因子相互作用并介导核蛋白的输入。我们从被无启动子 β-葡萄糖醛酸酶 (GUS) 基因捕获的 T-DNA 插入群体中分离出一个花粉表达基因，即水稻 Importin beta 1 (OsImp beta 1)。从早期到成熟的发育阶段，GUS 报告基因在花药和子房中表达。在所有花器官中也观察到其表达。然而，随着小穗的发育，这些模式发生了变化。 T-DNA 被插入 OsImp beta 1 基因翻译起始位点下游 339 bp 处。我们通过搜索侧翼序列标签数据库获得了另一个T-DNA插入等位基因。在这两个品系中，野生型和携带 T-DNA 的后代以接近 1:1 的比例分离。后一种基因型是杂合的（OsImp beta 1/osimp beta 1）。野生型和杂合植物之间的相互杂交证明突变等位基因不能通过雄配子体传播。对杂合花药的仔细检查表明突变花粉正常成熟。然而，体外试验表明，突变颗粒的管伸长受到阻碍。这些结果表明 OsImp beta 1 是花粉管伸长所特别需要的。
Importin beta 1 interacts with nuclear transport factors and mediates the import of nuclear proteins. We isolated a pollen-expressed gene, rice Importin beta 1 (OsImp beta 1), from a T-DNA insertional population that was trapped by a promoterless beta-glucuronidase (GUS) gene. The GUS reporter was expressed in the anthers and ovaries from early through mature developmental stages. Its expression was also observed in all floral organs. However, these patterns changed as the spikelet developed. T-DNA was inserted into the OsImp beta 1 gene at 339 bp downstream from the translation initiation site. We obtained another T-DNA insertional allele by searching the flanking sequence tag database. In both lines, the wild-type and T-DNA-carrying progeny segregated at a ratio close to 1:1. The latter genotype was heterozygous (OsImp beta 1/osimp beta 1). Reciprocal crosses between WT and heterozygous plants demonstrated that the mutant alleles could not be transmitted through the male gametophyte. Close examination of the heterozygous anthers revealed that the mutant pollen matured normally. However, in vitro assays showed that tube elongation was hampered in the mutant grains. These results indicate that OsImp beta 1 is specifically required for pollen tube elongation.