Free IAA in stigmas and styles during pollen germination and pollen tube growth of Nicotiana tabacum
Free IAA in stigmas and styles during pollen germination and pollen tube growth of Nicotiana tabacum
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DOI：
10.1111/j.1399-3054.2008.01125.x
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发表时间：
2008-09-01
影响因子：
6.4
通讯作者：
Zhao, Jie
中科院分区：
文献类型：
--
作者：
Chen, Dan;Zhao, Jie
尽管许多研究强调了生长素在植物生长和发育中的重要性，但对其对花粉-雌蕊相互作用的影响的透彻理解在很大程度上尚不清楚。在这项研究中，我们通过使用生长素单克隆抗体进行组织和亚细胞免疫定位，通过 HPLC 和 ELISA 定量以及 DR5::GUS 转化植物中的 GUS 染色，研究了游离 IAA 在烟草花粉萌发和管生长过程中花粉 - 雌蕊相互作用中的作用。结果表明，未授粉花柱顶端部和基部的游离IAA含量高于中部，且在传递组织（TT）中含量更高。花粉萌发阶段IAA在柱头含量最高，主要分布在TT处。花粉管进入花柱后，花粉管即将进入的部分信号增强，而花粉管已穿透的部分信号迅速下降。亚细胞定位证实柱头和花柱的 TT 细胞中存在 IAA。因此，示意图总结了开花、授粉和花粉管生长期间游离IAA水平的变化模式。此外，我们提供的证据表明，低浓度的外源IAA可以在一定程度上促进体外花粉管的生长。这些结果表明IAA可能直接或间接参与花粉-雌蕊相互作用。此外，还对 IAA 免疫定位技术进行了一些改进。
Although many studies have emphasized the importance of auxin in plant growth and development, the thorough understanding of its effect on pollen-pistil interactions is largely unknown. In this study, we investigated the role of free IAA in pollen-pistil interactions during pollen germination and tube growth in Nicotiana tabacum L. through using histo and subcellular immunolocalization with auxin monoclonal antibodies, quantification by HPLC and ELISA together with GUS staining in DR5::GUS-transformed plants. The results showed that free IAA in unpollinated styles was higher in the apical part and basal part than in the middle part, and it was more abundant in the transmitting tissue (TT). At the stage of pollen germination, IAA reached its highest content in the stigma and was mainly distributed in TT. After the pollen tubes entered the styles, the signal increased in the part where pollen tubes would enter and then rapidly declined in the part where pollen tubes had penetrated. Subcellular localization confirmed the presence of IAA in TT cells of stigmas and styles. Accordingly, a schematic diagram summarizes the changing pattern of free IAA level during flowering, pollination and pollen tube growth. Furthermore, we presented evidence that low concentration of exogenous IAA could, to a certain extent, facilitate in vitro pollen tube growth. These results suggest that IAA may be directly or indirectly involved in the pollen-pistil interactions. Additionally, some improvements of the IAA immunolocalization technique were made.