The cell wall of kiwifruit pollen tubes is a target for chromium toxicity: alterations to morphology, callose pattern and arabinogalactan protein distribution.
The cell wall of kiwifruit pollen tubes is a target for chromium toxicity: alterations to morphology, callose pattern and arabinogalactan protein distribution.
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DOI：
10.1111/j.1438-8677.2008.00129.x
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发表时间：
2009-03
期刊：
影响因子：
3.9
通讯作者：
A. Speranza;A. Taddei;G. Gambellini;E. Ovidi;V. Scoccianti
中科院分区：
文献类型：
--
作者：
A. Speranza;A. Taddei;G. Gambellini;E. Ovidi;V. Scoccianti
此前已发现三价铬在体外能有效抑制猕猴桃花粉管的出现和伸长。在本研究中，对发芽过程中管壁产量增加的光度测量表明，25 和 50 mum CrCl(3) 处理导致壁中多糖水平比对照显着降低。此外，经过铬处理的猕猴桃花粉管具有不规则和锯齿状的细胞壁。胼胝质是主要的管壁多糖，以异常的点状图案沉积。阿拉伯半乳聚糖蛋白 (AGP) 是维持猕猴桃花粉管正确生长和形状的重要组成部分，经 CrCl(3) 处理后，与对照管壁相比，其分布发生了强烈改变。使用四种单克隆抗体（JIM8、JIM13、JIM14 和 MAC207）进行的透射电子显微镜-免疫金分析显示，经处理的管壁内存在不连续的 AGP 分布。花粉管壁分子和形态结构的这种明显可辨别的变化可能不利于雄性配子体在体内发挥其在受精过程中的重要作用。
Trivalent chromium has previously been found to effectively inhibit kiwifruit pollen tube emergence and elongation in vitro. In the present study, a photometric measure of increases in tube wall production during germination showed that 25 and 50 mum CrCl(3) treatment induced a substantial reduction in levels of polysaccharides in walls over those in controls. Moreover, chromium-treated kiwifruit pollen tubes had irregular and indented cell walls. Callose, the major tube wall polysaccharide, was deposited in an anomalous punctuate pattern. Arabinogalactan proteins (AGPs), which are integral in maintaining correct tube growth and shape in kiwifruit pollen, were found to be strongly altered in their distribution after CrCl(3) treatment compared to control tube walls. Transmission electron microscopy-immunogold analysis using four monoclonal antibodies (JIM8, JIM13, JIM14 and MAC207) revealed discontinuous AGP distribution within the treated tube walls. Such clearly discernable alterations in the molecular and morphological architecture of pollen tube walls may be detrimental in vivo for the male gametophyte to accomplish its vital role in the fertilisation process.