In vivo pollen tube cell of Arabidopsis thaliana I.: Tube cell cytoplasm and wall
In vivo pollen tube cell of Arabidopsis thaliana I.: Tube cell cytoplasm and wall
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DOI：
10.1007/bf02524261
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发表时间：
2000-01-01
期刊：
影响因子：
2.9
通讯作者：
Lord, EM
中科院分区：
文献类型：
--
作者：
Lennon, KA;Lord, EM
花粉管是研究植物极化尖端生长、细胞运动和细胞间通讯的良好系统。我们报道了第一次在透射电镜水平上对冷冻的、在体内生长的花粉管的描述。拟南芥生长在花柱中的管状细胞可分为四个区，与报道的茄科成员的花粉管细胞相似。与其他物种报道的数据有一些明显的差异，包括花粉管和周围传递组织中明显缺乏阿拉伯半乳聚糖蛋白的形态、花尖壁的组成。拟南拟南的透明区充满了囊泡，这些囊泡不像其他物种那样形成倒锥，它们在尖端区域与质膜融合成簇。免疫细胞化学分析显示，花粉管顶端有一个初生果胶壁，仅由高度酯化的同半乳糖醛酸组成。这个壁基本上变得越来越厚，在透明区后面由高度酯化和低酯化的均半乳糖醛酸组成。透明带后面出现次生胼胝体壁，并逐渐变厚。使用各种探针，我们无法在花粉管细胞或花柱传递组织中鉴定任何阿拉伯半乳聚糖蛋白。与我们之前报道的卵巢隔传递组织的细胞外基质不同，花柱基质富含高和低酯化的同半乳糖醛酸盐。
Pollen tubes are an excellent system for the study of polarized tip growth, cell movement, and cell-to-cell communication in plants. We report the first description at the transmission electron microscope level of cryofixed, in vivo grown pollen tubes. The tube cell of Arabidopsis thaliana growing in the style can be divided into four zones, similar to those reported for pollen tube cells of members of the family Solanaceae. Some distinct differences from data reported for other species include the morphology of the clear zone at the tip, the composition of the tip wall, and the apparent lack of arabinogalactan proteins in the pollen tube and surrounding transmitting tissue. The clear zone of A. thaliana is packed with vesicles which do not form the inverted cone found in other species and that fuse in clusters with the plasmalemma in the tip region. Immunocytochemical analyses revealed that the pollen tube has a primary, pectic wall composed solely of highly esterified homogalacturonans at the tip. This wall becomes increasingly thicker basipetally and is composed of both highly esterified and lowly esterified homogalacturonans behind the clear zone. A secondary callosic wall appears behind the clear zone and becomes thicker basipetally. Using a variety of probes, we have been unable to identify any arabinogalactan proteins in the pollen tube cell or in the transmitting tissue of the style. Unlike our earlier reports of the extracellular matrices of the septum transmitting tissue of the ovary, the stylar matrices were found to be rich in both highly and lowly esterified homogalacturonans.