Ultrastructural and chemical changes in the cell wall of Haematococcus pluvialis (Volvocales, Chlorophyta) during aplanospore formation
Ultrastructural and chemical changes in the cell wall of Haematococcus pluvialis (Volvocales, Chlorophyta) during aplanospore formation
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DOI：
10.1017/s0967026202003669
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发表时间：
2002-05-01
影响因子：
2.4
通讯作者：
Braune, W
中科院分区：
文献类型：
--
作者：
Hagen, C;Siegmund, S;Braune, W
研究了单细胞藻类绿藻雨生红球藻在鞭毛虫转化为无孢子过程中细胞壁超微结构和化学的变化。活动的双鞭毛状态表现出独特的凝胶状细胞外基质。其超微结构类似于典型的volvocalean多层结构，具有中间三部分晶层。向非运动细胞状态的转变的特征是在细胞外基质内形成新层，即初生壁。在此过程中，除了三方结晶层的外层分解外，最初的细胞外基质保持完整。无球孢子的进一步形态发生导致大量多层细胞壁的形成。初生壁内部形成三层鞘，最里面最厚的部分是不定形的次生壁。主要由甘露聚糖组成。通过荧光染料报春碱染色以及丙酮分解获得的结果表明，无球孢子细胞壁的三层鞘内存在孢粉质样物质（藻聚糖），随着无球孢子老化，初生壁和细胞外基质的外部残余物解体。并且在静息细胞状态下完全不存在。
Changes in the ultrastructure and chemistry of the cell wall of the unicellular volvocalean green alga Haematococcus pluvialis were investigated during the transformation of flagellates into aplanospores. The motile biflagellated state exhibited a distinct gelatinous extracellular matrix. Its ultrastructure resembled the typical volvocalean multilayered architecture with a median tripartite crystalline layer. The transformation into the non-motile cell state was characterized by formation of a new layer, a primary wall, within the extracellular matrix. During this process, the initial extracellular matrix remained intact except for the outer layers of the tripartite crystalline layer, which decomposed. Further morphogenesis of the aplanospore resulted in the formation of a voluminous multilayered cell wall. A trilarninar sheath was formed inside the primary wall and the innermost and thickest part was an amorphous secondary wall. consisting mostly of a mannan. Results obtained by staining with the fluorescent dye primuline as well as by acetolysis suggest the occurrence of sporopollenin-like material (algaenan) within the trilaminar sheath of the aplanospore cell wall, The primary wall and the outer remnants of the extracellular matrix disintegrated as the aplanospores aged. and were completely absent in the resting cell state.