Department of Botany, Queens's University of Belfast, N. Ireland.
Planta. 1972 Mar;107(1):1-32. doi: 10.1007/BF00398011.
Cells of Chlorella fusca var. vacuolata (Cambridge 211/8p) resisted efforts aimed at producing naked protoplasts by enzymatic degradation of the cell wall, and a study of the development and composition of the wall was therefore undertaken. 1. After cytokinesis has produced naked autospores within the mother cell wall, cell wall formation commences outside the autospore plasma membrane with the appearance of small trilaminar plaques. These enlarge while inter-autospore granular material diminishes in quantity, and they eventually fuse to produce a complete trilaminar sheath around each autospore. 2. A microfibrillar, cellulase digestible, layer is deposited between the trilaminar component and the plasma membrane. Meanwhile the corresponding microfibrillar component of the mother cell wall is digested leaving only its resistant trilaminar component. 3. The trilaminar component includes a substance considered to be the polymerized carotenoid, sporopollenin, on the basis of its resistance to extreme extraction procedures including acetolysis, and its infra red absorption spectrum. 4. Two phases of sporopollenin biosynthesis were detected by means of pulse and pulse-chase treatments with (14)C-acetate at intervals during the cell cycle in synchronous cultures. One coincides with the formation of the sporopollenin-containing trilaminar wall component, and the other is 6-8 hours earlier while the cells are in karyokinesis. The former yields labelled sporopollenin directly and the latter probably represents formation of a precursor. 5. Of five other strains of Chlorella tested, only one possesses sporopollenin, and so does one Scenedesmus and two out of three strains of Prototheca. 6. Examination of the wall structure of the above algae suggest a relationship between the presence of sporopollenin and the development of an outer, trilaminar wall component. 7. A survey of the literature gives support to this hypothesis and further suggests that the ability to synthesise sporopollenin is related to the ability to produce secondary carotenoids. 8. The significance of the findings is discussed.
绿球藻变种空泡（剑桥 211/8p）的细胞抵抗了旨在通过酶解细胞壁来产生裸露原生质体的努力，因此进行了细胞壁的发育和组成研究。1. 在细胞分裂后，在母细胞壁内产生裸露的自孢子，细胞壁的形成始于自孢子质膜之外，出现小的三层膜斑。这些膜斑增大，而自孢子之间的颗粒物质减少，最终在每个自孢子周围融合形成完整的三层膜鞘。2. 在三层膜成分和质膜之间沉积了一层微纤维状、纤维素酶可消化的层。同时，母细胞壁的相应微纤维成分被消化，只留下其抗性三层膜成分。3. 三层膜成分包括一种被认为是聚合类胡萝卜素的物质，即孢粉素，基于其对极端提取程序的抗性，包括乙酰解，以及其红外吸收光谱。4. 通过在同步培养物的细胞周期中用（14）C-乙酸进行脉冲和脉冲追踪处理，检测到孢粉素生物合成的两个阶段。一个阶段与含有孢粉素的三层膜壁成分的形成相吻合，另一个阶段早 6-8 小时，此时细胞处于核分裂期。前者直接产生标记的孢粉素，后者可能代表前体的形成。5. 在测试的 5 种其他绿藻中，只有一种具有孢粉素，一种栅藻和三种 Prototheca 中的两种也具有孢粉素。6. 对上述藻类细胞壁结构的检查表明，孢粉素的存在与外层三层膜壁成分的发育之间存在关系。7. 对文献的调查支持了这一假设，并进一步表明合成孢粉素的能力与合成次生类胡萝卜素的能力有关。8. 讨论了这些发现的意义。
