Osafune T, Schiff J A, Hase E
Institute for Photobiology of Cells and Organelles, Brandeis University, Waltham, Massachusetts 02254.
Cell Struct Funct. 1987 Oct;12(5):453-61. doi: 10.1247/csf.12.453.
Cells of Euglena gracilis Klebs var. bacillaris Cori mutant W3BUL grown in darkness on Hutner's pH 3.5 medium without agitation accumulate wax ester. These cells have undeveloped proplastid remnants characteristic of this mutant. If these cells are transferred to an inorganic medium and bubbled with 2-3% CO2 in air, the wax disappears and the proplastid expands and develops in darkness to form prolamellar bodies and membrane vessicles within 96 h. No further development takes place in darkness, but if these cultures are illuminated at 96 h formation of prothylakoids is observed. Thus the wax ester accumulated during growth can be used subsequently to support proplastid development up to the prolamellar body stage, but the formation of prothylakoids is strictly light-dependent. Development in this system takes place at a slower rate than in cells grown with shaking and lacking wax which are transferred to resting medium. As previously shown, all of proplastid development requires light under these conditions. It is suggested that the oxygen-requiring utilization of wax in darkness can provide energy and metabolites for a part of proplastid development but the later steps in these cells, or the entire development in cells lacking wax is supported by paramylum degradation which is strictly light-dependent. However, a specific light reaction required for prothylakoid organization is not ruled out.
纤细裸藻克莱布斯变种杆状变种科里突变体W3BUL的细胞，在黑暗中于pH 3.5的赫特纳培养基上静置培养时会积累蜡酯。这些细胞具有该突变体特有的未发育的原质体残余物。如果将这些细胞转移到无机培养基中，并在空气中用2 - 3%的二氧化碳鼓泡，蜡会消失，原质体在黑暗中膨胀并发育，在96小时内形成原片层体和膜泡。在黑暗中不会进一步发育，但如果在96小时时对这些培养物进行光照，会观察到类囊体原基的形成。因此，生长过程中积累的蜡酯随后可用于支持原质体发育至原片层体阶段，但类囊体原基的形成严格依赖光照。该系统中的发育速度比在摇晃培养且缺乏蜡的细胞转移到静止培养基中的发育速度要慢。如前所示，在这些条件下，所有原质体发育都需要光照。有人认为，黑暗中蜡的需氧利用可为原质体发育的一部分提供能量和代谢产物，但这些细胞后期的步骤，或缺乏蜡的细胞中的整个发育过程是由支链淀粉降解支持的，而支链淀粉降解严格依赖光照。然而，并不排除类囊体原基形成所需的特定光反应。
