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作 者 ：钟泽璞 施定基

期 刊 ：植物学通报 2000年 17卷 03期 页码：204-210

关键词：蓝藻；藻殖段分化；调节机制；

摘 要 ：本文介绍了丝状体蓝藻(亦称蓝细菌) 的藻殖段的分化及其调节机制。藻殖段与正常藻丝体的区别在于细胞形状、细胞内存有气囊和可移动的短而直的藻丝链等。本文对许多环境因子包括光和营养因素等促进或抑制藻殖段的分化进行了讨论；还介绍了念珠藻(Nostoc) ，单歧藻(Tolypothrix) 和眉藻(Calothrix)所具有复杂的细胞发育过程，即具气囊又可移动的藻殖段分化，异形胞分化以及营养细胞的补偿性色适应。这三种细胞类型的适应形成取决于两种不同的光受体系统。藻殖段和异形胞两者的分化可能取决于光合电子传递链；而营养细胞的补偿性色适应则受光敏色素的调节。此外，谷酰胺合成酶合成和活性调节的PII蛋白，在协同藻殖段分化、异形胞分化及营养细胞的补偿色适应中起重要作用。由于蓝藻藻殖段分化及其调节机制是一个新的研究领域，关于它的知识尚不完整，亟待人们加强研究。

Abstract:The article reviews the differentiation of hormogonia of several filamentous heterocystous cyanobacteria and their regulatory mechani sms. The hormogonia are distinguishable from vegetative trichomes by the cell shape, the presence of gas vesicles and cell motility. Numerous environmental factors, including light and nutrients, can stimulate or inhibit hormogonium differentiation. Some strains belonging to genera Nostoc, Tolypothrix and Calothrix display a complex developmental cell cycle that includes both the differentiation of gasvacuolated hormogonia, heterocyst differentiation and complementary chromatic adaptation. These three types of adaption depend on two different photoreceptor system s. The control of both hormogonium and heterocyst differentiation depends on the photosynthetic electron transport chain, but complimentary chromatic adaptation appears to be controlled by a photoreversible pigment. The cyanobacterial PII protein that is involved in the control of both synthesis and activity of glutamine synthetase plays a role in the coordination of hormogonium and heterocyst differentiation and complementary chromatic adaptation. The differentaition of hormogonia from cyanobacteria and their regulation mechanisms are subjects that need more thorough investigation because of the incompleteness of the knowledge of hormogonia.

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