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作 者 ：李敦海 宋立荣 刘永定

期 刊 ：植物学通报 2002年 19卷 03期 页码：328-335

关键词：念珠藻；葛仙米；藻殖段；信号转导；分化；

摘 要 ：钙调素拮抗剂W-7和FPZ均可抑制葛仙米藻殖段的分化。利用FPZ作为荧光染色剂发现，经过钙调素拮抗剂处理的藻体有较低的钙调素分布。在达到一定浓度后，金属离子螯合剂EGTA也抑制藻殖段分化。金霉素（CTC）荧光显示，经EGTA处理的藻细胞其膜钙分布大大减少。但实验表明，藻殖段得以正常分化却是多种金属离子共同参与的结果。一氧化氮（NO）可以大大降低葛仙米藻殖段的分化率，一氧化氮合成酶（NOS）的抑制剂NNA也可以抑制藻殖段的分化。外源地加入氧自由基抑制了藻殖段的分化，但是氧自由基的清除物过氧化氢酶（CA）也使藻殖段分化完全受抑制。以上结果初步表明，葛仙米藻殖段分化是个复杂的、信号转导参与的过程。

Abstract:Hormogonia differentiation in Nostoc sphaeroides can be inhibited by calmodulin antagonists W-7 and Fluphenazine (FPZ). FPZ fluorescence showed that the cellular calmodulin distributions were less than that of control after treatment of calmodulin antagonists. When reached to a certain concentration, the chelator EGTA could also block the differentiation of hormogonia. As shown by CTC fluorescenc e, the membrane-bounded Ca2+of algal cells was significantly decreased after treatment of EGTA. The results suggested that the complete differentiation of hormogonia was a process coordinated by several metallic ions. Nitric oxide (NO) could decrease the rate of hormogonia differentiation to a large extent, but at the same time, NAA, an inhibitor of nitric oxide synthetase (NOS), also could completely inhibit the differentiation. The differentiation process could be inhibited by exogenously added reactive oxygen intermediates (ROIs), while catalase (CA), the scavenger of ROIs, stopped the differentiation process too. The above results implied that the differentiation process of hormogonia in Nostoc sphaeroides was mediated by a complicated signal transduction system.

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