HETEROCYST AND NITROGENASE DEVELOPMENT IN ANABAENA-CYLINDRICA
HETEROCYST AND NITROGENASE DEVELOPMENT IN ANABAENA-CYLINDRICA
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DOI：
10.1099/00221287-96-1-175
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发表时间：
1976-01-01
期刊：
影响因子：
--
通讯作者：
CARR, NG
中科院分区：
文献类型：
--
作者：
BRADLEY, S;CARR, NG
研究了去除固定氮后白茅连续培养菌丝的分化情况。观察到原异囊（4.5 h）和成熟异囊（14 h）按顺序快速发育；后者的发展与氮酶活性的开始同时发生。分别测量2.3 h（原胚）和5.0 h（异胚）的承诺时间。有证据表明，杂种囊的发育，而不是杂种囊固定氮功能的任何产物，是造成营养细胞丝中杂种囊模式的原因。在异囊发育的早期，整个花丝的藻蓝蛋白含量和CO2固定量都明显下降，表明花丝的所有细胞都参与了分化过程的初始阶段。异囊在光线下不产生氧气，但会呼吸。磷酸烯醇丙酮酸、ATP和二氯酚吲哚酚抗坏血酸刺激了离体异囊和完整纤维的氮酶活性。
The differentiation of filaments of a continuous culture of A. cylindrica after removal of fixed N was examined. Rapid development of proheterocysts (4.5 h) and mature heterocysts (14 h) in an ordered sequence was observed; the development of the latter was concomitant with the onset of nitrogenase activity. Commitment times of 2.3 h (proheterocyst) and 5.0 h (heterocyst) were measured. Evidence shows that heterocyst development, rather than any product of heterocyst function in N fixation, is responsible for the imposition of the pattern of heterocysts in a filament of vegetative cells. Both phycocyanin content and CO2 fixation declined markedly throughout the filament during the early stages of heterocyst development, indicating that all the cells of the filament are involved in the initial stages of the differentiation process. Heterocysts do not evolve O2 in the light, but do respire. Nitrogenase activity in isolated heterocysts and in intact filaments was stimulated by phosphoenolpyruvate, ATP and dichlorophenolindophenol-ascorbate.