Scherer Siegfried, Ernst Anneliese, Chen Ting-Wei, Böger Peter
Lehrstuhl für Physiologie und Biochemie der Pflanzen, Universität Konstanz, D-7750, Konstanz, Federal Republic of Germany.
Soils and Fertilizer Institute, Chinese Academy of Agricultural Sciences, 30 Baishiqiao Lu, 100081, Beijing, Peoples Republic of China.
Oecologia. 1984 Jun;62(3):418-423. doi: 10.1007/BF00384277.
The response of the terrestrial blue-green algae Nostoc flagelliforme, Nostoc commune, and Nostoc spec. to water uptake has been investigated after a drought period of approximately 2 years. Rapid half-times of rewetting (0.6, 3.3, and 15.5 min, respectively) are found. The surfaceto-mass ratio of the three species is inversely correlated to the speed of water uptake and loss. The ecological relevance of these different time courses is discussed.Respiration starts immediately after a 30-min rewetting period, whereas photosynthetic oxygen evolution reaches its maximum activity after 6 and 8 h with N. commune and N. flagelliforme, respectively. In the dark, recovery of oxygen uptake by N. commune is somewhat impaired, while slightly stimulated with N. flagelliforme. With both species, recovery of photosynthesis is inhibited by darkness.Using colonies kept dry for two years, nitrogenase activity of N. commune attains its maximum 120 to 150 h after rewetting, while only 50 h were needed with algal mats kept dry for two days.Thus, after a 2-year drought period, the physiological sequence of reactivation is respiration-photosynthesis-nitrogen fixation. Respiration and photosynthesis precede growth and are exhibited by existing vegetative cells, whereas recovery of nitrogen fixation is dependent on newly differentiated heterocysts.
在经历了约两年的干旱期后，对陆生蓝绿藻发菜、地木耳和念珠藻属进行了水分吸收响应的研究。发现它们的再湿润半衰期很快（分别为0.6、3.3和15.5分钟）。这三个物种的表面积与质量比与水分吸收和损失的速度呈负相关。讨论了这些不同时间进程的生态相关性。在30分钟的再湿润期后呼吸立即开始，而地木耳和发菜的光合放氧分别在6小时和8小时后达到最大活性。在黑暗中，地木耳的氧吸收恢复有所受损，而发菜则略有刺激。对于这两个物种，光合作用的恢复都受到黑暗的抑制。使用干燥保存两年的藻殖段，地木耳的固氮酶活性在再湿润后120至150小时达到最大值，而对于干燥保存两天的藻席则只需50小时。因此，在经历两年干旱期后，重新激活的生理顺序是呼吸作用-光合作用-固氮作用。呼吸作用和光合作用先于生长，由现有的营养细胞表现出来，而固氮作用的恢复则依赖于新分化的异形胞。
