Quigg Antonietta, Beardall John, Wydrzynski Tom
School of Biological Sciences, Monash University, Melbourne, Vic. 3800, Australia. Research School of Biological Sciences, The Australian National University, Canberra, ACT 2000, Australia. Present address: Environmental Biophyhics and Molecular Energy Program, Institute of Marine and Coastal Sciences, Rutgers, The State University of New Jersey, NJ 08901, USA. Corresponding author; email:
School of Biological Sciences, Monash University, Melbourne, Vic. 3800, Australia.
Funct Plant Biol. 2003 Mar;30(3):301-308. doi: 10.1071/FP02140.
Net energy accumulation by marine microalgae at very low photon fluxes involves modulation of several attributes related to both the growth and photosynthetic physiology of these organisms. Here we studied flash-induced oscillatory patterns in oxygen evolution by previously dark-adapted cells of the green alga Dunaliella tertiolecta (Butcher) and the diatom Phaeodactylum tricornutum (Bohlin). The activity of the oxygen-evolving complex was found to be species-specific and influenced by photoacclimation. Results from measurements of oxygen flash yield obtained for these organisms grown under light-saturating conditions are directly comparable to those previously reported in the literature for other microalgae and higher plants. However, similar measurements on cells grown in low-light and/or light-starved conditions indicate an increased level of backward transitions (double misses) leading to the formation of super-reduced states (i.e. S and S). Thus, in this communication, we present the first evidence that super-reduced states can be generated in vivo and speculate, on how they may be physiologically important.
海洋微藻在极低光子通量下的净能量积累涉及对这些生物体生长和光合生理相关的几个属性的调节。在这里，我们研究了绿藻杜氏盐藻（Butcher）和硅藻三角褐指藻（Bohlin）先前经暗适应的细胞在闪光诱导下的氧气释放振荡模式。发现放氧复合体的活性具有物种特异性，并受光适应影响。对这些在光饱和条件下生长的生物体所获得的氧气闪光产率测量结果，可直接与文献中先前报道的其他微藻和高等植物的结果相比较。然而，对在低光和/或缺光条件下生长的细胞进行的类似测量表明，向后跃迁（双失活）水平增加，导致形成超还原状态（即S和S）。因此，在本通讯中，我们首次提供了超还原状态可在体内产生的证据，并推测它们在生理上可能具有的重要性。
