Sokolove P M, Marsho T V
Biochim Biophys Acta. 1977 Jan 6;459(1):27-35. doi: 10.1016/0005-2728(77)90005-6.
The divalent-cation-specific ionophore A23187 is used to define two components of the slow fluorescence quenching of type a spinach chloroplasts: ionophore-reversible and ionophore-resistant quenching. Ionophore-reversible quenching predominates at relatively low light intensities and approaches saturation as light levels are increased. It is sensitive to uncouplers and to 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) and is dark reversible. At high light intensities the bulk (greater than 80%) of slow fluorescence quenching is ionophore-resistant. Ionophore-resistant quenching is stimulated by carbonyl cyanide m-chlorophenyl hydrazone (CCCP) at pH 7.6 and by both CCCP and methylamine at pH 9.0. It is insensitive to DCMU and is not reversed in subsequent darkness. Taken together, the two components account for all quenching observed in Type A chloroplasts. Ionophore-reversible quenching is identified with the Mg2+-mediated fluorescence quenching described by Krause (Biochim. Biophys. Acta (1974) 333, 301-313) and by Barber and Telfer (in Membrane Transport in Plants (Dainty, J., AND Zimmermann, U., eds.), pp. 281-288, Springer-Verlag, Berlin, 1974). Ionophore-resistant quenching, a first-order process requiring high light, resembles the quenching reported by Jennings et al. (Biochim. Biophys. Acta (1976) 423, 264-274). The resolution of the fluorescence quenching phenomenon into two distinct components reconciles the apparently contradictory observations of these earlier investigations.
二价阳离子特异性离子载体A23187用于确定a型菠菜叶绿体缓慢荧光猝灭的两个组分：离子载体可逆猝灭和离子载体抗性猝灭。离子载体可逆猝灭在相对较低的光照强度下占主导，随着光照水平的增加接近饱和。它对解偶联剂和3-(3,4-二氯苯基)-1,1-二甲基脲（DCMU）敏感，并且在黑暗中是可逆的。在高光强度下，大部分（大于80%）的缓慢荧光猝灭是离子载体抗性的。在pH 7.6时，羰基氰m-氯苯腙（CCCP）以及在pH 9.0时CCCP和甲胺均可刺激离子载体抗性猝灭。它对DCMU不敏感，并且在随后的黑暗中不会逆转。总之，这两个组分解释了在A型叶绿体中观察到的所有猝灭现象。离子载体可逆猝灭与Krause（《生物化学与生物物理学报》（1974年）333卷，301 - 313页）以及Barber和Telfer（载于《植物中的膜运输》（Dainty, J.和Zimmermann, U.编），第281 - 288页，施普林格出版社，柏林，1974年）所描述的Mg2+介导的荧光猝灭一致。离子载体抗性猝灭是一个需要高光的一级过程，类似于Jennings等人（《生物化学与生物物理学报》（1976年）423卷，264 - 274页）报道的猝灭。将荧光猝灭现象解析为两个不同的组分，调和了这些早期研究中明显相互矛盾的观察结果。
