PHOTON YIELD OF O-2 EVOLUTION AND CHLOROPHYLL FLUORESCENCE CHARACTERISTICS AT 77-K AMONG VASCULAR PLANTS OF DIVERSE ORIGINS
PHOTON YIELD OF O-2 EVOLUTION AND CHLOROPHYLL FLUORESCENCE CHARACTERISTICS AT 77-K AMONG VASCULAR PLANTS OF DIVERSE ORIGINS
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DOI：
10.1007/bf00402983
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发表时间：
1987-04-01
期刊：
影响因子：
4.3
通讯作者：
DEMMIG, B
中科院分区：
文献类型：
--
作者：
BJORKMAN, O;DEMMIG, B
测定了44种维管植物在饱和CO2条件下的放氧光子产率，这些植物代表了广泛多样的分类群、生境、生命形式和生长条件。在具有相同光合CO2固定途径的植物中，基于吸收光的光子产额值（φ a）是显著恒定的，只要植物没有受到环境胁迫。平均φ a值±。37种C_3植物的SE为0.106 ± 0.001。0.001 O2. cntdot.光子-1这五种C4物种表现出比C3物种更低的光子产额和更大的变化（φ a = 0.0692 ± 0.0001）。0.004）。两种景天科酸代谢物种的φ a值与C3物种的φ a值相似。叶片叶绿素含量在正常健康叶片中发现的范围内对φ a几乎没有影响。叶绿素荧光特性在77 K的测定用于相同的叶片的光子产额测量。在692 nm和734 nm处的荧光发射中发现了相当大的变化：1）在不同物种之间; 2）在相同叶片的上表面和下表面之间; 3）在相同物种的阳叶和阴叶之间。相比之下，在692 nm处的可变荧光发射与最大荧光发射的比率（FV/FM，692）保持显著恒定（C3物质的平均值为0.832 ± 0.001）。0.004）。遮荫叶的高光处理导致φ a和FV/FM，692比率的降低。减少的程度随着暴露于强光的时间而增加。当将φ a相对于FV/FM，692作图时，获得线性关系。结果表明，测定O2释放的光子产率和FV/FM，692比值可以作为整个光合能量转换系统的光抑制和光系统II的光化学的良好的定量措施，分别。这在现场工作中特别有价值，因为现场工作通常不可能获得适当的控制。
Photon yields of oxygen evolution at saturating CO2 were determined for 44 species of vascular plants, representing widely diverse taxa, habitats, life forms and growth conditions. The photon-yield values on the basis of absorbed light (.phi.a) were remarkably constant among plants possessing the same pathway of photosynthetic CO2 fixation, provided the plants had not been subjected to environmental stress. The mean .phi.a value .+-. SE for 37 C3 species was 0.106 .+-. 0.001 O2 .cntdot. photon-1. The five C4 species exhibited lower photon yields and greater variation than the C3 species (.phi.a = 0.0692 .+-. 0.004). The .phi.a values for the two Crassulacean-acid-metabolism species were similar to those of C3 species. Leaf chlorophyll content had little influence on .phi.a over the range found in normal, healthy leaves. Chlorophyll fluorescence characteristics at 77 K were determined for the same leaves as used for the photon-yield measurements. Considerable variation in fluorescence emission both at 692 nm and at 734 nm, was found 1) among the different species; 2) between the upper and lower surfaces of the same leaves; and 3) between sun and shade leaves of the same species. By contrast, the ratio of variable to maximum fluorescence emission at 692 nm (FV/FM, 692) remained remarkably constant (The mean value for the C3 species was 0.832 .+-. 0.004). High-light treatments of shade leaves resulted in a reduction in both .phi.a and the FV/FM, 692 ratio. The extent of the reductions increased with time of exposure to bright light. A linear relationship was obtained when .phi.a was plotted against FV/FM, 692. The results show that determinations of the photon yield of O2 evolution and the FV/FM, 692 ratio can serve as excellent quantitative measures of photoinhibition of overall photosynthetic energy-conversion system and of photochemistry of photosystem II, respectively. This is especially valuable in field work where it is often impossible to obtain appropriate controls.