Radyuk Mechislav S, Homan Natalia M
National Academy of Sciences of Belarus, Institute of Photobiology, Akademicheskaya st. 27, Minsk, 220072, Belarus,
Photosynth Res. 2002;72(1):117-22. doi: 10.1023/A:1016093127057.
Biogenesis of the photosynthetic apparatus in greening etiolated leaves of barley (Hordeum vulgare L) was investigated by an approach permitting investigation of this process under conditions that minimize differences in plastid development. Distributions of barley leaves greening for 24 h as to chlorophyll content and of chloroplast grana as to number of thylakoids were shown to be of a multimodal character. The shape of time-course curves of chlorophyll accumulation in local sites of greening etiolated leaves was of a stepped or (at the end of greening) undulated character. The stepwise accumulation of chlorophyll was accompanied by wave-like changes in chlorophyll b/a ratio, intensity of low-temperature chlorophyll fluorescence and photosynthetic activity with minima at the time points of transition to accelerated chlorophyll accumulation. It is assumed that (1) development of the photosynthetic apparatus in local sites of greening etiolated leaves occurs stepwise, from one steady level to another, but not as gradually as is generally accepted, and (2) every separate step in development of the photosynthetic apparatus seems to begin with formation of photosystem cores and to end with the synthesis of light-harvesting complexes.
通过一种能在使质体发育差异最小化的条件下研究该过程的方法，对大麦（Hordeum vulgare L）黄化叶片绿化过程中光合器官的生物发生进行了研究。结果表明，绿化24小时的大麦叶片叶绿素含量分布以及叶绿体基粒类囊体数量分布具有多峰特征。黄化叶片局部绿化部位叶绿素积累的时间进程曲线呈阶梯状或（绿化末期）波动状。叶绿素的逐步积累伴随着叶绿素b/a比值、低温叶绿素荧光强度和光合活性的波浪式变化，在叶绿素加速积累的时间点出现最小值。据推测：（1）黄化叶片局部绿化部位光合器官的发育是逐步进行的，从一个稳定水平过渡到另一个稳定水平，并非如普遍认为的那样是逐渐进行的；（2）光合器官发育的每一个独立步骤似乎都始于光系统核心的形成，终于捕光复合体的合成。
