Redlinger T E, McDaniel R G
Department of Plant Sciences, University of Arizona, Tucson, Arizona 85721.
Plant Physiol. 1978 Jun;61(6):1006-9. doi: 10.1104/pp.61.6.1006.
Red light exposures given to dark-grown wheat seedlings (Triticum aestivum L.) prior to etioplast isolation reduced the ability of these organelles to consume O(2). The same preharvest red light exposures also decreased protochlorophyll(ide) content of etioplasts. In addition, regeneration of both O(2) uptake rates as well as protochlorophyll(ide) levels followed a parallel time course. These similarities suggested that photoconversion of protochlorophyll(ide)-650 to chlorophyll(ide) may mediate some process with O(2) as the electron acceptor. This process appears to involve photooxidation of nonphotoconvertible protochlorophyll(ide) as well as of newly formed chlorophyll(ide). This hypothesis is further supported by the observations that: (a) the in vitro light induced O(2) uptake phenomenon was observed in solubilized protochlorophyll(ide) holochrome preparations; and (b) photoinduced O(2) uptake was reduced to zero rate by light exposure time equivalent to that required for chlorophyll(ide) and nonphotoconvertible protochlorophyll(ide) destruction.
在分离黄化质体之前，对黑暗中生长的小麦幼苗（普通小麦）进行红光照射，会降低这些细胞器消耗氧气的能力。同样的收获前红光照射也会降低黄化质体中原叶绿素（酸）的含量。此外，氧气吸收速率和原叶绿素（酸）水平的恢复遵循平行的时间进程。这些相似性表明，原叶绿素（酸）-650向叶绿素（酸）的光转化可能介导了以氧气作为电子受体的某些过程。这个过程似乎涉及不可光转化的原叶绿素（酸）以及新形成的叶绿素（酸）的光氧化。以下观察结果进一步支持了这一假设：（a）在溶解的原叶绿素（酸）全色素制剂中观察到了体外光诱导的氧气吸收现象；（b）光诱导的氧气吸收通过与叶绿素（酸）和不可光转化的原叶绿素（酸）破坏所需时间相当的光照时间而降低至零速率。
