A chloroplast gene is required for the light‐independent accumulation of chlorophyll in Chlamydomonas reinhardtii.
A chloroplast gene is required for the light‐independent accumulation of chlorophyll in Chlamydomonas reinhardtii.
复制标题
莱茵衣藻中叶绿素的不依赖于光的积累需要叶绿体基因。
作者：
Y. Choquet;M. Rahire;J. Girard‐Bascou;J. Erickson;J. Rochaix
一些低等植物和藻类中发生的不依赖于光的叶绿素合成途径仍然很大程度上未知。我们已经鉴定了莱茵衣藻的叶绿体突变体 H13，它无法在黑暗中合成叶绿素，并且也缺乏光系统 I。该突变体的叶绿体基因组有 2.8 kb 的缺失以及其他重排。通过使用确定的野生型叶绿体 DNA 片段对 H13 进行粒子枪介导的叶绿体转化，我们鉴定了一种新的叶绿体基因 chlN，它编码 545 个氨基酸的蛋白质，该蛋白质参与叶绿素的光独立积累，可能在原叶绿素内酯还原为叶绿素内酯的步骤中。 ChlN 基因也存在于地钱和松树的叶绿体基因组中，但在烟草和水稻的叶绿体基因组中不存在。
The light‐independent pathway of chlorophyll synthesis which occurs in some lower plants and algae is still largely unknown. We have characterized a chloroplast mutant, H13, of Chlamydomonas reinhardtii which is unable to synthesize chlorophyll in the dark and is also photosystem I deficient. The mutant has a 2.8 kb deletion as well as other rearrangements of its chloroplast genome. By performing particle gun mediated chloroplast transformation of H13 with defined wild‐type chloroplast DNA fragments, we have identified a new chloroplast gene, chlN, coding for a 545 amino acid protein which is involved in the light‐independent accumulation of chlorophyll, probably at the step of reduction of protochlorophyllide to chlorophyllide. The chlN gene is also found in the chloroplast genomes of liverwort and pine, but is absent from the chloroplast genomes of tobacco and rice.