Choquet Y, Rahire M, Girard-Bascou J, Erickson J, Rochaix J D
Department of Molecular Biology, University of Geneva, Switzerland.
EMBO J. 1992 May;11(5):1697-704. doi: 10.1002/j.1460-2075.1992.tb05220.x.
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.
叶绿素合成的不依赖光的途径发生在一些低等植物和藻类中，目前在很大程度上仍不为人所知。我们鉴定了莱茵衣藻的一个叶绿体突变体H13，它在黑暗中无法合成叶绿素，并且也缺乏光系统I。该突变体的叶绿体基因组有一个2.8 kb的缺失以及其他重排。通过用特定的野生型叶绿体DNA片段对H13进行粒子枪介导的叶绿体转化，我们鉴定出了一个新的叶绿体基因chlN，它编码一种545个氨基酸的蛋白质，该蛋白质参与叶绿素的不依赖光的积累，可能是在原叶绿素酸酯还原为叶绿素酸酯的步骤中发挥作用。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。
