Lsoprenoid biosynthesis authenticates the classification of the green alga Mesostigma viride as an ancient streptophyte
Lsoprenoid biosynthesis authenticates the classification of the green alga Mesostigma viride as an ancient streptophyte
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DOI：
10.1016/j.gene.2007.02.020
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发表时间：
2007-07-01
期刊：
影响因子：
3.5
通讯作者：
Petersen, Joern
中科院分区：
文献类型：
--
作者：
Grauvogel, Carina;Petersen, Joern
陆生植物类异戊二烯合成有两条基本的、完全不同的代谢途径。胞质甲羟戊酸途径（MVA）与异养真核生物共享，而质体2-C-甲基-d-d4-磷酸（MEP）途径具有蓝细菌起源，并且在初级内共生后被招募。陆生植物和绿色藻类具有共同的进化祖先，但生化和基因组分析表明，细胞溶质MVA途径通常不存在于绿藻门中。我们研究了链藻（轮藻纲绿色藻类，陆生植物）进化基础上的关键物种绿色中柱藻中这两条途径的基因分布。使用逆转录PCR方法用单独设计的简并引物扩增了12个类异戊二烯生物合成的通常弱表达的基因中的10个，包括3个胞质MVA途径的基因。通过文库筛选，从轮藻属的绿色普通轮藻中获得了MVA途径第一个酶（HMGS）的两个全长cDNA克隆。MVA途径在这些高级绿色藻中的存在表明在链藻门中普遍存在，我们的系统发育分析证实了中柱藻属与轮藻和陆生植物的最新分类。我们确定了每一个的5个细胞溶质MVA基因/cDNA的基因组中的红藻Galdieria sulphuraria，此外，扩增其中4个从蓝绿藻蓝藻paradoxa。我们的数据表明，MVA途径是植物的一个特征，并提出它是专门失去了一个共同的祖先绿藻。(c)2007 Elsevier B.V保留所有权利。
Land plants harbor two essential and completely different metabolic pathways for isoprenoid synthesis. The cytosolic mevalonate pathway (MVA) is shared with heterotrophic eukaryotes, whereas the plastidial 2-C-methyl-d-erythritol 4-phosphate (MEP) pathway has a cyanobacterial origin and was recruited after primary endosymbiosis. Terrestrial plants and green algae have a common evolutionary ancestry, but biochemical as well as genome analyses indicate that the cytosolic MVA pathway is generally absent from Chlorophyta. We investigated the distribution of genes for both pathways in the green alga Mesostigma viride, a key species at the basis of streptophycean (charophycean green algae, land plant) evolution. Ten of altogether twelve generally weakly expressed genes for isoprenoid biosynthesis, including three for the cytosolic MVA pathway, were amplified using a reverse transcription PCR approach with individually designed degenerate primers. Two full length cDNA clones for the first enzyme of the MVA pathway (HMGS) were additionally established from the charophycean green alga Chara vulgaris by library screening, The presence of the MVA pathway in these advanced green algae indicates a universal distribution among Streptophyta, and our phylogenetic HMGS analyses substantiate the recent classification of Mesostigma basal to charophytes and land plants. We identified each of the five cytosolic MVA genes/cDNAs in the genome of the rhodophyte Galdieria sulphuraria and, furthermore, amplified four of them from the glaucophyte Cyanophora paradoxa. Our data indicate that the MVA pathway is a characteristic trait of Plantae in general and propose that it was specifically lost in a common ancestor of Chlorophyta. (c) 2007 Elsevier B.V All rights reserved.