Comparative Studies for Deducing Functions of Chloroplast Structures in Green Plants

绿色植物叶绿体结构功能推导的比较研究

基本信息

批准号：
11440241
负责人：
NOZAKI Hisayoshi
金额：
$ 8.77万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2002
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-11440241/
关键词：
Chloroplast Molecular phylogenetic analysis Morphological evolution rbcL genes Cellular function Green plants Ultrastructure Pyrenoid 機能推測遺伝子導入緑色植物 RbcLタンパク質 CO_2濃縮機構 atpB遺伝子 psaB遺伝子

项目摘要

The morphology of the pyrenoid and the physiology of the CO2-concentrating mechanism (CCM) were investigated in Chloromonas and related species of Chlamydomonas. Based on the results obtained, it was speculated that the presence of typical pyrenoids with a high concentration of Rubisco molecules is related to the formation of large Ci pools in the CCM. Detailed phylogenetic relationships among these Chlamydomonas/Chloromonas strains and the pyrenoid-less Chloromonas strains previously investigated were inferred based on the sequence of rbcL, the gene for the large subunit of Rubisco. Two monophyletic groups were resolved with high bootstrap values. Based on the tree topology resolved, it was inferred that loss of the typical pyrenoids accompanied by a decrease in intracellular Ci pools might have taken place independently in the two groups. This is the first demonstration of concrete function of the chloroplast structure pyrenoid.We further compared sequences of the rbcL genes of pyrenoid-less Chloromonas species with those of closely related pyrenoid-containing Chlamydomonas species in the "Chloromonas lineage" and with those of 45 other green algae. We found that the proteins encoded by the rbcL genes had a much higher level of amino acid substitution in members of the Chloromonas lineage than they did in other algae. A phylogenetic tree based on rbcL nucleotide sequences nested two Chlamydomonas species as a "pyrenoid-regained" clade within a monophyletic Chloromonas "pyrenoid-lost" clade. However, both the atpB and the psaB sequence data gave robust support for a rather different set of phylogenetic relationships in which neither the "pyrenoid-lost" nor the "pyrenoid-regained" clade was resolved. The appearance of such clades in the rbcL-based tree may be an artifact of convergent evolutionary changes that have occurred in a region of the large subunit that determines whether Rubisco molecules will aggregate to form a visible pyrenoid.

在衣原体的叶绿素及其相关物种中研究了二氧化碳的形态和二氧化碳浓度机制（CCM）的生理学。根据获得的结果，据推测，具有高浓度Rubisco分子的典型类拟南芥的存在与CCM中大型CI池的形成有关。这些衣原体/叶绿素菌株和无类叶绿素菌株的详细系统发育关系是根据RBCL的序列（Rubisco的大型亚基的基因）推断出来的。将两个单系组与高hootstrap值解析。基于树木拓扑结构的解决，可以推断出典型的类球形损失伴随着细胞内CI池减少的损失可能是在两组中独立发生的。这是叶绿体结构的混凝土功能的首次证明。我们进一步比较了无类叶酸叶绿素质物种的RBCL基因与“绿绿色素谱系”中的含孢子虫的衣原体物种的序列与密切相关的含类增生的衣原体物种的序列。我们发现，由RBCL基因编码的蛋白质在叶绿素谱系成员的氨基酸取代水平要高于其他藻类。基于RBCL核苷酸序列的系统发育树将两个衣原体物种嵌套在单属叶绿素叶绿素中“ pyrenaid-lost”进化枝中，作为一种“荷兰类药物恢复的”进化枝。但是，ATPB和PSAB序列数据均给予了相当不同的系统发育关系集的强大支持，在这种关系中，“ pyrenaid-lost”均未解决“ pyrenaioid-lost”和“碳酸类动物恢复的”进化枝。这种进化枝在基于RBCL的树中的出现可能是在大亚基的一个区域中发生的收敛进化变化的伪像，该区域决定了Rubisco分子是否会汇总以形成可见的孢子类。