Hagemann Martin, Kern Ramona, Maurino Veronica G, Hanson David T, Weber Andreas P M, Sage Rowan F, Bauwe Hermann
Universität Rostock, Institut für Biowissenschaften, Abteilung Pflanzenphysiologie, A.- Einstein-Str. 3, D-18051 Rostock, Germany
Universität Rostock, Institut für Biowissenschaften, Abteilung Pflanzenphysiologie, A.- Einstein-Str. 3, D-18051 Rostock, Germany.
J Exp Bot. 2016 May;67(10):2963-76. doi: 10.1093/jxb/erw063. Epub 2016 Mar 1.
Photorespiration and oxygenic photosynthesis are intimately linked processes. It has been shown that under the present day atmospheric conditions cyanobacteria and all eukaryotic phototrophs need functional photorespiration to grow autotrophically. The question arises as to when this essential partnership evolved, i.e. can we assume a coevolution of both processes from the beginning or did photorespiration evolve later to compensate for the generation of 2-phosphoglycolate (2PG) due to Rubisco's oxygenase reaction? This question is mainly discussed here using phylogenetic analysis of proteins involved in the 2PG metabolism and the acquisition of different carbon concentrating mechanisms (CCMs). The phylogenies revealed that the enzymes involved in the photorespiration of vascular plants have diverse origins, with some proteins acquired from cyanobacteria as ancestors of the chloroplasts and others from heterotrophic bacteria as ancestors of mitochondria in the plant cell. Only phosphoglycolate phosphatase was found to originate from Archaea. Notably glaucophyte algae, the earliest branching lineage of Archaeplastida, contain more photorespiratory enzymes of cyanobacterial origin than other algal lineages or land plants indicating a larger initial contribution of cyanobacterial-derived proteins to eukaryotic photorespiration. The acquisition of CCMs is discussed as a proxy for assessing the timing of periods when photorespiratory activity may have been enhanced. The existence of CCMs also had marked influence on the structure and function of photorespiration. Here, we discuss evidence for an early and continuous coevolution of photorespiration, CCMs and photosynthesis starting from cyanobacteria via algae, to land plants.
光呼吸作用与产氧光合作用是紧密相连的过程。研究表明,在当今大气条件下,蓝细菌和所有真核光合生物进行自养生长都需要功能性的光呼吸作用。问题在于这种重要的协同关系是何时演化而来的,也就是说,我们能否假定这两个过程从一开始就是共同演化的,还是光呼吸作用是后来演化出来以补偿由于核酮糖-1,5-二磷酸羧化酶加氧酶反应产生的2-磷酸乙醇酸(2PG)?本文主要通过对参与2PG代谢的蛋白质进行系统发育分析以及对不同碳浓缩机制(CCMs)的获得情况来探讨这个问题。系统发育分析表明,维管植物光呼吸作用中涉及的酶有不同的起源,一些蛋白质是从作为叶绿体祖先的蓝细菌获得的,而另一些则是从作为植物细胞线粒体祖先的异养细菌获得的。仅发现磷酸乙醇酸磷酸酶起源于古菌。值得注意的是,灰胞藻作为原始色素体生物最早分支的谱系,与其他藻类谱系或陆地植物相比,含有更多起源于蓝细菌的光呼吸酶,这表明蓝细菌衍生的蛋白质对真核生物光呼吸作用的初始贡献更大。对CCMs获得情况的讨论被用作评估光呼吸活性可能增强时期的时间的一个指标。CCMs的存在也对光呼吸作用的结构和功能产生了显著影响。在这里,我们讨论了从蓝细菌经藻类到陆地植物,光呼吸作用、CCMs和光合作用早期且持续共同演化的证据。