Laboratory of Physiological Genetics, Siberian Institute of Plant Physiology and Biochemistry, Siberian Branch of the Russian Academy of Sciences, 664033 Irkutsk, Russia.
Int J Mol Sci. 2023 Oct 16;24(20):15229. doi: 10.3390/ijms242015229.
The study of the supramolecular organization of the mitochondrial oxidative phosphorylation system (OXPHOS) in various eukaryotes has led to the accumulation of a considerable amount of data on the composition, stoichiometry, and architecture of its constituent superstructures. However, the link between the features of system arrangement and the biological characteristics of the studied organisms has been poorly explored. Here, we report a comparative investigation into supramolecular and functional OXPHOS organization in the mitochondria of etiolated shoots of winter wheat ( L.), maize ( L.), and pea ( L.). Investigations based on BN-PAGE, in-gel activity assays, and densitometric analysis revealed both similarities and specific OXPHOS features apparently related to the life strategies of each species. Frost-resistant winter wheat was distinguished by highly stable basic IIIIIVa/b respirasomes and V dimers, highly active complex I, and labile complex IV, which were probably essential for effective OXPHOS adaptation during hypothermia. Maize, a C4 plant, had the highly stable dimers IV and V, less active complex I, and active alternative NAD(P)H dehydrogenases. The latter fact could contribute to successful chloroplast-mitochondrial cooperation, which is essential for highly efficient photosynthesis in this species. The pea OXPHOS contained detergent-resistant high-molecular respirasomes IIIIIV, highly active complexes IV and V, and stable succinate dehydrogenase, suggesting an active energy metabolism in organelles of this plant. The results and conclusions are in good agreement with the literature data on the respiratory activity of mitochondria from these species and are summarized in a proposed scheme of organization of OXPHOS fragments.
对各种真核生物中线粒体氧化磷酸化系统（OXPHOS）的超分子组织的研究积累了相当多关于其组成、化学计量和组成超结构的结构的数据。然而，系统排列的特征与所研究生物体的生物学特征之间的联系还没有得到很好的探索。在这里，我们报告了对冬季小麦（L.）、玉米（L.）和豌豆（L.）黄化芽线粒体中超分子和功能 OXPHOS 组织的比较研究。基于 BN-PAGE、胶内活性测定和密度计分析的研究揭示了明显与每个物种的生活策略相关的 OXPHOS 特征的相似性和特异性。抗冻性强的冬小麦具有高度稳定的基本 IIIIIVa/b 呼吸体和 V 二聚体、高度活跃的复合物 I 和不稳定的复合物 IV，这可能对低温下有效的 OXPHOS 适应至关重要。玉米是一种 C4 植物，具有高度稳定的 IV 和 V 二聚体、不太活跃的复合物 I 和活跃的替代 NAD(P)H 脱氢酶。后一事实可能有助于叶绿体-线粒体合作的成功，这对该物种高效光合作用至关重要。豌豆 OXPHOS 含有耐去污剂的高分子呼吸体 IIIIIV、高度活跃的复合物 IV 和 V 以及稳定的琥珀酸脱氢酶，表明该植物细胞器中存在活跃的能量代谢。结果和结论与这些物种线粒体呼吸活性的文献数据非常一致，并在提出的 OXPHOS 片段组织方案中进行了总结。
