Rojas-Méndez Karla J, Sánchez Segura Lino, Chagolla Alicia, Lino Bárbara, González de la Vara Luis E
Laboratorio de Bioenergética y Biomembranas, Departamento de Biotecnología y Bioquímica, Unidad Irapuato, Centro de Investigación y de Estudios Avanzados del IPN, Irapuato, Mexico.
Laboratorio de Microscopía, Departamento de Ingeniería Genética, Unidad Irapuato, Centro de Investigación y de Estudios Avanzados del IPN, Irapuato, Mexico.
Front Plant Sci. 2021 Sep 8;12:714847. doi: 10.3389/fpls.2021.714847. eCollection 2021.
In plants, programmed cell death (PCD) is involved in both the development and the response to biotic and abiotic aggressions. In early stages of PCD, mitochondrial membranes are made permeable by the formation of permeability transition pores, whose protein composition is debated. Cytochrome c (cyt c) is then released from mitochondria, inducing the degradation of chromatin characteristic of PCD. Since flooding stress can produce PCD in several plant species, the first goal of this study was to know if flooding stress could be used to induce PCD in roots. To do this, 2-month-old beet plants were flood-stressed from 1 to 5 days, and the alterations indicating PCD in stressed beetroot cells were observed with a confocal fluorescence microscope. As expected, nuclei were deformed, and chromatin was condensed and fragmented in flooded beetroots. In addition, cyt c was released from mitochondria. After assessing that flood stress induced PCD in beetroots, the composition of mitochondrial protein complexes was observed in control and flood-stressed beetroots. Protein complexes from isolated mitochondria were separated by native gel electrophoresis, and their proteins were identified by mass spectrometry. The spectra count of three isoforms of voltage-dependent anion-selective channels (VDACs) increased after 1 day of flooding. In addition, the size of the complexes formed by VDAC was higher in flood-stressed beetroots for 1 day (∼200 kDa) compared with non-stressed ones (∼100 kDa). Other proteins, such as chaperonin CPN60-2, also formed complexes with different masses in control and flood-stressed beetroots. Finally, possible interactions of VDAC with other proteins were found performing a cluster analysis. These results indicate that mitochondrial protein complexes formed by VDAC could be involved in the process of PCD in flood-stressed beetroots. Data are available ProteomeXchange with identifier PXD027781.
在植物中，程序性细胞死亡（PCD）参与了植物的发育以及对生物和非生物侵害的响应。在PCD的早期阶段，线粒体膜通过形成通透性转换孔而变得具有通透性，其蛋白质组成存在争议。然后细胞色素c（cyt c）从线粒体中释放出来，诱导PCD特有的染色质降解。由于淹水胁迫可在多种植物物种中产生PCD，本研究的首要目标是了解淹水胁迫是否可用于诱导根中的PCD。为此，对2月龄的甜菜植株进行1至5天的淹水胁迫处理，并用共聚焦荧光显微镜观察受胁迫甜菜根细胞中指示PCD的变化。正如预期的那样，淹水甜菜根中的细胞核发生变形，染色质浓缩并碎片化。此外，cyt c从线粒体中释放出来。在评估淹水胁迫诱导甜菜根中的PCD后，观察了对照和淹水胁迫甜菜根中线粒体蛋白复合物的组成。通过非变性凝胶电泳分离来自分离线粒体的蛋白复合物，并通过质谱鉴定其蛋白质。淹水1天后，电压依赖性阴离子选择性通道（VDAC）三种同工型的光谱计数增加。此外，与未受胁迫的甜菜根（约100 kDa）相比，淹水胁迫1天的甜菜根中由VDAC形成的复合物尺寸更大（约200 kDa）。其他蛋白质，如伴侣蛋白CPN60 - 2，在对照和淹水胁迫的甜菜根中也形成了不同质量的复合物。最后，通过聚类分析发现了VDAC与其他蛋白质之间可能的相互作用。这些结果表明，由VDAC形成的线粒体蛋白复合物可能参与了淹水胁迫甜菜根中的PCD过程。数据可在ProteomeXchange上获取，标识符为PXD027781。
