Welchen Elina, García Lucila, Mansilla Natanael, Gonzalez Daniel H
Instituto de Agrobiotecnología del Litoral-Consejo Nacional de Investigaciones Científicas y Técnicas-Universidad Nacional del Litoral Santa Fe, Argentina ; Cátedra de Biología Celular y Molecular, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral Santa Fe, Argentina.
Front Plant Sci. 2014 Jan 8;4:551. doi: 10.3389/fpls.2013.00551.
Plant mitochondria are complex organelles that carry out numerous metabolic processes related with the generation of energy for cellular functions and the synthesis and degradation of several compounds. Mitochondria are semiautonomous and dynamic organelles changing in shape, number, and composition depending on tissue or developmental stage. The biogenesis of functional mitochondria requires the coordination of genes present both in the nucleus and the organelle. In addition, due to their central role, all processes held inside mitochondria must be finely coordinated with those in other organelles according to cellular demands. Coordination is achieved by transcriptional control of nuclear genes encoding mitochondrial proteins by specific transcription factors that recognize conserved elements in their promoter regions. In turn, the expression of most of these transcription factors is linked to developmental and environmental cues, according to the availability of nutrients, light-dark cycles, and warning signals generated in response to stress conditions. Among the signals impacting in the expression of nuclear genes, retrograde signals that originate inside mitochondria help to adjust mitochondrial biogenesis to organelle demands. Adding more complexity, several nuclear encoded proteins are dual localized to mitochondria and either chloroplasts or the nucleus. Dual targeting might establish a crosstalk between the nucleus and cell organelles to ensure a fine coordination of cellular activities. In this article, we discuss how the different levels of coordination of mitochondrial biogenesis interconnect to optimize the function of the organelle according to both internal and external demands.
植物线粒体是复杂的细胞器，执行许多与为细胞功能产生能量以及几种化合物的合成和降解相关的代谢过程。线粒体是半自主和动态的细胞器，其形状、数量和组成会根据组织或发育阶段而变化。功能性线粒体的生物发生需要细胞核和细胞器中基因的协调。此外，由于它们的核心作用，线粒体内部进行的所有过程都必须根据细胞需求与其他细胞器中的过程进行精细协调。这种协调是通过特定转录因子对编码线粒体蛋白的核基因进行转录控制来实现的，这些转录因子识别其启动子区域中的保守元件。反过来，这些转录因子中的大多数的表达与发育和环境线索相关，这取决于营养物质的可用性、光暗周期以及对压力条件产生的警告信号。在影响核基因表达的信号中，源自线粒体内的逆行信号有助于根据细胞器需求调整线粒体生物发生。更复杂的是，几种核编码蛋白可同时定位于线粒体以及叶绿体或细胞核。双重靶向可能会在细胞核和细胞器之间建立一种相互作用，以确保细胞活动的精细协调。在本文中，我们讨论线粒体生物发生的不同协调水平如何相互关联，以根据内部和外部需求优化细胞器的功能。
