Multilayered Regulation of Plastids and Mitochondria

Arimura, Shin-Ichi; Finkemeier, Iris; Kühn, Kristina; Takenaka, Mizuki

Abstract

Plastids and mitochondria, the powerhouses of plant cells, have long intrigued scientists due to their crucial role in supporting complex life on Earth. Despite their importance, these organelles are still regarded as the hidden gems in the box, as they are both difficult to analyze and manipulate. While the genomes of these organelles were fully sequenced much earlier than nuclear genomes, understanding their genetic systems has been delayed substantially. Plastids and mitochondria exhibit intriguing and distinctive features concerning genomic structure, mode of inheritance and hybrid expression systems that incorporate bacterial, phage-like and plant-specific components. Complex RNA maturation systems including 5ʹ and 3ʹ RNA processing, intron splicing and C-to-U RNA editing are also distinctive aspects of these organelles. Furthermore, there are unique systems of translational machinery, protein processing, maturation and turnover, as well as homeostasis regulation, including diverse post-translational modifications and protein complex assembly.