Wobbe L. The molecular function of plant mTERFs as key regulators of organellar gene expression. Plant and Cell Physiology. 2020: pcaa132.The protein family of mTERFs (mitochondrial transcription termination factors) was initially studied in mammalian and insect mitochondria before the first Arabidopsis mTERF mutant was characterized. More than ten years of research on the function of plant mTERFs in the flowering plants A. thaliana, Z. mays and the green microalga C. reinhardtii has since highlighted that mTERFs are key regulators of organellar gene expression (OGE) in mitochondria as well as in chloroplasts. Additional functions to be fulfilled by plant mTERFs (e.g. splicing) and the fact that the expression of two organellar genomes had to be facilitated has led to a massive expansion of the plant mTERF portfolio compared to that found in mammals. Plant mTERFs are implicated in all steps of OGE ranging from the modulation of transcription to the maturation of tRNAs and hence translation. Furthermore, being regulators of OGE, mTERFs are required for a successful long-term acclimation to abiotic stress, retrograde signaling and interorganellar communication. Here, I review the recent progress in the elucidation of molecular mTERF functions
