Peanut AhmTERF1 Regulates Root Growth by Modulating Mitochondrial Abundance

Mitochondria are responsible for energy generation, as well as key metabolic and signaling pathways, and thus affect the entire developmental process of plants as well as their responses to stress. In metazoans, mitochondrial transcription termination factors (mTERFs) are known to regulate mitochondrial transcription. mTERFs have also been discovered in plants, but only a few of these proteins have been explored for their biological functions. Here, we report a role in root growth for mitochondria-associated protein AhmTERF1 in peanut (Arachis hypogaea L.). Overexpressing AhmTERF1 significantly stimulated the growth of peanut hairy roots and transgenic Arabidopsis. Surprisingly, AhmTERF1 is predominantly expressed in the root meristem where it increases mitochondrial abundance. AhmTERF1 binding to mtDNA was enriched in the RRN18 and RRN26 regions, suggesting it is related to the accumulation of mitochondrial ribosomes. Peanut is one of the main oil crops and the important source of edible oil and AhmTERF1 likely affects agronomic traits related to root growth in different peanut cultivars. We propose that peanut AhmTERF1 is an important protein for root growth due to its role in regulating mitochondrial abundance.