A study published in The EMBO Journal by researchers from the IBMP (CNRS, University of Strasbourg) reveals how transfer RNA (tRNA) gene repertoires have evolved in photosynthetic organisms, particularly Archaeplastida, to adapt to ecological transitions, genomic constraints, and translational demands.
The findings show that terrestrialization marked a turning point in tRNA evolution, with:
- The loss of selenocysteine and its dedicated tRNA in land plants, which are absent in algae.
- Changes in the prevalence and structure of introns, reflecting adaptation to new environmental constraints.
- A correlation between tRNA gene copy number, codon usage, and amino acid composition, with reinforced cis-regulatory elements in angiosperms, consistent with increased translational demands.
The researchers also highlight that plant tRNA genes are generally evenly dispersed throughout the genome, unlike in some algae, where clustered configurations are more common.
These observations support a model in which tRNA gene repertoires act as drivers of genome evolution, integrating translational demand, genomic organization, and ecological adaptation across photosynthetic lineages.
