Loss of tRNA uridine thiolation affects mRNA translation, protein production, and metabolite accumulation in Arabidopsis.

It is well established in yeast and animal system that the level of uridine thiolation at position 34 of tRNA anticodon loops can impact the decoding potential of the corresponding codons. Using Arabidopsis thaliana, we confirm that the ability of the plant ribosome to decode AAA, GAA, and CAA codons is impaired when this thiol group is lost, leading to a reduction in protein production, especially for genes enriched in these codons. Interestingly, we observed that loss of tRNA thiolation results in variations in the levels of numerous proteins involved in sulfur-compound metabolism and amino acid biosynthesis. These variations, in turn, affect the accumulation of several sulfur-containing metabolites and amino acids, suggesting that the level of tRNA thiolation has a direct and profound impact on plant metabolism. We also demonstrate that U34 thiolation is essential for adjusting plant growth in response to sulfur limitation and that its absence directly affects the plant's interaction with bacteria, including both pathogens and beneficial organisms. Our results support the hypothesis that the level of tRNA thiolation can be used in plant to link nutritional status to translation.