show Abstracthide AbstractWe show that trm5 plants have less m1G in tRNAs, a slower leaf initiation rate, delayed flowering, and reduced primary root length. Late flowering correlates with reduced transcription of floral activators CO, FT, SOC1 and AP1. We also show that TRM5 methylates tRNA position 37 of several nucleus-encoded tRNA species, trm5 plants have reduced m1G and TRM5 is localized to the nucleus. Our findings highlight the importance of the post-transcriptional tRNA modification m1G37 in plant growth and development. Overall design: Identification of m1G methylation at position 37 of Arabidopsis thaliana tRNAs and Differential Expression analysis of wild type Col-0 Ecotype and trm5-1 mutant.