AtTRM11 as a tRNA 2-methylguanosine methyltransferase modulates flowering and bacterial resistance via translational regulation

Abstract

2-methylguanosine is an eukaryote-specific modified nucleoside in transfer RNAs, and m²G10 is catalyzed by Trm11-Trm112 protein complex in eukaryotic tRNAs. Here, we show that loss-of-function mutation of the Arabidopsis Trm11 homolog AtTRM11 resulted in m²G deficiency associated with disturbed ribosome assembly and overall transcriptome changes, including genes involved in flowering regulation and plant-pathogen interaction. The attrm11 mutant showed phenotypes of enlarged rosette leaves and early flowering, as well as enhanced resistance to Pseudomonas bacterial infection. AtTRM11 could partially rescue the m²G nucleoside level in yeast trm11 mutant, and AtTRM11 protein mostly resided in cytosol and physically interacted with AtTRM112b in planta. AtTRM11 was mostly expressed in shoot apex, root tip, and distal end of rosette leaves. KEGG enrichment analysis of differentially expressed genes between trm11 mutant and wild type indicated changes in pathways including phenopropanoid biosynthesis, plant-pathogen interaction, plant hormone signal transduction and MAPK signaling, suggesting that the pleiotropic phenotypes of the attrm11 mutant can be ascribed to translational and transcriptional changes.