Arabidopsis T-DNA mutants affected in TRDMT1/DNMT2 show differential protein synthesis and compromised stress tolerance

• Published in: The FEBS journal 2024-01, Vol.291 (1), p.92-113
• Main Authors: Wadhwa, Nikita, Kapoor, Sanjay, Kapoor, Meenu
• Format: Article
• Language: English
• Subjects: Arabidopsis; Arabidopsis - genetics; Arabidopsis - metabolism; Chromatography, Liquid; Cytoplasm; DNA; DNA (Cytosine-5-)-Methyltransferases - genetics; DNA (Cytosine-5-)-Methyltransferases - metabolism; DNA-directed RNA polymerase; Flowering; Flowering plants; Homeostasis; Metabolic pathways; Metabolism; Methyltransferases; Mutants; Nucleic acids; Osmotic stress; Plants - metabolism; Protein biosynthesis; Protein synthesis; Proteins; Proteomes; Ribonucleic acid; RNA; RNA processing; RNA, Transfer - genetics; RNA, Transfer - metabolism; Signal transduction; Tandem Mass Spectrometry
• ISSN: 1742-464X; 1742-4658
• DOI: 10.1111/febs.16935

TRDMT1/DNMT2 belongs to the conserved family of nucleic acid methyltransferases. Unlike the animal systems, studies on TRDMT1/DNMT2 in land plants have been limited. We show that TRDMT1/DNMT2 is strongly conserved in the green lineage. Studies in mosses have previously shown that TRDMT1/DNMT2 plays a crucial role in modulating molecular networks involved in stress perception and signalling and in transcription/stability of specific tRNAs under stress. To gain deeper insight into its biological roles in a flowering plant, we examined more closely the previously reported Arabidopsis SALK_136635C line deficient in TRDMT1/DNMT2 function [Goll MG et al. (2006) Science 311, 395-398]. RNAs derived from Arabidopsis Dnmt2-deficient plants lacked m C38 in tRNA . In this study, by transient expression assays we show that Arabidopsis TRDMT1/DNMT2 is distributed in the nucleus, cytoplasm and RNA-processing bodies, suggesting a role for TRDMT1/DNMT2 in RNA metabolic processes possibly by shuttling between cellular compartments. Bright-field and high-resolution SEM and qPCR analysis reveal roles of TRDMT1/DNMT2 in proper growth and developmental progression. Quantitative proteome analysis by LC-MS/MS coupled with qPCR shows AtTRDMT1/AtDNMT2 function to be crucial for protein synthesis and cellular homeostasis via housekeeping roles and proteins with poly-Asp stretches and RNA pol II activity on selected genes are affected in attrdmt1/atdnmt2. This shift in metabolic pathways primes the mutant plants to become increasingly sensitive to oxidative and osmotic stress. Taken together, our study sheds light on the mechanistic role of TRDMT1/DNMT2 in a flowering plant.