The cellular epitranscriptome

Vicente, Alexandre Magno (2022): The cellular epitranscriptome: analysis of N6-methyladenosine (m6A) in Arabidopsis thaliana RNAs upon acclimation. Dissertation, LMU München: Fakultät für Biologie

Abstract

Several chemical modifications in cellular RNAs have been identified to date. The most common internal modification of eukaryotic RNAs is known as m6A. This modification is able to configure the outcome of gene expression by adjusting RNA decay, translation efficiency, RNA structure and alternative splicing. Although thousands of m6A sites were found in RNAs of several plant species, nearly nothing is known about the impact of m6A on plant acclimation. Here, we showed that mRNAs encoding writers, erasers and readers - proteins capable of installing, removing and recognizing/interpreting RNA modifications, respectively, - are responsive to cold, heat and high light conditions in Arabidopsis thaliana. Quantification of m6A by mass spectrometric analysis showed that m6A-modified poly(A)-enriched mRNAs are more abundant under cold acclimation. Under this condition, knockdown lines for components of the major m6A writer complex showed a decrease in photosynthetic performance, especially in the fip37-4 mutant. Immunological analysis of photosynthetic proteins and blue native gels has shown that under cold specific proteins and supercomplexes are downregulated in fip37-4. Interestingly, fip37-4 has a further role in thylakoid organization under cold as revealed by chloroplast ultrastructure analysis. In addition, ROS formation was increased while the expression of cold acclimation-related genes was reduced in fip37-4 at low temperatures. Plant development regarding leaf area, weight, chlorophyll/anthocyanin content and root development was impaired under control, but a much stronger deficiency especially in photosynthesis was clear under cold acclimation. Altogether, these results indicate that FIP37-based RNA methylations play crucial roles in plastid functions under cold and several other aspects of plant development.

• Dokumententyp: Dissertationen (Dissertation, LMU München)
• Themengebiete: 500 Naturwissenschaften und Mathematik ; 500 Naturwissenschaften und Mathematik > 570 Biowissenschaften, Biologie
• Fakultäten: Fakultät für Biologie
• Sprache der Hochschulschrift: Englisch
• Datum der mündlichen Prüfung: 4. Oktober 2022
• 1. Bericht­erstatter:in: Meurer, Jörg