Functional Characterization of a Putative RNA Demethylase ALKBH6 in Arabidopsis Growth and Abiotic Stress Responses.
RNA methylation and demethylation, which is mediated by RNA methyltransferases (referred to as "writers") and demethylases (referred to as "erasers"), respectively, are emerging as a key regulatory process in plant development and stress responses. Although several studies have shown that AlkB homolog (ALKBH) proteins are potential RNA demethylases, the function of most ALKBHs is yet to be determined. The Arabidopsis thaliana genome contains thirteen genes encoding ALKBH proteins, the functions of which are largely unknown. In this study, we characterized the function of a potential eraser protein, ALKBH6 (At4g20350), during seed germination and seedling growth in Arabidopsis under abiotic stresses. The seeds of T-DNA insertion alkbh6 knockdown mutants germinated faster than the wild-type seeds under cold, salt, or abscisic acid (ABA) treatment conditions but not under dehydration stress conditions. Although no differences in seedling and root growth were observed between the alkbh6 mutant and wild-type under normal conditions, the alkbh6 mutant showed a much lower survival rate than the wild-type under salt, drought, or heat stress. Cotyledon greening of the alkbh6 mutants was much higher than that of the wild-type upon ABA application. Moreover, the transcript levels of ABA signaling-related genes, including ABI3 and ABI4, were down-regulated in the alkbh6 mutant compared to wild-type plants. Importantly, the ALKBH6 protein had an ability to bind to both m6A-labeled and m5C-labeled RNAs. Collectively, these results indicate that the potential eraser ALKBH6 plays important roles in seed germination, seedling growth, and survival of Arabidopsis under abiotic stresses.
['Huong|Trinh Thi|TT|', 'Ngoc|Le Nguyen Tieu|LNT|', 'Kang|Hunseung|H|0000-0002-3532-7690']
D000040:Abscisic Acid D000071496:AlkB Enzymes D017360:Arabidopsis D029681:Arabidopsis Proteins D015536:Down-Regulation D055864:Droughts D018506:Gene Expression Regulation, Plant D018525:Germination D009154:Mutation D010937:Plant Growth Regulators D018517:Plant Roots D012313:RNA D036226:Seedlings D012639:Seeds D015398:Signal Transduction D012965:Sodium Chloride D013312:Stress, Physiological
Arabidopsis abiotic stress RNA methylation ALKBH RNA demethylation epitranscriptomics