Identification and expression analysis of N6-methyltransferase and demethylase in rapeseed (Brassica napus L.)

Abstract

Abstract Background N 6 -methyladenosine (m6A) modification involves the addition of a methyl group to the nitrogen atom at position six of adenine in RNA. It is the most prevalent type of dynamic internal RNA methylation modification, plays an important role in plant development and abiotic stress. The m6A modification is facilitated by m6A writers (m6A methyltransferases), m6A erasers (m6A demethylation enzymes), and m6A readers (m6A methylated reading proteins). Results In order to study the characterization and expression of m6A methyltransferases and demethylases in Brassica napus (rapeseed), we used five methyltransferases and two demethylases from Arabidopsis thaliana as reference sequences. A total of 34 methyltransferases and 12 demethylases were identified in B. napus, B. oleracea, and B. rapa. We analyzed the physicochemical properties, gene structures, conserved domains, chromosome localization, and expression pattern across all tissues, as well as the effects of hormone and stress treatments on B. napus. Our findings revealed that the methyltransferase BnaHAKAI was highly expressed during the late stages of seed development. It may be related to the synthesis of oil content and seed size in the later stage of seed growth. In contrast, the demethylase BnaALKBH10B exhibited high expression primarily in the petals, followed by the pods, buds. This expression pattern may be associated with flower development and the timing of flowering. Furthermore, BnaALKBH10B primarily responded to abiotic stresses such as salinity, drought, osmotic, cold, and freezing, as well as to hormones like jasmonic acid and gibberellins. The qRT-PCR results showed that BnaALKBH10B responded to freezing and salt stress. Conclusions In summary, a total of 34 methyltransferases and 12 demethylases genes were identified in B. napus, B. oleracea, and B. rapa, and their phylogenetic relationships, structural domains, and expression patterns in tissues and under abiotic stress were comprehensively analyzed. This research will serve as a foundation for future studies on m6A in B. napus.

Keywords

• Brassica napus
• N6-methyladenosine
• Methyltransferase
• Demethylase
• Abiotic stress