FIONA1 is an N6-methyladenosine methyltransferase that plays a vital role in floral transition via affecting the splicing of FLC and the stability of SPL3 and SEP3 in Arabidopsis.
Cai JingJianzhong HuUmme AmaraSu Jung ParkYuxia LiDaesong JeongIlha LeeTao XuHunseung KangPublished in: Journal of experimental botany (2022)
N 6-methyladenosine (m 6A) RNA methylation has been shown to play a crucial role in plant development and floral transition. Two recent studies have identified FIONA1 as an m 6A methyltransferase that regulates the floral transition via influencing the stability of CONSTANS (CO), SUPPRESSOR OF OVEREXPRESSION OF CONSTANS 1 (SOC1), and FLOWERING LOCUS C (FLC) in Arabidopsis. In this study, we confirmed that FIONA1 is an m 6A methyltransferase that installs m 6A marks in a small group of mRNAs. Furthermore, in addition to its role in influencing the stability of CO, SOC1, and FLC, we show that FIONA1-mediated m 6A methylation influences the splicing of FLC, a key floral repressor, and the stability of SQUAMOSA PROMOTER-BINDING PROTEIN-LIKE 3 (SPL3) and SEPALLATA3 (SEP3), floral activators, which plays a vital role in the floral transition in Arabidopsis. Our study confirms FIONA1 as an m 6A methyltransferase and suggests a close molecular link between FIONA1-mediated m 6A methylation and the splicing of FLC and the destabilization of SPL3 and SEP3 in flowering time control.