N⁶-Methyladenosine RNA Modification Regulates Shoot Stem Cell Fate in Arabidopsis

Highlights

• FIP37 is a core component of the plant m⁶A methyltransferase complex

• FIP37 is essential for sculpting the global m⁶A mRNA modification landscape

• RNA modification mediated by FIP37 confines expression of key stem cell regulators

• fip37 mutants exhibit massive overproliferation of SAMs without aerial organs

Summary

N⁶-Methyladenosine (m⁶A) represents the most prevalent internal modification on mRNA and requires a multicomponent m⁶A methyltransferase complex in mammals. How their plant counterparts determine the global m⁶A modification landscape and its molecular link to plant development remain unknown. Here we show that FKBP12 INTERACTING PROTEIN 37 KD (FIP37) is a core component of the m⁶A methyltransferase complex, which underlies control of shoot stem cell fate in Arabidopsis. The mutants lacking FIP37 exhibit massive overproliferation of shoot meristems and a transcriptome-wide loss of m⁶A RNA modifications. We further demonstrate that FIP37 mediates m⁶A RNA modification on key shoot meristem genes inversely correlated with their mRNA stability, thus confining their transcript levels to prevent shoot meristem overproliferation. Our results suggest an indispensable role of FIP37 in mediating m⁶A mRNA modification, which is required for maintaining the shoot meristem as a renewable source for continuously producing all aerial organs in plants.