RNA N6-methyladenosine modification promotes auxin biosynthesis required for male meiosis in rice

Abstract

N⁶-methyladenosine (m⁶A) RNA modification confers an essential layer of gene regulation in living organisms, including plants; yet, the underlying mechanisms of its deposition on specific target mRNAs involved in key plant developmental processes are so far unknown. Here, we show that a core component of the rice m⁶A methyltransferase complex, OsFIP37, is recruited by an RNA-binding protein, OsFIP37-associated protein 1 (OsFAP1), to mediate m⁶A RNA modification on an auxin biosynthesis gene, OsYUCCA3, during microsporogenesis. This stabilizes OsYUCCA3 mRNA and promotes local auxin biosynthesis in anthers during male meiosis, which is essential for meiotic division and subsequent pollen development in rice. Loss of function of OsFAP1 causes dissociation of OsFIP37 with OsYUCCA3 and the resulting abolished m⁶A deposition on OsYUCCA3. Our findings reveal that OsFAP1-dependent m⁶A deposition on OsYUCCA3 by OsFIP37 constitutes a hitherto unknown link between RNA modification and hormonal control of male meiosis in plant reproductive development.

Keywords: RNA modification; RNA-binding protein; auxin biosynthesis; m(6)A; male fertility; male meiosis; rice.