OsEDM2L mediates m<sup>6</sup>A of <i>EAT1</i> transcript for proper alternative splicing and polyadenylation regulating rice tapetal degradation
Kun Ma, Jingluan Han, Zixu Zhang, Heying Li, Yanchang Zhao, Qinlong Zhu, Yongyao Xie, Yao‐Guang Liu, Letian Chen
Abstract
Abstract N 6 ‐methyladenosine (m 6 A) modification affects the post‐transcriptional regulation of eukaryotic gene expression, but the underlying mechanisms and their effects in plants remain largely unknown. Here, we report that the N 6 ‐adenine methyltransferase‐like domain‐containing protein ENHANCED DOWNY MILDEW 2‐LIKE (OsEDM2L) is essential for rice ( Oryza sativa L.) anther development. The osedm2l knockout mutant showed delayed tapetal programmed cell death (PCD) and defective pollen development. OsEDM2L interacts with the transcription factors basic helix‐loop‐helix 142 and TAPETUM DEGENERATION RETARDATION to regulate the expression of ETERNAL TAPETUM 1 ( EAT1 ), a positive regulator of tapetal PCD. Mutation of OsEDM2L altered the transcriptomic m 6 A landscape, and caused a distinct m 6 A modification of the EAT1 transcript leading to dysregulation of its alternative splicing and polyadenylation, followed by suppression of the EAT1 target genes OsAP25 and OsAP37 for tapetal PCD. Therefore, OsEDM2L is indispensable for proper messenger RNA m 6 A modification in rice anther development.