Meiotic exit in <i>Arabidopsis</i> is driven by P-body–mediated inhibition of translation
Albert Cairó, Anna Vargova, Neha Shukla, Cláudio Capitão, Pavlina Mikulková, Soňa Valuchová, Jana Pecinkova, Petra Bulánková, Karel Říha
Abstract
Meiosis, at the transition between diploid and haploid life cycle phases, is accompanied by reprograming of cell division machinery and followed by a transition back to mitosis. We show that, in Arabidopsis , this transition is driven by inhibition of translation, achieved by a mechanism that involves processing bodies (P-bodies). During the second meiotic division, the meiosis-specific protein THREE-DIVISION MUTANT 1 (TDM1) is incorporated into P-bodies through interaction with SUPPRESSOR WITH MORPHOGENETIC EFFECTS ON GENITALIA 7 (SMG7). TDM1 attracts eIF4F, the main translation initiation complex, temporarily sequestering it in P-bodies and inhibiting translation. The failure of tdm1 mutants to terminate meiosis can be overcome by chemical inhibition of translation. We propose that TDM1-containing P-bodies down-regulate expression of meiotic transcripts to facilitate transition of cell fates to postmeiotic gametophyte differentiation.