Mutation of an Essential 60S Ribosome Assembly Factor MIDASIN 1 Induces Early Flowering in .

Ribosome biogenesis is tightly associated with plant growth and reproduction. Mutations in genes encoding ribosomal proteins (RPs) or ribosome biogenesis factors (RBFs) generally result in retarded growth and delayed flowering. However, the early-flowering phenotype resulting from the ribosome biogenesis defect is rarely reported. We previously identified that the AAA-ATPase MIDASIN 1 (MDN1) functions as a 60S RBF in . Here, we found that its weak mutant is early-flowering. Transcriptomic analysis showed that the expression of () is down-regulated, while that of some autonomous pathway genes and () is up-regulated in . Phenotypic analysis revealed that the flowering time of is severely delayed by increasing expression, suggesting that the early flowering in is likely associated with the downregulation of . We also found that the photoperiod pathway downstream of () and () might contribute to the early flowering in . Intriguingly, the allele completely blocks the early flowering in . Collectively, our results indicate that the ribosome biogenesis defect elicited by the mutation of MDN1 leads to early flowering by affecting multiple flowering regulation pathways.