PT  - JOURNAL ARTICLE
AU  - Vandasue L. Rodrigues
AU  - Ulla Dolde
AU  - Daniel Straub
AU  - Tenai Eguen
AU  - Esther Botterweg-Paredes
AU  - Bin Sun
AU  - Shinyoung Hong
AU  - Moritz Graeff
AU  - Man-Wah Li
AU  - Joshua M. Gendron
AU  - Stephan Wenkel
TI  - Dissection of the microProtein miP1 floral repressor complex in Arabidopsis
AID  - 10.1101/258228
DP  - 2018 Jan 01
TA  - bioRxiv
PG  - 258228
4099  - http://biorxiv.org/content/early/2018/02/01/258228.short
4100  - http://biorxiv.org/content/early/2018/02/01/258228.full
AB  - MicroProteins have emerged as potent regulators of transcription factor activity. Here we use a combination of forward genetics and proteomics to dissect the miP1a/b microProtein complex that acts to delay the floral transition in Arabidopsis. The microProteins miP1a and miP1b can bridge an interaction between the flowering promoting factor CONSTANS (CO) and the TOPLESS (TPL) co-repressor protein to represses flowering. We find that the JUMONJI14 (JMJ14) histone demethylase is part of this repressor complex that can initiate chromatin changes in FLOWERING LOCUS T (FT) gene, the direct target of CO. Plants with mutations in JMJ14 exhibit an early flowering phenotype that is largely dependent on the activity of CO, supporting a role for CO in this repressive complex. When mis-expressed at the shoot apex, CO can induce early flowering only in the jmj14 background. Our results indicate that the repressor acts in the shoot apical meristem to keep it in an undifferentiated state until the leaf-derived florigen signal induces the conversion into a floral meristem.