| Popis: |
How organisms control when to transition between different stages of development is a key question in biology. In plants, epigenetic silencing by Polycomb repressive complex 1 (PRC1) and PRC2 plays a crucial role in promoting developmental transitions, including from juvenile-to-adult phases of vegetative growth. PRC1/2 are known to repress the master regulator of vegetative phase change, miR156, leading to the transition to adult growth, but how this process is regulated temporally is unknown. Here we investigate whether transcription factors in theVIVIPAROUS/ABI3-LIKE(VAL) gene family provide the temporal signal for the epigenetic repression of miR156. Exploiting a novelval1allele, we found thatVAL1andVAL2redundantly regulate vegetative phase change by controlling the overall level, rather than temporal dynamics, of miR156 expression. Furthermore, we discovered thatVAL1andVAL2also act independently of miR156 to control this important developmental transition. |
