查看文章

Heteroblasty refers to a phenomenon that a plant produces morphologically or functionally different lateral organs in an age‐dependent manner. In the model plant Arabidopsis thaliana, the production of trichomes (epidermal leaf hairs) on the abaxial (lower) side of leaves is a heteroblastic mark for the juvenile‐to‐adult transition. Here, we show that the heteroblastic development of abaxial trichomes is regulated by a spatiotemporally regulated complex comprising the leaf abaxial fate determinant (KAN1) and the developmental timer (miR172‐targeted AP2‐like proteins). We provide evidence that a short‐distance chromatin loop brings the downstream enhancer element into close association with the promoter elements of GL1, which encodes a MYB transcription factor essential for trichome initiation. During juvenile phase, the KAN1‐AP2 repressive complex binds to the downstream sequence of GL1 and …