Cell-autonomously controlled ground tissue initiation by auxin in early Arabidopsis embryo ($)

MONOPTEROS is an auxin-response factor (ARF) that is necessary for root formation during early embryogenesis. Its activity is modulated by BODENLOS (BDL), an Aux/IAA protein that is degraded in the presence of auxin.  Möller et al. investigated the transcriptional targets of MP in very early embryos through the cell-specific expression of a stabilized BDL protein (bdl), which leads to a decrease in expression level of MP targets. The authors showed that MP targets include auxin-regulated genes and several transcription factors. Furthermore, they identified several MP targets that are crucial for ground tissue establishment, and showed that MP acts cell-autonomously in the specification of ground tissue and vascular tissue and that tissue initiation and tissue patterning can be regulated separately. Proc. Natl. Acad. Sci. 10.1073/pnas.1616493114