Gene

Meristem

Mutant

Cellular differentiation

Cell

Cell fate determination

Auxin

Shoot

Arabidopsis thaliana

Asymmetric cell division

Arabidopsis

Cytokinin

Stem cell

Genetics

Botany

Regulator

Cell division

Transcription factor

Biology

Cell biology

eLife

Plant meristems carry pools of continuously active stem cells, whose activity is controlled by developmental and environmental signals. After stem cell division, daughter cells that exit the stem cell domain acquire transit amplifying cell identity before they are incorporated into organs and differentiate. In this study, we used an integrated approach to elucidate the role of HECATE (HEC) genes in regulating developmental trajectories of shoot stem cells in Arabidopsis thaliana. Our work reveals that HEC function stabilizes cell fate in distinct zones of the shoot meristem thereby controlling the spatio-temporal dynamics of stem cell differentiation. Importantly, this activity is concomitant with the local modulation of cellular responses to cytokinin and auxin, two key phytohormones regulating cell behaviour. Mechanistically, we show that HEC factors transcriptionally control and physically interact with MONOPTEROS (MP), a key regulator of auxin signalling, and modulate the autocatalytic stabilization of auxin signalling output.

Control of plant cell fate transitions by transcriptional and hormonal signals