A transcriptional module for auxin-mediated floral initiation

Auxin is required for flower development, but the exact mechanisms by which auxin controls floral initiation have not been solved. Several Arabidopsis mutants including pin1, pid, mp, and npy fail to develop flowers, resulting in pin-like inflorescences. PIN1 is an auxin efflux carrier localized on plasma membrane whereas MP is a transcriptional factor. Mechanistic links between PIN-mediated auxin transport and transcriptional regulation of auxin-mediated organogenesis are not understood. Recently, we have shown that PID, a protein kinase, regulates PIN-mediated auxin transport indirectly and negatively through NPYs, whose biochemical activity is not known. In this presentation, I show that transcription factors belonging to the ENHANCER OF SHOOT REGENERATION (ESR) family play an essential role in flower initiation in Arabidopsis thaliana. Inactivation of a sub-set of ESR transcription factors leads to the development of pin-like inflorescences. Our findings indicate that these transcription factors participate in the auxin signaling pathway and play an indispensable role in the response to auxin maxima. Furthermore, we identified putative ESR2 target genes and demonstrate that one of them, KSN which encodes a protein kinase, is sufficient to suppress the flower initiation defects of the esr triple mutants when overexpressed. Our studies establish essential components of plant organogenesis and provide new avenues for further probing the complex system of auxin-mediated floral development.

講者: Dr. Yunde Zhao (Tata Chancellor’s Endowed Professor, Professor of Cell and Developmental Biology, University of California San Diego, USA)

主持人: Dr. Choun-Sea Lin

時間:2026/07/01 13:30 PM

地點:農業科技大樓1樓A134演講廳