Robust control of floral meristem determinacy by position-specific multifunctions of KNUCKLES
Erlei Shang, Xin Wang, Tinghan Li, Fengfei Guo, Toshiro Ito, Bo Sun
Abstract
Significance In floral meristem (FM), the transcription factor (TF) WUS and the secreted peptide CLV3 form a feedback loop to maintain robust stem cell activities. We found that the TF KNU is a temporally regulated repressor of WUS . However, how the spatial expression patterns of CLV3 and WUS are fully extinguished during floral organogenesis is unknown. Here, we show that KNU has position-specific multifunctions that achieve termination of robust FM. Besides repressing WUS in the organizing center, in the central zone, KNU directly represses CLV3 and inhibits WUS from sustaining CLV3 . Furthermore, KNU represses CLV1 and disrupts WUS–WUS and WUS–HAM1 interactions. Thus, KNU plays an essential role to promote FM determinacy for the proper formation of floral reproductive organs.