TCP transcription factors determine the region where meristem forms during embryogenesis, and thus play a pivotal role in pattern formation ( Koyama et al., 2007, 2010). These include members of the TEOSINTE BRANCHED1/CYCLOIDEA/PROLIFERATING CELL FACTOR (TCP), WUSCHEL (WUS), and WOUND INDUCED DEDIFFERENTIATION (WIND) families. Recent work has identified several key transcription factors that induce cell dedifferentiation. A single callus cell can regenerate a whole plant, as shown by carrot somatic embryogenesis ( Nomura and Komamine, 1986). In contrast to mammalian cells, plant cells can alter their cell fate and differentiated somatic cells easily dedifferentiate to form masses of totipotent cells, called callus, following treatment with the phytohormones auxin and cytokinin. Therefore, the technology to produce iPS (induced Pluripotent Stem) cells by expressing specific transcription factors represents a significant breakthrough for animal research ( Takahashi and Yamanaka, 2006). Generally, differentiated mammalian cells cannot alter their fate or dedifferentiate to acquire pluripotency. We describe here the functions of TCP, WUS, and WIND transcription factors in the regulation of differentiation-dedifferentiation by positive and negative transcriptional regulators.
#Srdx as a suppressor for transcription factors Activator#
Interestingly, TCP is a transcriptional activator that acts as a negative regulator of shoot meristem formation, and WUS is a transcriptional repressor that positively maintains totipotency of the stem cells of the shoot meristem. WUS and WIND positively control plant cell totipotency, while TCP negatively controls it.
Recently, several plant transcription factors that regulate meristem formation and dedifferentiation have been identified and include members of the TEOSINTE BRANCHED1/CYCLOIDEA/PROLIFERATING CELL FACTOR (TCP), WUSCHEL (WUS), and WOUND INDUCED DEDIFFERENTIATION (WIND1) families. However, the regulatory mechanisms and key factors that control differentiation-dedifferentiation and cell totipotency have not been completely clarified in plants. In contrast to somatic mammalian cells, which cannot alter their fate, plant cells can dedifferentiate to form totipotent callus cells and regenerate a whole plant, following treatment with specific phytohormones. 2Research Institute of Bioproduction, National Institute of Advanced Industrial Science and Technology, Tsukuba, Japan.1Division of Strategic Research and Development, Graduate School of Science and Engineering, Satitama University, Saitama, Japan.
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