The shoot apical meristem （SAM） is a population of undifferentiated cells at the tip of the shoot axis that establishes early during plant embryogenesis and gives rise to all shoot organs throughout the plant＇s lif...The shoot apical meristem （SAM） is a population of undifferentiated cells at the tip of the shoot axis that establishes early during plant embryogenesis and gives rise to all shoot organs throughout the plant＇s life. A plethora of different families of transcription factors （TFs） play a key role in establishing the equilibrium between cell differentiation and stem cell maintenance in the SAM. Fine tuning of these regulatory proteins is crucial for a proper and fast SAM response to environmental and hormonal cues, and for development progression. One effective way to rapidly inactivate TFs involves regulated proteolysis by the ubiquitin/26S proteasome system （UPS）. However, a possible role of UPS-dependent protein degradation in the regulation of key SAM TFs has not been thoroughly investigated. Here, we summarize recent evidence supporting a role for the UPS in SAM maintenance and function. We integrate this survey with an in silico analysis of publicly-available microarray databases which identified ubiquitin ligases that are expressed in specific areas within the SAM, suggesting that they may regulate or act downstream of meristem-specific factors.展开更多
基金supported by the Executive Programme of Scientific and Technological Cooperation between Italy and China(2010-2012)of the Italian Ministry of Foreign Affairs(MAE),Direzione Generale per la Promozione e la Co-operazione Culturale,with the contribution of the Ministero dell'Istruzione dell'Università e della Ricerca(MIUR)Project:Control of substrate degradation in plant development and environmental responseby the Agri-food CNR strategic project(AG.P01.003):Genetic,Physiological and Molecular Basis of Development and Differentiation of Model and Crop Species of Interest to Agri-food in response to endogenous and environmental cues
文摘The shoot apical meristem （SAM） is a population of undifferentiated cells at the tip of the shoot axis that establishes early during plant embryogenesis and gives rise to all shoot organs throughout the plant＇s life. A plethora of different families of transcription factors （TFs） play a key role in establishing the equilibrium between cell differentiation and stem cell maintenance in the SAM. Fine tuning of these regulatory proteins is crucial for a proper and fast SAM response to environmental and hormonal cues, and for development progression. One effective way to rapidly inactivate TFs involves regulated proteolysis by the ubiquitin/26S proteasome system （UPS）. However, a possible role of UPS-dependent protein degradation in the regulation of key SAM TFs has not been thoroughly investigated. Here, we summarize recent evidence supporting a role for the UPS in SAM maintenance and function. We integrate this survey with an in silico analysis of publicly-available microarray databases which identified ubiquitin ligases that are expressed in specific areas within the SAM, suggesting that they may regulate or act downstream of meristem-specific factors.
