[植物生理] 植物分生組織的調控機制。20191126 Nautre communication

Plasmodesmata
Nov 26, 2019
2 min read

WUSCHEL acts as an auxin response rheostat to maintain apical stem cells in Arabidopsis

Yanfei Ma, Andrej Miotk, Zoran Šutiković, Olga Ermakova, Christian Wenz, Anna Medzihradszky, Christophe Gaillochet, Joachim Forner, Gözde Utan1, Klaus Brackmann, Carlos S. Galván-Ampudia, Teva Vernoux, Thomas Greb & Jan U. Lohmann

Abstract

To maintain the balance between long-term stem cell self-renewal and differentiation, dynamic signals need to be translated into spatially precise and temporally stable gene expression states. In the apical plant stem cell system, local accumulation of the small, highly mobile phytohormone auxin triggers differentiation while at the same time, pluripotent stem cells are maintained throughout the entire life-cycle. We find that stem cells are resistant to auxin mediated differentiation, but require low levels of signaling for their maintenance. We demonstrate that the WUSCHEL transcription factor confers this behavior by rheostatically controlling the auxin signaling and response pathway. Finally, we show that WUSCHEL acts via regulation of histone acetylation at target loci, including those with functions in the auxin pathway. Our results reveal an important mechanism that allows cells to differentially translate a potent and highly dynamic developmental signal into stable cell behavior with high spatial precision and temporal robustness.

WUSCHEL在阿拉伯芥中，扮演著生長素反應電阻的角色，來維持莖頂分生組織的發育

摘要

為了要長期維持幹細胞的自我更新與分化間的平衡，動態的訊息必須要被轉譯成，在空間上很準確、在時間上很穩定的基因表現。在植物尖端的幹細胞系統，區域性累積微小卻具有高度移動性的植物荷爾蒙生長素，可以促進細胞分化。但是同時，多潛能性的幹細胞也必須在整個生長週期中被維持。我們發現，幹細胞可以抵抗生長素所調節的細胞分化機制，但是同時也必須要有低水平的訊息傳導來維持細胞的身份。我們展示了WUSCHEL轉錄因子會像電阻般調節生長素訊息傳導及反應，來給予植物莖頂分生組織有分化卻也維持幹細胞這樣的生長行為模式。最後，我們呈現WUSCHEL經由催化特定基因位置組織蛋白（histone）的乙醯修飾，包含那些在生長素反應路徑中的基因，來調節細胞的反應。我們的結果顯示了一個重要的機制，這個機制使得細胞將一個有高度影響力並且非常動態的生長訊息，轉譯成穩定確有高度空間上的準確性與時間上很穩定的細胞行為。