Pluripotency acquisition in the middle cell layer of callus is required for organ regeneration
Pluripotency acquisition in the middle cell layer of callus is required for organ regeneration
复制标题
器官再生需要愈伤组织中细胞层的多能性获得
DOI：
10.1038/s41477-021-01015-8
复制
发表时间：
2021-11-01
期刊：
影响因子：
18
通讯作者：
Xu, Lin
中科院分区：
文献类型：
--
作者：
Zhai, Ning;Xu, Lin
在植物组织培养中，愈伤组织是在愈伤组织诱导培养基上以高生长素与低细胞分裂素的比例从离体外植体形成的。愈伤组织是一组多能性细胞，因为它可以分别响应于根诱导培养基上低水平的生长素或芽诱导培养基上高细胞分裂素与低生长素的比例而再生根或芽。然而，我们对愈伤组织形成过程中多能性获得机制的认识是有限的。在单细胞水平上的分析表明，拟南芥愈伤组织在愈伤组织诱导培养基上的组织结构类似于根原基或根尖分生组织，具有类似静止中心转录特征的中间细胞层具有器官再生能力。在中间细胞层，WUSCHEL相关同源框5（WOX5）直接与侧耳1和侧耳2相互作用，促进拟南芥色氨酸氨基转移酶1的表达，以产生内源性生长素。WOX5还与B型拟南芥反应调节因子12（ARR12）相互作用，并抑制A型ARR以破坏细胞分裂素信号传导中的负反馈环。总之，促进生长素的产生和增强细胞分裂素的敏感性都需要在愈伤组织的中间细胞层的器官再生的多能性收购。
In plant tissue culture, callus forms from detached explants in response to a high-auxin-to-low-cytokinin ratio on callus-inducing medium. Callus is a group of pluripotent cells because it can regenerate either roots or shoots in response to a low level of auxin on root-inducing medium or a high-cytokinin-to-low-auxin ratio on shoot-inducing medium, respectively. However, our knowledge of the mechanism of pluripotency acquisition during callus formation is limited. On the basis of analyses at the single-cell level, we show that the tissue structure ofArabidopsis thalianacallus on callus-inducing medium is similar to that of the root primordium or root apical meristem, and the middle cell layer with quiescent centre-like transcriptional identity exhibits the ability to regenerate organs. In the middle cell layer, WUSCHEL-RELATED HOMEOBOX5 (WOX5) directly interacts with PLETHORA1 and 2 to promoteTRYPTOPHAN AMINOTRANSFERASE OF ARABIDOPSIS1expression for endogenous auxin production. WOX5 also interacts with the B-type ARABIDOPSIS RESPONSE REGULATOR12 (ARR12) and represses A-typeARRs to break the negative feedback loop in cytokinin signalling. Overall, the promotion of auxin production and the enhancement of cytokinin sensitivity are both required for pluripotency acquisition in the middle cell layer of callus for organ regeneration.