背景回顾：Stem cell populations in all multicellular organisms are situated in a niche, which is a special microenvironment that defines stem cell fate. The interplay between stem cells and their niches is crucial for stem cell maintenance. 

结果1-ESS信号：Here, we show that an endogenous stress-related signal (ESS) is overrepresented in the shoot stem cell niche under natural growth conditions, and the vast majority of known stem-cell-specific and niche-specific genes responded to stress signals. 

结果2-乙烯信号-AGL22：Interference with the ESS in the stem cell niche by blocking ethylene signalling impaired stem cell maintenance. Ethylene-insensitive 3 (EIN3), the key transcription factor in ethylene signalling, directly actives the expression of the stress hub transcription factor AGAMOUS-LIKE 22 (AGL22) in the stem cell niche and relays ESS signals to the WUSCHEL/CLAVATA network.

结论：Our results provide a mechanistic framework for ESS signalling control of the stem cell niche and demonstrate that plant stem cells are maintained by a native stress microenvironment in vivo.

 摘 要 

所有多细胞生物中的干细胞群都位于一个niche中，这是一个决定干细胞命运的特殊微环境。干细胞与其niche之间的相互作用对于干细胞的维持至关重要。本文中，作者发现在自然生长条件下，内源性的胁迫相关信号（ESS）在植物地上组织的干细胞niche中大量表达，并且大多数已知的干细胞特异性和niche特异性基因会响应胁迫信号。通过阻断乙烯信号来干扰干细胞niche中的ESS，会破坏干细胞的维持。EIN3是乙烯信号转导的关键转录因子，能够直接激活干细胞niche中胁迫核心转录因子AGL22的表达，并将ESS信号传递给WUS/CLV网络。本文的结果为ESS信号转导控制干细胞niche提供了一个机制框架，并揭示了植物干细胞在体内是由一个自然的胁迫微环境维持的。