背景回顾：Plant cells in damaged tissue can be reprogrammed to acquire pluripotency and induce callus formation. 

提出问题：However, in the aboveground organs of many species, somatic cells that are distal to the wound site become less sensitive to auxin-induced callus formation, suggesting the existence of repressive regulatory mechanisms that are largely unknown. 

主要发现：Here, we reveal that submergence-induced ethylene signals promote callus formation by releasing post-transcriptional silencing of auxin receptor transcripts in non-wounded regions. 

结果1-水淹促进非创伤处的愈伤形成：We determined that short-term submergence of intact seedlings induces auxin-mediated cell dedifferentiation across the entirety of Arabidopsis (Arabidopsis thaliana) explants. 

结果2-乙烯作用于愈伤形成：The constitutive triple response 1-1 (ctr1-1) mutation induced callus formation in explants without submergence, suggesting that ethylene facilitates cell dedifferentiation.  

结果3-乙烯信号转录后调控生长素受体基因：Furthermore, we show that ETHYLENE INSENSITIVE 2 (EIN2) post-transcriptionally regulates the abundance of transcripts for auxin receptor genes by facilitating microRNA393 (miR393) degradation. 

结果4-愈伤的再生能力：Submergence-induced calli in non-wounded regions were suitable for shoot regeneration, similar to those near the wound site.

结果5-该机制的保守性：We also observed submergence-promoted callus formation in Chinese cabbage (Brassica rapa), indicating that our findings may also be applicable in other species. 

结论：Our study identifies previously unknown regulatory mechanisms by which ethylene promotes cell dedifferentiation and provides a new approach for boosting callus induction efficiency in shoot explants.

在损伤组织中的植物细胞可以经过重编程后，获得多能性，从而诱导愈伤组织的形成。但是，在许多植物地上器官中那些远离创伤的体细胞，对于生长素诱导的愈伤形成会更加不敏感，说明存在某种未知的抑制调控机制在发挥作用。本文中，作者发现水淹诱导的乙烯信号会通过释放生长素受体转录本的转录后沉默，在非创伤处促进愈伤组织的形成。作者发现通过对完整幼苗的短期水淹处理，能够诱导整个拟南芥外植体上经生长素介导的细胞脱分化。乙烯信号通路负调控子CRT1基因的突变（ctr1-1突变体）会导致突变体植株在不经过水淹的情况下，直接可诱导愈伤，说明乙烯促进了细胞脱分化。此外，作者发现乙烯信号通路正调控子EIN2能够通过促进miR393的降解，在转录后水平上调节生长素受体基因的转录本丰度。非创伤器官处由水淹诱导的愈伤能够进行芽再生，与创伤处诱导的愈伤具有类似的能力。作者还发现，水淹促进的愈伤形成在大白菜中同样存在，说明本文所揭示的调控机制在其他物种中也适用。本文的研究鉴定到了一个乙烯促进细胞脱分化的新的调控机制，为提高以植物地上组织为外植体的愈伤诱导效率提供了新的方法。