Auxin-Independent NAC Pathway Acts in Response to Explant-Specific Wounding and Promotes Root Tip Emergence during de Novo Root Organogenesis in Arabidopsis
Auxin-Independent NAC Pathway Acts in Response to Explant-Specific Wounding and Promotes Root Tip Emergence during de Novo Root Organogenesis in Arabidopsis
复制标题
不依赖生长素的 NAC 途径响应外植体特异性损伤，并在拟南芥从头器官发生过程中促进根尖出现
DOI：
10.1104/pp.15.01733
复制
发表时间：
2016-04-01
期刊：
影响因子：
7.4
通讯作者：
Xu, Lin
中科院分区：
文献类型：
--
作者：
Chen, Xiaodong;Cheng, Jingfei;Xu, Lin
植物具有强大的再生能力，使它们能够从损害中恢复并在自然界中生存。从头器官发生是植物再生的一种类型，其中不定根和芽是从受伤和离体器官产生的。通过研究拟南芥（Arabidopsis thaliana）叶外植体的从头根器官发生，我们以前认为，受伤是第一个事件，提供信号，触发整个再生过程。然而，我们对创伤在再生中的作用的认识仍然有限。在这项研究中，我们表明，创伤不仅触发生长素介导的再生感受态细胞的命运转变，但也诱导NAC途径的根尖出现。NAC1转录因子基因特异性地表达响应于叶外植体中的创伤，但在源植物的创伤叶残留物中不表达。抑制NAC1途径严重影响不定根尖的出现。然而，NAC1途径独立于生长素介导的细胞命运转变发挥作用，并调节CEP基因的表达，CEP基因编码的蛋白质可能在细胞壁中的伸展蛋白的降解中发挥作用。总体而言，我们的研究结果表明，创伤有多种角色从头根器官发生和NAC 1作为一个下游分支在调节细胞环境的器官出现。
Plants have powerful regenerative abilities that allow them to recover from damage and survive in nature. De novo organogenesis is one type of plant regeneration in which adventitious roots and shoots are produced from wounded and detached organs. By studying de novo root organogenesis using leaf explants of Arabidopsis (Arabidopsis thaliana), we previously suggested that wounding is the first event that provides signals to trigger the whole regenerative process. However, our knowledge of the role of wounding in regeneration remains limited. In this study, we show that wounding not only triggers the auxin-mediated fate transition of regeneration-competent cells, but also induces the NAC pathway for root tip emergence. The NAC1 transcription factor gene was specifically expressed in response to wounding in the leaf explant, but not in the wounded leaf residue of the source plant. Inhibition of the NAC1 pathway severely affected the emergence of adventitious root tips. However, the NAC1 pathway functioned independently of auxin-mediated cell fate transition and regulates expression of CEP genes, which encode proteins that might have a role in degradation of extensin proteins in the cell wall. Overall, our results suggest that wounding has multiple roles in de novo root organogenesis and that NAC1 acts as one downstream branch in regulating the cellular environment for organ emergence.