Abstract

背景回顾+问题：Wound healing in plant tissues, consisting of rigid cell wall-encapsulated cells, represents a considerable challenge and occurs through largely unknown mechanisms distinct from those in animals. Owing to their inability to migrate, plant cells rely on targeted cell division and expansion to regenerate wounds. Strict coordination of these wound-induced responses is essential to ensure efficient, spatially restricted wound healing. 

技术基础：Single-cell tracking by live imaging allowed us to gain mechanistic insight into the wound perception and coordination of wound responses after laser-based wounding in Arabidopsis root.

结果发现：We revealed a crucial contribution of the collapse of damaged cells in wound perception and detected an auxin increase specific to cells immediately adjacent to the wound. This localized auxin increase balances wound-induced cell expansion and restorative division rates in a dose-dependent manner, leading to tumorous overproliferation when the canonical TIR1 auxin signaling is disrupted. Auxin and wound-induced turgor pressure changes together also spatially define the activation of key components of regeneration, such as the transcription regulator ERF115.

结论：Our observations suggest that the wound signaling involves the sensing of collapse of damaged cells and a local auxin signaling activation to coordinate the downstream transcriptional responses in the immediate wound vicinity.

摘  要

植物组织的创伤自愈，形成由硬质细胞壁包裹着的细胞，代表了植物科学研究领域的一个重要挑战，其潜在的分子调控机制与动物中的自愈机制不同，且在很大程度上都处于未知状态。由于其无法迁移的特性，植物细胞必须依赖于靶向细胞分裂和扩张来再生创伤组织。伤口诱导响应之间的严密协调保证了高效地、组织部位特异性地创伤自愈。本文中，作者通过实时成像进行单细胞追踪，研究了拟南芥根组织中激光烧蚀后的创伤感知以及创伤响应之间的协调。作者发现了受损伤细胞的瓦解对于创伤感知具有非常关键的作用；另外，细胞受损伤之后，其毗邻细胞中立马检测到了生长素的增加。这种局部生长素通过剂量依赖性的方式增强了创伤诱导细胞扩张与恢复性分裂速率之间的平衡，在经典TIR1生长素信号转导被扰乱后导致肿瘤式的过度增殖。生长素和创伤诱导的膨压变化同时作用于局部再生关键组份的激活，比如说转录调控因子ERF115。本研究的发现揭示了植物中创伤信号转导涉及了受损伤细胞瓦解的感知以及局部生长素信号的激活，从而来协调伤口邻近处即时的下游转录响应。

 通讯作者