Wounding-induced changes in cellular pressure and localized auxin signalling spatially coordinate restorative divisions in roots
Wounding-induced changes in cellular pressure and localized auxin signalling spatially coordinate restorative divisions in roots
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DOI：
10.1073/pnas.2003346117
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发表时间：
2020-06-30
影响因子：
11.1
通讯作者：
Friml, Jiri
中科院分区：
文献类型：
--
作者：
Hoermayer, Lukas;Montesinos, Juan Carlos;Friml, Jiri
由刚性细胞壁包裹的细胞组成的植物组织中的伤口愈合代表了相当大的挑战，并且通过与动物中的机制不同的很大程度上未知的机制发生。由于它们不能迁移，植物细胞依赖于靶向细胞分裂和扩增来再生伤口。严格协调这些伤口诱导的反应对于确保有效的、空间受限的伤口愈合至关重要。通过活体成像的单细胞跟踪使我们能够深入了解拟南芥根激光损伤后的伤口感知和伤口反应的协调机制。我们揭示了损伤细胞的崩溃在伤口感知中的重要作用，并检测到紧邻伤口的细胞特异性生长素增加。这种局部生长素增加以剂量依赖性方式平衡伤口诱导的细胞扩增和恢复性分裂速率，当典型的TIR 1生长素信号传导被破坏时导致肿瘤过度增殖。生长素和伤口诱导的膨压变化一起也在空间上定义了再生的关键成分，如转录调节因子ERF115的激活。我们的观察结果表明，伤口信号涉及受损细胞的崩溃和局部生长素信号激活，以协调下游的转录反应，在伤口附近的传感。
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. 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. 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. 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.