Laboratoire Reproduction et Développement des Plantes, Univ Lyon, ENS de Lyon, UCB Lyon 1, CNRS, INRAE, Inria, Lyon, France.
Department of Stem Cell Biology, Centre for Organismal Studies, Heidelberg University, Heidelberg, Germany.
Elife. 2020 May 7;9:e55832. doi: 10.7554/eLife.55832.
Positional information is essential for coordinating the development of multicellular organisms. In plants, positional information provided by the hormone auxin regulates rhythmic organ production at the shoot apex, but the spatio-temporal dynamics of auxin gradients is unknown. We used quantitative imaging to demonstrate that auxin carries high-definition graded information not only in space but also in time. We show that, during organogenesis, temporal patterns of auxin arise from rhythmic centrifugal waves of high auxin travelling through the tissue faster than growth. We further demonstrate that temporal integration of auxin concentration is required to trigger the auxin-dependent transcription associated with organogenesis. This provides a mechanism to temporally differentiate sites of organ initiation and exemplifies how spatio-temporal positional information can be used to create rhythmicity.
位置信息对于协调多细胞生物的发育至关重要。在植物中，激素生长素提供的位置信息调节着茎尖有节奏的器官产生，但生长素梯度的时空动态尚不清楚。我们使用定量成像技术证明，生长素不仅在空间上，而且在时间上传递高清晰度的分级信息。我们表明，在器官发生过程中，生长素的时间模式源于通过组织快速移动的高生长素的有节奏的离心波，其速度快于生长。我们进一步证明，生长素浓度的时间整合对于触发与器官发生相关的生长素依赖性转录是必需的。这为时间上区分器官起始点提供了一种机制，并例证了时空位置信息如何用于产生节律性。
