Exploring the logic of transcriptional circuitry during DNA damage in plants at the single cell level

维持基因组的完整性，特别是在植物的整个生命周期中产生新器官和组织的分生组织中，对植物的生存和生长至关重要。然而，不同的细胞，即使在分生组织中，对DNA损伤的反应也非常不同。已经鉴定了几种控制植物DNA损伤反应（DDR）的转录因子。然而，它们如何以及以何种顺序在不同的细胞类型中诱导不同的反应仍然是一个悬而未决的问题。连续水平的响应的协调激活，以及不同细胞类型中细胞分裂和细胞死亡的差异控制，对于响应DNA损伤而保持分生组织功能是必不可少的。在这个项目中，我们建议在空间和时间上解决与根分生组织中的DDR相关的调控网络。根分生组织通常最先暴露于环境中的潜在有毒物质，并且对于根的生长也是必不可少的，因此对于整个植物也是如此。通过结合最新的基因组技术（snRNAseq和snATACseq），细胞生物学（实时成像）和生物化学（邻近标记），我们将以细胞特异性方式重建DDR中涉及的调控网络。该模型将通过反向遗传学和分子生物学（ChIP）方法进行验证。除了时空分辨率的DDR，这是必不可少的了解分生组织的功能是如何保存在应对压力，这些综合方法的实施将铺平道路，适用于其他生理环境，如热应激或干旱的类似研究，从而解决与植物生长在气候变化的背景下的主要挑战。

The maintenance of genome integrity, especially in meristems that generate new organs and tissues throughout the life of the plant, is essential for the survival and growth of plants. However, different cells, even within a meristems, react very differently towards DNA damage. Several transcription factors controlling the DNA damage response (DDR) in plants have been identified. However, how and in what order they act to induce different responses in different cell types remains an open question. The coordinated activation of successive levels of response, and the differential control of cell division and cell death in different cell types, are essential to preserve meristematic function in response to DNA damage. In this project, we propose to spatially and temporally resolve the regulatory network associated with DDR in the root meristem. The root meristem is generally the first to be exposed to potential toxic substances in the environment, and is also essential for root growth, and thus for the whole plant. By combining the most recent genomic techniques (snRNAseq and snATACseq), cell biology (live-imaging) and biochemistry (proximity labelling), we will reconstruct the regulatory networks involved in the DDR in a cell-specific manner. This model will be validated by reverse genetics and molecular biology (ChIP) approaches. Beyond the spatio-temporal resolution of the DDR, which is essential to understand how meristematic function is preserved in response to stress, the implementation of these integrative approaches will pave the way for similar studies applied to other physiological contexts such as heat stress or drought, thus addressing the major challenges associated with plant growth in the context of climate change.