Differential growth regulation in plants

植物激素生长素对不对称生长调节具有突出的重要性，最终控制植物结构。然而，植物生长调节知之甚少。到目前为止，系统的分析植物激素串扰细胞生长regulation. There的缺失，我们建议使用根表皮细胞作为一个模型系统，系统地解决生长素调节细胞分裂，伸长和分化事件。根表皮细胞在根毛（毛细胞）和非毛（无毛细胞）细胞中有规律地分布。毛细胞和无毛细胞之间的第一个可见的差异已经在分生组织区域中检测到，其中毛细胞显示出更强烈的细胞质染色，更短的细胞经历更高的细胞分裂速率，以及相对于细胞伸长的空泡化延迟。除了差异生长行为，根表皮细胞可用于超分辨率成像技术，此外，根-土壤界面的形成，根器官大小的确定和向重力生长反应具有突出的发育重要性。因此，毛细胞/无毛细胞特化代表了细胞大小调节的适用模型。我们建议使用表皮根细胞作为一个合适的模型系统来解开生长素依赖的差异生长调节。值得注意的是，根毛信号突变体显示无论是只有毛或只有atrichoblast发展表现出过敏性和耐根生长时，分别用生长素处理。我们将特别关注生长素依赖的液泡生物发生的调节及其在膨压驱动的细胞扩张中的重要性。这种系统的方法，使用遗传学，药理学，转录和定义活细胞成像工具，将提供新的见解植物细胞生长的特定调节。

The phytohormone auxin has outstanding importance for asymmetric growth regulation, ultimately controlling plant architecture. However, plant growth regulation is poorly understood. To date, systematic analysis of phytohormonal crosstalk for cellular growth regulation is missing.Here we propose to use root epidermal cells as a model system to systematically address auxin regulated cellular division, elongation and differentiation events. Root epidermal cells are regularly spaced in root hair (trichoblast) and non-hair (atrichoblast) cells. The first visible differences between tricho- and atrichoblast cells are already detectable in the meristematic region, where trichoblast cells show a more intense cytoplasmic staining, shorter cells that undergo a higher rate of cell division, and a delay in vacuolization relative to cell elongation. Beside the differential growth behavior, root epidermal cells are accessible for super resolution imaging techniques and moreover have outstanding developmental importance for root-soil interface formation, root organ size determination and gravitropic growth responses. Hence, trichoblast/atrichoblast specification represents an applicable model for cell size regulation. We propose to use epidermal root cells as a suitable model system to unravel auxin dependent differential growth regulation. Notably, root hair signaling mutants displaying either only tricho- or only atrichoblast development show hypersensitive and resistant root growth when treated with auxin, respectively. We will particularly focus on the auxin-dependent regulation of vacuolar biogenesis and its importance in turgor driven cell expansion. This systematic approach, using genetic, pharmacological, transcriptom and defined live cell imaging tools, will provide novel insight into plant specific regulation of cellular growth.