The Arabidopsis shoot apical meristem tool kit: a unifying set of cell type specific driver and effector lines for functional analysis of cellular identities in the SAM

遗传和分子研究已经在拟南芥中发现了大量的基因，这些基因是茎顶端分生组织(SAM)功能的重要组成部分，并简化了我们对分生组织组织的概念，包括分层和分区。利用DORNRÖschen类转录因子，我们发现了一个新的基因功能，它标志着侧器创始细胞，在SAM外围表达先于生长素最大值。该项目旨在将特征良好的特定于SAM的启动子结合到一组驱动器线中，以稳定(LhG4)或诱导(LhG4GR)寻址SAM或初始原基中的不同细胞类型或隔室。这些驱动系的特征是结合不同的荧光团报告，可以同时分析现有的稳定启动子：：GFP系；因此，直接的结果将是比较的启动子活性及其在SAM中的动态。然而，真正的驱动系可以用来在芽尖预测地表达转基因，并可以自由地与多种效应器结构相结合。由此产生的工具箱将大大改进萌芽顶端的分析方法，并提供一个新的社区资源，用于访问SAM的监管网络。在新的技术发展方面，我们将测试细胞类型特异性的Cre/loxP依赖的GUS报告蛋白的激活或白喉A毒素细胞死亡报告的诱导性细胞消融是否可以识别SAM内的克隆谱系，并阐明个别细胞类型的贡献。

Genetic and molecular studies have identified numerous genes in Arabidopsis thaliana, which contribute essential components for shoot apical meristem (SAM) function, and have streamlined our conceptual view on meristem organisation, with respect to layering and zonation. With the DORNRÖSCHEN-LIKE transcription factor, we have identified a novel gene function, that marks lateral organ founder cells and expression precedes auxin maxima at the SAM periphery. This project aims to combine well-characterised, SAM-specific promoters into one set of driver lines that stably (LhG4) or inducibly (LhG4GR) address different cell types or compartments within the SAM or incipient primordia. These driver lines are characterised in combinations with different fluorophore reporters, which can concomitantly be analysed with existing stable promoter::GFP lines; immediate results will therefore be comparative promoter activities and their dynamics within the SAM. However, bona fide driver lines can then be used to predictably express transgenes in the shoot apex and be freely combined with many kinds of effector constructs. The resulting toolbox will substantially improve the repertoire of analytic methods in the shoot apex and provide a new community resource with which to access regulatory networks in the SAM. With respect to new technology developments, we will test whether cell type-specific CRE/loxP-dependent activation of the GUS reporter or inducible cell ablation with the diphtheria A toxin cell death reporter can identify clonal lineages within the SAM and elucidate on the contribution of individual cell types.