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许多基因，这些基因对茎尖分生组织（SAM）的功能起重要作用，并简化了我们对分生组织的分层和分带的概念观点。通过DORNRÖSCHEN-LIKE转录因子，我们发现了一种新的基因功能，它标志着侧壁器官建立细胞，并在SAM周围的生长素最大化之前表达。该项目旨在将表征良好的SAM特异性启动子结合到一组驱动系中，该驱动系稳定地（LhG4）或诱导地（LhG4GR）处理SAM或早期原基中的不同细胞类型或区室。这些驱动系与不同的荧光团报告基因组合，可以同时与现有的稳定启动子GFP系进行分析；因此，直接结果将是比较启动子活动及其在SAM中的动态。然而，真正的驱动系可以用来在茎尖上表达可预测的转基因，并与多种效应构建体自由结合。由此产生的工具箱将大大改善在茎尖的分析方法的曲目，并提供一个新的社区资源，与进入管理网络在SAM。关于新技术的发展，我们将测试细胞类型特异性CRE/ loxp依赖性GUS报告基因的激活或白喉A毒素细胞死亡报告基因的诱导细胞消融是否可以识别SAM内的克隆谱系，并阐明单个细胞类型的贡献。

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.