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，这些基因为茎尖分生组织（SAM）功能提供了重要组成部分，并简化了我们对分生组织组织（分层和分区）的概念看法。通过 DORNRÖSCHEN-LIKE 转录因子，我们鉴定了一种新的基因功能，该功能标记侧向器官创始细胞，并在 SAM 外围的生长素最大值之前表达。该项目旨在将特征明确的 SAM 特异性启动子组合成一组驱动系，稳定地 (LhG4) 或可诱导地 (LhG4GR) 处理 SAM 或初期原基内的不同细胞类型或区室。这些驱动线的特点是与不同的荧光团报告基因组合，可以与现有的稳定启动子::GFP线同时进行分析；因此，直接结果将是比较启动子活动及其在 SAM 内的动态。然而，真正的驱动系可以用于在茎尖中可预测地表达转基因，并与多种效应子构建体自由组合。由此产生的工具箱将大大改进茎尖的分析方法库，并提供新的社区资源来访问 SAM 中的监管网络。关于新技术的发展，我们将测试 GUS 报告基因的细胞类型特异性 CRE/loxP 依赖性激活或白喉 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.