Cell-specific analysis of plant shade avoidance responses

植物避荫反应的细胞特异性分析

• 批准号: 8315971
• 负责人: Carl Procko
• 金额: $ 4.71万
• 依托单位: SALK INSTITUTE FOR BIOLOGICAL STUDIES
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-05-01 至 2015-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8315971
• 关键词: Affect; Agriculture; Anabolism; Animals; Arabidopsis; Architecture; Auxins; Blood Vessels; Candidate Disease Gene; Cell Nucleus; Cell Separation; Cells; Complex; Defect; Development; Environment; Epidermis; Flowers; Fluorescence-Activated Cell Sorting; Future; Gene Expression; Gene Expression Profile; Gene Targeting; Genes; Genetic Transcription; Genomics; Glean; Growth; Health; Human; Hypocotyl; Individual; Knowledge; Laboratories; Length; Light; Measures; Mediating; Methodology; Mouse-ear Cress; Nuclear; Organ; Organism; Pathway interactions; Phenotype; Plant Growth Regulators; Plant Leaves; Plants; Population; Procedures; Process; RNA Sequences; Role; Seedling; Shapes; Signal Pathway; Signal Transduction; Simulate; Structure of placental cotyledon; Study models; System; T-DNA; Techniques; Technology; Testing; Tissues; Transaminases; Transcript; Transgenic Organisms; cell type; density; developmental plasticity; environmental change; intercellular communication; interest; laser capture microdissection; mutant; novel; plant growth/development; promoter; response; stem; tool

DESCRIPTION (provided by applicant): Being sessile, a plant's development is exquisitely controlled by its environment. In response to impending shade, a plant's architecture undergoes a profound morphological change, including stem elongation and accelerated flowering. This phenotype has consequences in agriculture, where shade avoidance responses in densely grown plants may reduce the growth of harvestable organs. As such, the perturbation of signaling pathways required for shade avoidance may produce crops with better yields. Previous studies of the model plant Arabidopsis thaliana have shown that shade signals because a rapid increase in the synthesis of the phytohormone auxin in leaves. Auxin is subsequently transported to stems to promote elongation growth. Therefore, it is likely that specific cell types have specialized responses to shade. However, the analysis of cell-specific expression changes in the Arabidopsis shoot has been lacking, primarily due to limitations in techniques required to isolate a given cell population. Here, the recently developed INTACT methodology will be used to study gene expression changes in shoot cell types. The leaf and cotyledons sense many light signals, and nuclear transcripts from the three major tissues of these organs, the mesophyll, epidermis and vasculature, will be purified. Using RNA-Sequencing technology, this proposal will test the changes in gene expression in these cells in response to simulated shade. By comparing these changes with that of mutant plants defective for shade-induced auxin biosynthesis, it will be determined if the gene expression changes in a given cell type are in part downstream of auxin signals. Using the information gleaned from this analysis, available T-DNA insertion mutants of potentially interesting cell-specific shade-regulated genes will be tested for defects in shade avoidance phenotypes. Interesting candidate genes would be auxin biosynthesis genes, which may be spatially controlled, or transcriptional regulators, some of which are already known to have a role in the shade avoidance phenotype. The gene's cell-specific role in modulating plant architecture will be assessed by expressing the gene under relevant cell-specific promoters and testing how this affects plant environmental responses. This analysis will place novel and previously identified factors required for shade avoidance into a spatial, cell-type specific context. Ultimately, the spatial perturbation of the genes identified here may generate plants where architectural changes in response to shade are controlled in an organ-specific manner. This may be advantageous in commercial plant species, where shade responses can be spatially tuned to produce maximum yield in a given environment. Furthermore, the proposal seeks to understand how environmental change is transduced at the cellular level to affect an organism's body plan during development. PUBLIC HEALTH RELEVANCE: A plant optimizes its organ shape and size to its local environment, providing an excellent system for the study of developmental plasticity in response to environmental challenges. This proposal seeks to better understand the spatial and cell-specific changes that occur in plants to generate organs of different shapes in response to light, the perturbation of which may be useful to generate commercial crops with higher yields. In addition, these studies may be suggestive of common evolutionary themes of how different cell types in both plants and animals are coordinated to produce complex organs, and how these processes can go awry to affect human health.

描述（申请人提供）：无柄，植物的发展是由它的环境精致控制。为了应对即将到来的阴影，植物的结构经历了深刻的形态变化，包括茎伸长和加速开花。这种表型在农业中具有后果，其中密集生长的植物中的避荫反应可能减少可收获器官的生长。因此，对避荫所需的信号通路的干扰可能会产生具有更好产量的作物。先前对模式植物拟南芥的研究表明，遮荫信号是因为叶片中植物激素生长素的合成迅速增加。生长素随后被运输到茎以促进伸长生长。因此，很可能特定的细胞类型对阴影有专门的反应。然而，在拟南芥芽中的细胞特异性表达变化的分析一直缺乏，主要是由于在分离给定的细胞群体所需的技术的限制。在这里，最近开发的INTACT方法将用于研究芽细胞类型的基因表达变化。叶和子叶感受许多光信号，并且来自这些器官的三个主要组织（叶肉、表皮和脉管系统）的核转录物将被纯化。利用RNA测序技术，该提案将测试这些细胞中基因表达的变化，以响应模拟阴影。通过将这些变化与遮荫诱导的生长素生物合成缺陷的突变体植物的变化进行比较，将确定给定细胞类型中的基因表达变化是否部分地在生长素信号的下游。使用从该分析中收集的信息，将测试潜在感兴趣的细胞特异性遮荫调节基因的可用T-DNA插入突变体在避荫表型中的缺陷。感兴趣的候选基因将是生长素生物合成基因，这可能是空间控制，或转录调控因子，其中一些已经知道有一个避荫表型的作用。该基因在调节植物结构中的细胞特异性作用将通过在相关细胞特异性启动子下表达该基因并测试其如何影响植物环境响应来评估。这种分析将把新的和以前确定的因素所需的避荫到一个空间，细胞类型的特定背景。最终，在这里确定的基因的空间扰动可能会产生植物，其中响应于遮荫的结构变化以器官特异性的方式控制。这在商业植物物种中可能是有利的，其中可以在空间上调节阴影响应以在给定环境中产生最大产量。此外，该提案旨在了解环境变化如何在细胞水平上转导，以影响生物体在发育过程中的身体计划。 公共卫生关系：植物优化其器官的形状和大小，以适应当地的环境，为研究发育可塑性提供了一个很好的系统。该提案旨在更好地理解植物中发生的空间和细胞特异性变化，以响应光产生不同形状的器官，其扰动可能有助于产生具有更高产量的商业作物。此外，这些研究可能暗示了植物和动物中不同细胞类型如何协调以产生复杂器官的共同进化主题，以及这些过程如何出错以影响人类健康。