Transcriptional control of growth regulatory modules by AIL transcription factors

AIL转录因子对生长调节模块的转录控制

• 批准号: 2211715
• 负责人: Beth Krizek
• 金额: $ 54.92万
• 依托单位: University of South Carolina at Columbia
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-01 至 2026-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2211715&HistoricalAwards=false
• 关键词: Transcriptional; control; growth; regulatory; modules

The size of plant organs depends on both the number and size of the constituent cells. Growth within developing organs consists of an early phase in which there is an increase in cell number followed by a later phase in which cells expand in size. Pathways that regulate the rate of cell division or expansion, or the duration of either phase of growth have been identified. However, the regulation of these pathways and how output from these different pathways is integrated to control the final size of a plant organ is not well understood. The work proposed here will investigate regulation of growth pathways in the model plant Arabidopsis thaliana. Understanding the mechanisms regulating the growth of leaves and flowers can have important economic benefits in increasing plant yield and biomass. Larger leaves in leaf vegetable crops and larger flowers and the products they give rise to (fruits, seeds, and grains) can contribute to increased agricultural production needed to feed a growing world population. In addition, the project aims to broaden participation in science by developing a molecular biology lab skills workshop that will be offered to first generation and underrepresented students in their first semester of college. The project will also involve a local K-12 teacher for a summer research experience as part of the South Carolina Research Experience for Teachers (RET) program. A key promoter of organ growth in plants is the transcription factor AINTEGUMENTA (ANT). ANT mutants produce smaller leaves and flowers while overexpression of ANT results in larger leaves and flowers. ChIP-Seq studies show that ANT and the related transcription factor AINTEGUMENTA-LIKE 6/ PLETHORA3 (AIL6/PLT3) are bound to a number of different growth genes in developing floral primordia. This project will test the hypothesis that ANT and AIL6 directly regulate expression of genes from several different growth regulatory modules and that feedback among these different modules integrates growth information to control final organ size. The roles of ANT and AIL6 in regulating the expression of six genes from the miR396/GRF-GIF, DA1/BB, and KLU growth modules, which control the duration of the cell proliferation phase of growth, will be investigated. RT-qPCR, in situ hybridization, promoter:GUS reporters, and laser capture microdissection will be used to characterize the expression levels and patterns of these growth genes in response to changes in ANT and AIL6 activity. Cis-regulatory elements bound by ANT and AIL6 will be determined using electrophoretic mobility shift assays. Mutated promoter:GUS reporters, CRISPR-Cas genome editing, and ChIP-qPCR assays will probe the importance of these identified cis-elements in vivo. In addition, the project will investigate whether reciprocal cross-regulation occurs between ANT/AIL6 and these other growth modules.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

植物器官的大小取决于组成细胞的数量和大小。发育中的器官内的生长由一个早期阶段组成，在该阶段中，细胞数的增加，然后是一个后期，其中细胞的大小扩大。已经确定了调节细胞分裂速率或扩张率的途径，或者已经确定了任一期生长阶段的持续时间。但是，对这些途径的调节以及如何整合来自这些不同途径的输出以控制植物器官的最终大小。这里提出的工作将调查模型植物拟南芥中生长途径的调节。了解调节叶子和花朵生长的机制可以在增加植物产量和生物量方面具有重要的经济利益。叶植物作物和较大的花朵中的较大叶子及其产生的产品（水果，种子和谷物）可以促进养活不断增长的世界人口所需的农业生产。此外，该项目旨在通过开发分子生物学实验室技能研讨会来扩大对科学的参与，该讲习班将在大学的第一学期中提供给第一代和代表性不足的学生。作为南卡罗来纳州教师研究经验（RET）计划的一部分，该项目还将涉及当地的K-12老师进行夏季研究经验。植物器官生长的关键启动子是转录因子Aintegumenta（ANT）。蚂蚁突变体产生较小的叶子和花，而蚂蚁过表达会导致较大的叶子和花朵。 CHIP-Seq研究表明，在发展花卉原始基原始基因中，ANT和相关转录因子类似于Aintegumenta样6/ Plothora3（AIL6/ PLT3）与许多不同的生长基因结合。该项目将检验以下假设：ANT和AIL6直接调节来自几个不同生长调节模块的基因表达，并且这些不同模块之间的反馈会整合生长信息以控制最终器官的大小。将研究蚂蚁和AIL6在调节MiR396/GRF-GIF，DA1/BB和KLU生长模块中调节六个基因表达的作用，这些模块控制了生长细胞增殖阶段的持续时间。 RT-QPCR，原位杂交，启动子：GUS记者和激光捕获显微解剖将用于表征这些生长基因的表达水平和模式，以响应ANT和AIL6活性的变化。由ANT和AIL6结合的顺式调节元素将使用电泳迁移率分析确定。突变的启动子：GUS记者，CRISPR-CAS基因组编辑和CHIP-QPCR分析将探测这些确定的在体内这些鉴定的元素的重要性。此外，该项目还将调查ANT/AIL6和这些其他增长模块之间是否发生相互交叉调节。该奖项反映了NSF的法定任务，并且使用基金会的知识分子优点和更广泛的影响审查标准，被认为值得通过评估来支持。