Collaborative Research: Hormonal control of stamen filament growth

合作研究：雄蕊丝生长的激素控制

• 批准号: 2343702
• 负责人: Bastiaan Bargmann
• 金额: $ 29万
• 依托单位: Virginia Polytechnic Institute and State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2024
• 资助国家: 美国
• 起止时间: 2024-02-15 至 2027-01-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2343702&HistoricalAwards=false
• 关键词: Collaborative; Research; Hormonal; control; stamen

In both plants and animals, many organs undergo spurts of rapid growth as they develop. Many flower organs grow very quickly for a brief period as flowers open. For successful reproduction, such growth must be coordinated so as to place male and female organs appropriately for pollination, and pollen release needs to occur at an optimal time. This project is to study how plant hormones stimulate rapid growth in stamens, the male flower organs that produce pollen. In many self-pollinating plants, stamen filaments elongate as flowers open to place pollen-bearing anthers near the female stigma. The timing and extent of filament growth thus determines the efficiency of fertilization and seed production, and is important for crop breeding and yield. The project will examine cellular and molecular events during stamen filament elongation in a model plant, to reveal in detail how stamens grow quickly without buckling, how hormones control this growth, and how filament growth is coordinated with pollen release. Genetic tools generated in the work may enable targeted modification of growth in flower organs, for example to modulate the location and timing of pollen release in crop plants. The mechanisms discovered will also be relevant to modulating growth in other organs such as leaves or fruits. Undergraduate students will be introduced to methods of scientific inquiry through carrying out research projects both in courses and in the research labs. Public outreach through museums and campus events will include information on plant reproduction. The project is to study how hormone response pathways control very fast but transient stamen filament growth in the model plant Arabidopsis thaliana. Two auxin response transcription factors, ARF6 and ARF8, mediate growth responses to the hormone auxin, and stimulate stamen filament elongation just before flowers open. ARF6 and ARF8 also stimulate production of another hormone, jasmonate, which further amplifies filament growth rate, and also promotes differentiation needed for anther dehiscence (pollen release). Time-lapse confocal microscopy, single-nucleus RNA-Seq, and fluorescent reporter genes for selected vascular cell types will be used to reconstruct three-dimensional cellular anatomy, growth, and differentiation in rapidly growing stamen filaments. Comparisons of wild type and mutants with decreased or increased hormone responses and filament growth will provide insight into how the hormones act. Biophysical, hormonal, and genetic manipulations, together with jasmonate pathway reporter genes, will probe mechanisms that couple filament growth with the contemporaneous burst of jasmonate production needed for anther dehiscence. Yeast and plant protoplast gene expression systems will be used to identify mutant forms of ARF6 and ARF8 that can activate transcription independently of auxin regulation. Such auxin-independent mutations will then be engineered into Arabidopsis plants to reveal the role of auxin response in flower maturation and other processes.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.

在植物和动物中，许多器官在发育过程中都经历了快速生长的过程。 许多花的器官在花开放的短暂时期内生长得非常快。 为了成功繁殖，这种生长必须协调，以便将雄性和雌性器官适当地放置用于授粉，并且花粉释放需要在最佳时间发生。 这个项目是研究植物激素如何刺激雄蕊的快速生长，雄蕊是产生花粉的雄花器官。 在许多自花授粉的植物中，雄蕊花丝随着花朵的开放而伸长，将带有花粉的花药放置在雌蕊柱头附近。 因此，花丝生长的时间和程度决定了施肥和种子生产的效率，对作物育种和产量很重要。 该项目将研究模型植物中雄蕊丝伸长过程中的细胞和分子事件，以详细揭示雄蕊如何快速生长而不弯曲，激素如何控制这种生长，以及花丝生长如何与花粉释放协调。 在这项工作中产生的遗传工具可以有针对性地改变花器官的生长，例如调节作物花粉释放的位置和时间。 发现的机制也将与调节其他器官（如叶子或果实）的生长有关。 本科生将通过在课程和研究实验室开展研究项目来介绍科学探究的方法。 通过博物馆和校园活动进行的公众宣传将包括关于植物繁殖的信息。该项目是研究激素反应途径如何控制模式植物拟南芥中非常快速但短暂的雄蕊丝生长。 两个生长素反应转录因子，ARF 6和ARF 8，介导对激素生长素的生长反应，并在花开放前刺激雄蕊丝伸长。 ARF 6和ARF 8还刺激另一种激素茉莉酸的产生，茉莉酸进一步放大花丝生长速率，并促进花药开裂（花粉释放）所需的分化。 延时共聚焦显微镜，单核RNA-Seq，和荧光报告基因选定的维管细胞类型将用于重建三维细胞解剖，生长和分化快速生长的雄蕊丝。 野生型和突变体的激素反应和细丝生长的减少或增加的比较将提供对激素如何作用的洞察。 生物物理，激素和遗传操作，连同茉莉酸途径报告基因，将探测机制，耦合丝生长与同期爆发的茉莉酸生产所需的花药开裂。 酵母和植物原生质体基因表达系统将被用来鉴定ARF 6和ARF 8的突变形式，这些突变形式可以独立于生长素调节激活转录。 这种不依赖生长素的突变将被工程化到拟南芥植物中，以揭示生长素反应在花成熟和其他过程中的作用。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。