RESEARCH-PGR: Investigating how internal and external cues coordinate floral organ development and the consequences for plant reproduction

研究-PGR：研究内部和外部线索如何协调花器官发育以及对植物繁殖的影响

基本信息

批准号：
1759942
负责人：
Stacey Harmer
金额：
$ 272.02万
依托单位：
University of California-Davis
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
2018
资助国家：
美国
起止时间：
2018-10-01 至 2024-09-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1759942&HistoricalAwards=false
关键词：
RESEARCH PGR Investigating how internal

项目摘要

The extraordinary diversity of angiosperms is facilitated by their flowers, which promote outcrossing. Outcrossing maintains genetic variation and is essential for hybrid seed production. Crop production however is often facilitated by a combination of self- and cross-pollination. Thus, the ability of plant breeders to generate plants that preferentially self- or cross-pollinate is extremely useful, but currently limited to a small number of crops. Two related crops, lettuce and sunflower, have very similar floral anatomy. Despite these similarities, lettuce is exclusively self-pollinating, while sunflower depends upon cross-pollination by insects. Using lettuce and sunflowers as models, a diverse team of researcher (UC Davis: PI Harmer; UC Berkeley: co-PI Blackman; Iowa State: co-PI Barb) investigate how internal and external factors interact to generate these distinct reproductive strategies in lettuce and sunflower. Specifically, the investigators use genomic, physiological, and quantitative genetic approaches to better understand how the precise timing of late stage floral development promotes self- or cross-pollination. A better understanding of the regulation of these processes is likely to lead to new approaches to modify the frequency of self- and cross-pollination in crop species, providing important new tools for breeders. Given the anticipated challenges of future climates and observed declines in both wild and managed pollinator populations, a better understanding of the traits underlying plant mating strategies and their modulation by environmental factors is key to future agronomic improvements and global food security. The proposed research also provides interdisciplinary training for the next generation of scientists to thrive in an era of highly integrative research. Protandry, the condition in which a single flower is first male and then female, is a reproductive strategy that promotes out-crossing in many plant species including cultivated sunflower. Preliminary data has shown that protandry is regulated both by the circadian clock and the environment. In lettuce, which is almost entirely self-pollinating, floret morphology is similar to cultivated sunflower, but the male and female phases occur simultaneously. These two crops, sunflower and lettuce will be used as models to define how environmental and internal cues direct floral organ growth to promote out-crossing or self-pollination. Comparative transcriptomic studies are used to identify pathways controlling the timing of late-stage floral development. The team uses quantitative genomic studies to uncover the underlying architecture of the genetic variation that affects floret maturation and discern its impact on self- and cross-pollination. Open field and pollinator cage studies are used to assess the importance of the timing of late floral development (anthesis) relative to other floral traits in the reproductive strategies of out-crossing versus selfing. These studies highlight targets for improving yield under suboptimal pollinator activity and may facilitate development of inbred lines that are more attractive to pollinators, potentially leading to substantial cost savings by hybrid seed producers. High school students, undergraduates, and community volunteers contribute to discovery-based research in the classroom, lab, field, and at the UC Botanical Garden. Undergraduate interns are recruited from programs that connect underrepresented groups in STEM fields with researchers. These efforts also provide excellent teaching opportunities for postdoctoral scholars and graduate students supported by the project.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.

被子植物非凡的多样性是由它们的花促进的，花促进了异型杂交。异型杂交可维持遗传变异，对于杂交种子生产至关重要。然而，自花授粉和异花授粉的结合常常促进作物生产。因此，植物育种者培育优先自花授粉或异花授粉植物的能力非常有用，但目前仅限于少数作物。两种相关作物，生菜和向日葵，具有非常相似的花卉解剖结构。尽管有这些相似之处，生菜完全是自花授粉的，而向日葵则依赖于昆虫的异花授粉。使用生菜和向日葵作为模型，一个多元化的研究团队（加州大学戴维斯分校：PI Harmer；加州大学伯克利分校：co-PI Blackman；爱荷华州：co-PI Barb）研究内部和外部因素如何相互作用以在生菜中产生这些不同的繁殖策略和向日葵。具体来说，研究人员使用基因组、生理学和定量遗传学方法来更好地了解花卉发育后期的精确时机如何促进自花授粉或异花授粉。更好地了解这些过程的调节可能会带来改变作物物种自花授粉和异花授粉频率的新方法，为育种者提供重要的新工具。考虑到未来气候的预期挑战以及观察到的野生和管理授粉媒介数量的下降，更好地了解植物交配策略的特征及其受环境因素的调节是未来农艺改进和全球粮食安全的关键。拟议的研究还为下一代科学家提供跨学科培训，使其在高度综合研究的时代蓬勃发展。先熟性是指一朵花首先是雄性，然后是雌性的情况，是一种促进包括栽培向日葵在内的许多植物物种异型杂交的繁殖策略。初步数据表明，早熟受到生物钟和环境的调节。在几乎完全自花授粉的生菜中，小花形态与栽培向日葵相似，但雄性阶段和雌性阶段同时发生。向日葵和生菜这两种作物将被用作模型来定义环境和内部线索如何指导花器官生长以促进异型杂交或自花授粉。比较转录组学研究用于确定控制后期花发育时间的途径。该团队利用定量基因组研究来揭示影响小花成熟的遗传变异的基本结构，并辨别其对自花授粉和异花授粉的影响。开放田地和传粉媒介笼研究用于评估晚花发育（开花）时间相对于异交与自交繁殖策略中其他花性状的重要性。这些研究强调了在授粉媒介活动不佳的情况下提高产量的目标，并可能促进对授粉媒介更具吸引力的自交系的开发，从而可能导致杂交种子生产者节省大量成本。高中生、本科生和社区志愿者在课堂、实验室、现场和加州大学植物园为基于发现的研究做出贡献。本科实习生是从将 STEM 领域代表性不足的群体与研究人员联系起来的项目中招募的。这些努力还为该项目支持的博士后学者和研究生提供了极好的教学机会。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。