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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.

被子植物的非凡多样性是由它们的花促进的，这促进了异交。异交保持了遗传变异，对杂交种子生产至关重要。然而，作物生产往往是通过自花授粉和异花授粉的结合来促进的。因此，植物育种者产生优先自花授粉或异花授粉的植物的能力是非常有用的，但目前仅限于少数作物。两种相关的作物，莴苣和向日葵，具有非常相似的花解剖学。尽管有这些相似之处，莴苣是完全自花授粉，而向日葵则依赖于昆虫的异花授粉。以生菜和向日葵为模型，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，以产生生菜和向日葵中这些不同的生殖策略。具体来说，研究人员使用基因组，生理和定量遗传方法来更好地了解后期花发育的精确时间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找到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和观察到的野生和管理传粉者种群的下降，更好地了解植物交配策略及其受环境因素调节的特征是未来农艺学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了跨学科的培训，使他们能够在高度融合的研究时代茁壮成长。先雄后雌是一种生殖策略，在包括栽培向日葵在内的许多植物物种中促进异交。初步数据表明，雄性先熟期受生物钟和环境的调节。在莴苣，这几乎是完全自花授粉，小花形态类似于栽培向日葵，但男性和女性阶段同时发生。这两种作物，向日葵和生菜将被用作模型，以定义环境和内部线索如何指导花器官生长，以促进异交或自花授粉。比较转录组学研究被用来确定控制后期花发育时间的途径。该团队使用定量基因组研究来揭示影响小花成熟的遗传变异的潜在结构，并识别其对自花授粉和异花授粉的影响。开放领域和传粉笼的研究被用来评估的重要性，晚花发育（开花期）相对于其他花卉性状的生殖策略的异交与自交。这些研究突出了在次优传粉者活动下提高产量的目标，并可能促进对传粉者更具吸引力的近交系的开发，从而可能导致杂交种子生产者大幅节省成本。高中生，本科生和社区志愿者在教室，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。本科实习生是从那些将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。这些努力也为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。