BRC-BIO: The transcriptomics of environmentally-controlled differentiation into male or female in plants

植物通过雄性和雌性功能繁殖，就像动物一样。然而，与动物不同的是，大多数植物（约90%）在一个个体中联合收割机雄性和雌性功能。尽管只有不到10%的植物物种有单独的雄性和雌性，但这种植物交配系统在绿色植物的历史中反复进化，并提供了了解其进化的机会。此外，许多经济上重要的作物具有单独的雄性和雌性，并且通常雄性或雌性比另一个更有价值（例如，雌冬青，雄银杏），它们在成熟前很难区分。在其他情况下，保持男性和女性分开和稳定（例如，女性大麻，女性啤酒花）是必要的，以保持产品的质量。尽管植物生物学的这一方面在经济上很重要，但我们对决定植物中这种表达的因素知之甚少。这个项目将研究一组特殊的植物，它们表现出单独的雄性和雌性-那些环境控制雄性或雌性功能表达的植物。 决定雄花或雌花类型的染色体在植物和物种中是罕见的，在这些植物和物种中，环境起着很大的作用，它们能够表达雄花或雌花，并且在它们的生活中从一种变成另一种。基因表达的变化是最有可能的机制控制这种表型在这些物种中，因此，本研究探讨基因表达和花发育的枫树，并与其他植物物种与不同的植物交配系统之间的关系进行比较。更多地了解基因表达如何与雄花和雌花的表达相关，将有助于在面对气候变化时做出更经济的决策和种群稳定计划。该项目还涉及以课程为基础的本科生研究经验的发展，包括现代遗传技术和分析的领域元素和培训。历史上，决定生物体中男性与女性功能的几种机制被分类为：遗传、社会、温度依赖和环境。这种划分导致了对具有可疑环境决定的物种的主要基于生态学的研究，并加强了遗传学和环境之间的错误二分法。 该项目调查了转录组学基础的环境为基础的可塑性在花的功能，并寻求以下问题的答案。1.与花型表达相关的基因表达的数量和种类是否存在差异？2.花发育过程中转录组的变化程度如何？3.与其他物种相比，具有这种可塑性的物种的转录谱有多相似？它更像是那些表现出二聚体或单聚体的人吗？通过这项工作，对基因激活和活性如何响应环境来塑造花表型将获得新的理解。随着气候的变化，这种理解变得更加重要。此外，拟议的研究解决了长期存在的植物交配系统进化问题。虽然环境控制的花表型经常被提到作为一个潜在的途径，以雌雄异株，没有研究探讨这些物种是如何转录相似的雌雄同株或雌雄异株交配系统。这阻碍了我们对植物中一个主要的、重复的进化转变--二萜类化合物的形成途径的理解。在动物中，类似的进化转变发生得太少，而且在进化时间上太久远，以至于无法进行实验研究，因此，如果我们希望了解雌性和雄性是如何以及为什么起源的，我们最好的机会可能在于植物的研究。该奖项反映了NSF的法定使命，并被认为值得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来支持。

Plants reproduce via male and female functions much like animals do. Differently from animals, however, most plants (~90%) combine male and female function in one individual. Even though less than 10% of plant species have separate males and females, this plant mating system has evolved repeatedly in the history of green plants and provides an opportunity to understand its evolution. Moreover, many economically important crops have separate males and females, and often the male or the female is more valuable than the other (e.g., female holly, male gingko), and they can be difficult to distinguish before maturity. In other situations, keeping males and females separate and stable (e.g., female Cannabis, female hops) is necessary to maintain the quality of a product. Despite the importance of this aspect of plant biology economically we know little about factors that determine this expression in plants. This project will research a special group of plants that exhibit separate males and females – those for which the environment controls the expression of male or female function. Chromosomes that determine male or female flower types are rare in plants and species where the environment plays a strong role have the ability to express either male or female flowers, and change from one to the other, during their lives. Changes in gene expression is the most likely mechanism controlling this phenotype in these species thus, this study examines the relationship between gene expression and floral development in maples and makes comparisons to other plant species with different plant mating systems. Understanding more about how gene expression relates to expression of male versus female flowers will help make more economical decisions and plan for population stability in the face of climate change. This project also involves the development of Course-based Undergraduate Research Experiences that include both field elements and training in modern genetic techniques and analysis. It also involves local outreach with a focus on evolutionary biology.Historically several mechanisms that determine male versus female function in organisms has been categorized: genetic, social, temperature dependent, and environmental. This division has resulted in primarily ecologically-based research of species with suspected environmental determination and reinforced a false dichotomy between genetics and environment. This project investigates the transcriptomic underpinnings of environmentally-based plasticity in floral function and seeks answers to the following questions. 1. Are there differences in the amount and kind of gene expression associated with the expression of floral type? 2. To what extent does the transcriptome change during floral development? 3. How similar is the transcriptomic profile of species with this plasticity in comparison to other species? Is it more similar to those exhibiting dioecy or monoecy? Through this work new understanding of how gene activation and activity responds to the environment to shape floral phenotype will obtain. This understanding is becoming more critical with a changing climate. Furthermore, the proposed research addresses long-held questions on the evolution of plant mating systems. Although environmental control of floral phenotype is frequently mentioned as a potential pathway to dioecy, no studies have explored how transcriptomically similar these species are to those with monoecious or dioecious mating systems. This inhibits our understanding of the route to dioecy, a major and repeated evolutionary transition in plants. Similar evolutionary transitions in animals happened too infrequently and too far back in evolutionary time to facilitate experimental investigation, so if we wish to understand how and why females and males originated, our best chance may reside in the study of plants.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.