Evolution of floral and fruit traits in the Brassicales

芸苔目花和果实性状的演变

• 批准号: RGPIN-2019-05454
• 负责人: Hall, Jocelyn
• 金额: $ 2.4万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=738306
• 关键词: Evolution; floral; fruit; traits; Brassicales

Despite our fascination with the diversity of forms observed in plants, our understanding of how this variation has arisen is limited. As such, "What is the basis of morphological variation?" remains a key question in evolutionary biology. The goal of my research is to decipher changes that result in different forms of flowers and fruits. Floral traits are clearly important for pollinator interactions, yet there is a notable gap in our knowledge of evolutionary processes that underlie these features that may influence pollinator behaviour. Detailed knowledge of fruit developmental genetics and evolution is essential because seed dispersal is important for structuring plant communities and represents a key component of plant fitness. I study two closely related plant groups that represent an exemplary system because they vary in important floral and fruit traits. They are also closely related to the leading genetic model plant, facilitating a more informed supposition of which genetic changes may be involved to generate novel traits. Cleomaceae (spider flower family) exhibit many different types of flowers, including variation in the gland that provides nectar for pollinators and an unusual stalk that elevates reproductive structures. These features are understudied across angiosperms despite their clear relationships to pollination biology. A group within the mustard family is important because it includes crop species (e.g. canola, broccoli) and because the fruits are often segmented, a trait that dramatically alters seed dispersal. This complex trait has evolved multiple times, leading to the fundamental question of whether the same modification in fruit patterning pathways underlie separate evolutionary events. I take a comprehensive approach that combines multiple disciplines and, as such, will lead to substantial advancements in understanding plant evolution as well as provide broad training for Highly Qualified Personnel. Developmental studies will be conducted on a range of species. This approach provides fundamental data on how mature fruits and flowers are formed, which facilitates hypotheses on what genes may be responsible for morphological differences when combined with knowledge of genetics in model species. We will combine these data for a thorough picture of how traits have changed through time. Further we will test whether key traits evolve together and are correlated with increased number of species. We will describe patterns of comparative gene expression using multiple approaches, which are valuable in correlating a particular morphology with a gene expression pattern. For example, observing the same expression patterns in multiple genes in two species supports the hypothesis that the same pathway has been recruited in different evolutionary origins. Finally, we propose to move beyond correlation and conduct experiments that will directly test how these genes function in our system.

尽管我们对观察到的植物形态的多样性着迷，但我们对这种变化是如何产生的理解有限。因此，“形态变异的基础是什么？”仍然是进化生物学中的一个关键问题。我研究的目的是破译导致不同形式的花朵和果实的变化。显然，花的性状对传粉者的相互作用很重要，然而，我们对这些可能影响传粉者行为的特征背后的进化过程的了解还存在明显的差距。果实发育遗传学和进化的详细知识是必不可少的，因为种子传播对植物群落的结构很重要，并且代表了植物适应性的关键组成部分。我研究了两个密切相关的植物群，它们代表了一个示范系统，因为它们在重要的花和果实性状上各不相同。它们也与主要的遗传模式植物密切相关，有助于更明智地推测哪些遗传变化可能涉及产生新性状。Cleomaceae（蜘蛛花家族）展示了许多不同类型的花，包括为传粉者提供花蜜的腺体的变异和提高生殖结构的不寻常的茎。尽管这些特征与授粉生物学有明确的关系，但被子植物的这些特征尚未得到充分研究。芥菜科中的一个群体很重要，因为它包括作物物种（如油菜、西兰花），而且果实通常是分节的，这一特征极大地改变了种子的传播。这种复杂的性状已经进化了多次，导致了一个基本的问题，即果实图案路径的相同修改是否构成了不同进化事件的基础。我采取综合的方法，结合多个学科，因此，将导致对植物进化的理解取得实质性进展，并为高素质人才提供广泛的培训。将对一系列物种进行发育研究。这种方法提供了成熟果实和花朵如何形成的基本数据，结合模式物种的遗传学知识，有助于假设哪些基因可能负责形态差异。我们将把这些数据结合起来，以全面了解性状是如何随着时间而变化的。进一步，我们将测试关键性状是否一起进化，是否与物种数量的增加有关。我们将使用多种方法描述比较基因表达的模式，这在将特定形态与基因表达模式相关联方面是有价值的。例如，在两个物种的多个基因中观察到相同的表达模式支持了相同途径在不同进化起源中被招募的假设。最后，我们建议超越相关性，进行实验，直接测试这些基因在我们系统中的功能。