Comparative studies of the establishment of sexual identity in flowers of non-model species

非模式物种花朵性别认同建立的比较研究

• 批准号: RGPIN-2021-02431
• 负责人: Lacroix, Christian
• 金额: $ 2.4万
• 依托单位: University of Prince Edward Island
• 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=741944
• 关键词: Comparative; studies; establishment; sexual; identity

I use a comparative approach to study the structure and developmental potential of meristems, which are regions of actively dividing cells in plants. Comparative developmental studies are used to elucidate patterns and develop testable hypotheses on how genetic pathways can be altered to lead to morphologically different forms. The central goal of my research program is to gain a better understanding of early developmental events at the level of meristems that lead to the form of mature plants organs using species that exhibit uncommon morphologies. My short-term objectives focus on studies dealing with homeosis in flowers. Homeosis refers to the growth of specific types of organs in sectors where they normally don't develop. I will study this phenomenon in two systems: Aroids (Araceae) and Hibiscus (Malvaceae). 1. Cylindrical inflorescences of Aroids: A number of Aroid species with cylindrical inflorescences consist of male flowers in the upper portion and females in the lower portion, as well as a sector of bisexual flowers between these two zones. These bisexual flowers represent a unique case of homeosis where female organs (aka carpels) are replaced by male organs (aka stamens) on the same whorl. 2. 'Double' flowers of Hibiscus: In Hibiscus rosa-sinensis, double flowers produce a number of stamens as well as petaloid floral organs on a donut-shaped meristematic ring normally designated exclusively for stamen production in typical flowers. In both systems, I want to determine if there are general relationships that characterize the substitution of one type of organ by another to uncover potential developmental constraints and underlying mechanisms. Additionally, I plan to identify floral organ identity gene homologues and their patterns fo expression during early stages of initiation and development. I also plan to use sequencing techniques to compare transcriptomes (gene expression profiles) of male, female, and atypical flowers in Aroids. 3. Real time morphogenesis technique development: Although developmental series of floral organs are reported in the literature, they are mainly based on an assemblage of several sequential 'static' developmental stages. There are very few studies that have attempted to document development in real time using a single meristem because of inherent limitations that prevent continuous track of morphogenesis without eliciting damage.  Preliminary work in our laboratory combining the micro culture of meristematic tissues and scanning electron microscopy shows great promise as a useful approach to capture and characterize the dynamic nature of the relationship between a meristem and the organs it forms. The main objective of this study will be to quantitatively analyze the relationships between the size of floral primordia and the size of inflorescence meristem in Aroids; similarly we will also analyze the size and shape of floral organs in relation to the size and shape of the floral meristem in Hibiscus.

我使用比较方法来研究分生组织的结构和发育潜力，分生组织是植物中活跃分裂细胞的区域。比较发育研究用于阐明模式并提出可检验的假设，以了解如何改变遗传途径以导致形态上不同的形式。我的研究计划的中心目标是更好地了解分生组织水平的早期发育事件，这些事件导致使用表现出不常见形态的物种形成成熟植物器官的形式。我的短期目标集中在处理花卉同源异质的研究上。同质异位是指特定类型的器官在通常不发育的部位生长。我将在两个系统中研究这种现象：天南星科（天南星科）和木槿科（锦葵科）。 1. 天南星的圆柱形花序：许多具有圆柱形花序的天南星物种由上部雄花和下部雌花组成，以及在这两个区域之间的两性花部分。这些双性花代表了同源异型的独特情况，其中雌性器官（又名心皮）被同一轮生的雄性器官（又名雄蕊）取代。 2.木槿的“双”花：在木槿中，双花在甜甜圈形分生环上产生许多雄蕊和花瓣状花器官，通常专门用于典型花朵中雄蕊的产生。 在这两个系统中，我想确定是否存在表征一种器官被另一种器官替代的一般关系，以揭示潜在的发育限制和潜在机制。此外，我计划鉴定花器官特征基因同源物及其在起始和发育早期阶段的表达模式。我还计划使用测序技术来比较天南星属雄性、雌性和非典型花的转录组（基因表达谱）。 3.实时形态发生技术的发展：虽然文献中报道了花器官的发育系列，但它们主要基于几个连续的“静态”发育阶段的组合。很少有研究尝试使用单个分生组织实时记录发育情况，因为固有的局限性阻碍了形态发生的连续跟踪而不引起损伤。  我们实验室的初步工作结合了分生组织的微培养和扫描电子显微镜，显示出作为捕获和表征分生组织与其形成的器官之间关系的动态性质的有用方法的巨大前景。本研究的主要目的是定量分析天南星科植物花原基大小与花序分生组织大小之间的关系；同样，我们还将分析木槿花器官的大小和形状与花分生组织的大小和形状的关系。