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.

我使用比较的方法来研究分生组织的结构和发展潜力，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，并就遗传途径如何改变以导致形态不同的形式提出可检验的假说。我的研究计划的中心目标是更好地了解分生组织水平上的早期发育事件，这些事件导致成熟植物器官的形成，使用表现出不常见形态的物种。我的短期目标是研究花的同源异位体。同源异体是指特定类型的器官在正常情况下不发育的部门生长。我将在两个系统中研究这种现象：天南星科(天南星科)和木槿属(锦葵科)。1.柱状花序：许多具有柱状花序的类群植物由上部的雄花和下部的雌花组成，以及这两个区域之间的一段两性花。这些两性花代表了一种独特的同源共生现象，即雌性器官(又名心皮)被同一轮上的雄性器官(又名雄蕊)所取代。2.木槿花：在芙蓉属中，重瓣花在甜甜圈状的分生组织环上产生许多雄蕊和花瓣状的花器官，通常专用于典型花的雄蕊生产。在这两个系统中，我想确定是否存在以一种类型的器官被另一种类型的器官替代为特征的一般关系，以揭示潜在的发育限制和潜在的机制。此外，我计划确定花器官识别基因同源物及其在启动和发育的早期阶段的表达模式。我还计划使用测序技术来比较Aroid中雄花、雌花和非典型花的转录(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，但它们主要是基于几个连续的静态发育阶段的组合。很少有研究试图使用单个分生组织来实时记录发育，因为固有的限制阻碍了形态发生的连续跟踪而不会引起损害。我们实验室的初步工作结合了分生组织的显微培养和扫描电子显微镜，显示了作为捕捉和表征分生组织及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菊科植物花原基的大小和花序分生组织的大小之间的关系；同样，我们还将分析木槿属花器官的大小和形状与花分生组织的大小和形状的关系。