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

我用比较的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。比较发育研究是用来阐明模式和发展可测试的假设，如何遗传途径可以改变，导致形态不同的形式。我的研究计划的中心目标是更好地理解在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，使用表现出不寻常形态的物种。我的短期目标是研究花的同型异体。同种异体是指特定类型的器官在它们通常不发育的部位生长。我将研究这一现象的两个系统：天南星科和芙蓉科。1. 柱形花序：许多柱形花序的石菖苣属植物由上部雄花和下部雌花组成，在这两个区域之间有两性花。这些两性花代表了一种独特的同型异体现象，即在同一个轮生上，雌性器官（即心皮）被雄性器官（即雄蕊）所取代。2. 芙蓉花的“重瓣”花：在芙蓉花中，重瓣花在一个环形的分生组织环上产生许多雄蕊和花瓣状的花器官，通常在典型的花中专门用于产生雄蕊。在这两个系统中，我想确定是否存在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的机制。此外，我计划确定花器官识别基因同源物及其在早期萌发和发育阶段的表达模式。我还计划使用测序技术来比较雄性、雌性和非典型花的转录组（基因表达谱）。实时形态发生技术发展：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实时记录发育，因为固有的局限性阻止了在不引起损伤的情况下连续跟踪形态发生。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，显示出作为一种有用的方法来捕捉和表征分生组织与其形成的器官之间关系的动态性质的巨大希望。本研究的主要目的是定量分析石竹属植物花原基大小与花序分生组织大小的关系；同样，我们也将分析与芙蓉花分生组织的大小和形状有关的花器官的大小和形状。

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.