Phylogeny and the evolution of succulence in the Portulacineae (Caryophyllales)

生活在世界干旱地区的许多植物通常通过长期储存植物不同部位的水分来生存。这些植物通常被描述为“多汁的”。每个人一看到多汁的植物就知道它是什么，它们奇特的形状使它们受到园艺家和收藏家的欢迎。尽管它们无处不在，但科学家们对植物中极端多肉的进化过程知之甚少。在这个项目中，将在包括仙人掌在内的约2000种开花植物的不同谱系中研究肉质植物的进化。将从大约500个物种收集分子数据，以重建群体内的进化关系。“成功”将使用一种新设计的测量方法进行量化表征。在这个新的框架内，将测试一系列关于植物肉质如何以及为什么多次进化的假设。该项目将为促进植物耐旱性的机制提供新的见解，这可能有助于预测不同植物谱系对未来气候变化的反应。该项目将为博士后、研究生和本科生提供广泛的培训机会，包括女性和少数民族学生。该项目还包括一项重要的公共宣传活动，国际植物保护协会和学生将制作一系列关于植物进化的动画短片。这些电影将为高中生物背景的个人设计，并将在非常受欢迎的网站creaturecast.org上播出。

Many plants that inhabit the arid regions of the world commonly survive by long-term storage of water in various parts of the plants. These plants are typically described as 'succulent'. Everyone knows a succulent plant when they see one, and their bizarre forms have made them popular with horticulturists and collectors. In spite of their ubiquity, scientists know very little about how extreme succulence has evolved in plants. In this project, the evolution of succulence will be investigated in a diverse lineage of ~2,000 flowering plants that include the cacti. Molecular data will be collected from ~500 species to reconstruct evolutionary relationships within the group. 'Succulence' will be characterized in quantitative terms using a newly devised measurement. Within this new framework a series of hypotheses will be tested regarding how and why succulence has evolved multiple times in plants. The project will provide novel insights into the mechanisms that have promoted drought tolerance in plants, which may help predict responses of different plant lineages to future climate change. The project will provide extensive training opportunities for post-doctoral, graduate, and undergraduate scholars, including female and minority students. The project also includes a significant public outreach effort where the PI and students will create a series of short animated films about plant evolution. These films will be designed for individuals with a high-school level biology background, and will be broadcast on the extremely popular website 'creaturecast.org'.