The Evolution and Development of Compound Leaves

叶片在光合作用中起着捕获光的作用，对植物个体的生存和全球范围内的能量交换都至关重要。 根据它们的形态，叶子可以大致分为两类，简单的和复合的。 这些叶子中的每一个都可能比另一个有优势，这取决于它们进化的环境。 然而，在自然界中看到的各种叶子形式的发展基础在很大程度上是未探索的。 Sinha博士利用遗传、分子和发育工具对模式生物番茄的复叶形状进行了系统的解剖。 当从简单的叶模式物种的结果相比，这些结果向我们表明，复合和简单模式的叶发育之间的共性和分歧。 她之前的研究结果表明，1类KNOTTED-like HOMEOBOX（KNOX 1）基因在番茄（具有复叶）和拟南芥（具有单叶）中的功能不同，随后的数据表明，KNOX 1基因在大多数开花植物的复叶发育级联中被利用。 Sinha博士将这项研究扩展到分析PHANTASTICA的作用，PHANTASTICA是一种调节KNOX 1基因的MYB结构域蛋白。在番茄叶片发育中，PHAN和KNOX 1具有剂量敏感的调节关系，并且PHAN调节许多复叶中的小叶位置。 虽然这些已知的基因是叶复杂性的重要决定因素，这项工作也将确定其他迄今未探索的基因在复叶发育中发挥的作用。 这项研究涉及分析番茄和豆类家族中的叶发育，以及芥菜家族中同一属（例如独行菜属）或同一物种（例如异胚物种Neobeckia aquatica）中的相关物种。 这项研究包括发育生物学，分子生物学，植物生理学，遗传学和进化生物学领域，长期目标是在进化背景下彻底解剖复叶发育。

Leaves function in photosynthetic light capture and are critical both to individual plant survival and to energy exchanges on a global scale. Based on their morphology leaves can be broadly grouped into two categories, simple and compound. Each of these leaves may have advantages over the other depending on the environment in which they evolved. However, the developmental basis for the various leaf forms seen in nature is largely unexplored. Dr. Sinha has undertaken a systematic dissection of compound leaf shape in the model organism tomato using genetic, molecular and developmental tools. When compared to results from simple leafed model species, these results suggest to us the commonalities and divergences between the compound and simple modes of leaf development. Her previous results suggested that the Class 1 KNOTTED-like HOMEOBOX (KNOX1) genes function differently in tomato (with compound leaves) and Arabidopsis (with simple leaves) and subsequent data showed that KNOX1 genes are utilized in the developmental cascade leading to compound leaves in most flowering plants. Dr. Sinha has extended this study to analyze the role of PHANTASTICA, a MYB domain protein that regulates KNOX1 genes. In tomato leaf development PHAN and KNOX1 share a dosage sensitive regulatory relationship and PHAN regulates leaflet placement in numerous compound leaves. While these known genes are important determinants for leaf complexity, this work will also identify roles that other heretofore unexplored genes play in compound leaf development. This research involves analysis of leaf development in the tomato and bean families, and in related species in the same genus (e.g. the genus Lepidium) or within the same species (e.g. the heteroblastic species Neobeckia aquatica) in the mustard family. This research encompasses the areas of developmental biology, molecular biology, plant physiology, genetics, and evolutionary biology and the long-term goals are to thoroughly dissect compound leaf development in an evolutionary context.