Functional diversification of class1 KNOX genes in basal eudicots

KNOX基因是一个同源异型盒基因家族，是植物新梢发育的重要调节基因。KNOX基因是茎顶端分生组织持续生长所必需的，而叶的形成则需要KNOX基因的下调。在几个被子植物谱系中，KNOX基因在控制叶片剥离方面的额外功能已经进化。然而，与叶片形状改变相关的KNOX基因作用的进化变化还不是很清楚。本项目旨在研究这一小基因家族的特征及其在桉树基生植物海棠叶片发育中的作用。由于其解剖的叶片，其在核心真子植物和基生被子植物之间的系统发育位置，以及可利用的发育基因技术，Eschascizia提供了一个独特的系统。此外，近缘物种的发育模式不同也会引起家族内部的比较。为了了解解剖叶片的发育，我们将首先研究Eschschschzia和近缘属Chelidonium中的第一类KNOX基因及其表达模式。其次，将利用农杆菌介导的转化和病毒诱导的基因沉默来确定调控表达的表型效应在埃希尔齐亚中的作用。为了进一步评估KNOX基因在石杉和其他物种之间，以及解剖和单叶之间的作用差异，我们将研究它与其他基因和植物激素的相互作用。与其他物种的比较将有助于我们理解诺克斯基因的多样性如何与形态进化有关。

KNOX genes are a family of homeobox genes that are essential regulators of plant shoot development. KNOX genes are required for continued growth of the shoot apical meristem, and leaf formation requires KNOX genes to be downregulated. In several angiosperm lineages, an additional function of KNOX genes in the control of leaf dissection has evolved. However, evolutionary changes of KNOX gene action associated with modifications of leaf forms are not well understood. This project aims to characterize this small gene family and its role in leaf development in the basal eudicot plant Eschscholzia californica. Eschscholzia provides a unique system because of its dissected leaves, its phylogenetic position between core eudicots and basal angiosperms, and the availability of developmental genetic technologies. In addition, contrasting developmental patterns in related species invite within-family comparisons. To understand dissected leaf development, we will firstly characterize the class 1 KNOX genes and their expression patterns in Eschscholzia and the related genus Chelidonium. Secondly, phenotypic effects of modulated expression will be determined in Eschscholzia, using Agrobacterium-mediated transformation and Virus-induced gene silencing. To further assess differences in the action of KNOX genes between Eschscholzia and other species, and between dissected and simple leaves, the interaction with other genes and with phytohormones will be studied. Comparisons with other species will promote our understanding of how diversification of KNOX genes is implicated in morphological evolution.