Epidermal specification mutants of Arabidopsis

有机体的发育需要专门组织的连续产生。植物表皮是一个特别有趣的组织，因为它是最早形成的组织之一，但它在植物的整个生命过程中不断分化，经历特化以吸收营养，优化光合作用产量，并确保生殖成功。本研究的目的是鉴定表皮的初始形成和后来一组特殊表皮类型——胚珠被的发育所需要的分子。该方法将通过突变来确定(1)胚胎中表皮表达的报告基因正确定位所需的基因，(2)通过筛选干扰种子形状和粘液产生的突变来确定被珠的规格所需的基因。这些突变体将根据它们在几种表皮图案决定中的作用来表征，并克隆出最有趣的突变体。通过分析这些突变获得的信息将提示组织启动、扩展和保持其特性的方式。这一信息可能揭示了其他组织类型共同建立的调控回路，或者它可能表明表皮具有独特的发育模式，与其作为植物与外界之间的界面的功能有关。对于农作物的改良，关于表皮的知识对于植物防御的理解和工程以及植物生物材料的生产尤其重要。

Development of an organism requires the successive generation of specialized tissues. The plant epidermis is a particularly interesting tissue because it one of the first to be established, yet it continues to differentiate throughout the life of the plant, undergoing specialization to take up nutrients, optimize photosynthetic yields, and ensure reproductive success. The objective of this study is to identify molecules required for the initial formation of the epidermis and later for the development of one set of specialized epidermal types, the ovule integuments. The approach will be to identify, by mutation, (1) genes that are required for the correct localization of an epidermally-expressed reporter gene in the embryo, and (2) genes required for the specification of the integuments by screening for mutants that disturb seed shape and mucilage production. The mutants will be characterized with respect to their role in several epidermal patterning decisions, and the most interesting ones cloned. The information garnered by the analysis of these mutations will suggest ways in which a tissue initiates, expands and maintains its identity. This information may reveal regulatory circuits that are common to the establishment of other tissue types, or it may show that the epidermis has unique developmental patterns that relate to its functional role as the interface between the plant and the outside world. For the improvement of crop plants, knowledge about the epidermis is particularly relevant for the understanding and engineering of plant defenses and for production of plant biomaterials.