The Role of KANADI in Promoting Abaxial Cell Fates

KANADI 在促进远轴细胞命运中的作用

• 批准号: 0234347
• 负责人: John Bowman
• 金额: $ 41.5万
• 依托单位: University of California-Davis
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-04-01 至 2007-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0234347&HistoricalAwards=false
• 关键词: Role; KANADI; Promoting; Abaxial; Cell

0234347BowmanLeaves of seed plants are formed from the flanks of apical meristems. Therefore, an inherent positional relationship exists between them: organ primordia have an adaxial side adjacent to the meristem, and an abaxial one away from the meristem. Surgical and genetic studies suggest that a morphogenetic gradient, whose source is the meristem, converts the inherent polarity into a functional one. Once an adaxial-abaxial axis of polarity is established within organ primordia, it provides cues for proper lamina growth and asymmetric development. Several key players involved in this process were identified recently, and analyses of these genes support and refine our views of axis formation in plants. Members of two gene families, the KANADIs and YABBYs, promote abaxial fates, and their expression is confined top the abaxial domains of developing lateral organs. When adaxial factors are active abaxially, the expression of the abaxial factors is eliminated, and vice versa. Thus, the adaxial and abaxial factors are expressed in mutually exclusive domains. The aim of this proposal is the characterization of the KANADIs, focusing on the role of the KANADIs in repressing adaxial factors, and the role of the KANADIs in promoting lamina expansion through the activity of the YABBYs. Experiments are proposed to address whether the interaction between the KANADIs and the adaxial factors and the YABBYs is direct or indirect and whether KANADI dependent lamina expansion is mediated via YABBY activity. Finally, experiments to integrate hypotheses based on classical meristem dissection experiments with genes identified via genetics are proposed. The basic research proposed should provide a foundation of knowledge to facilitate the modification of plant architecture. Since leaves provide the source of the majority of photosynthate, modification of their structure to maximize this process has the potential to increase agricultural productivity in many crop species.

种子植物的叶由顶端分生组织的侧翼形成。因此，它们之间存在一种固有的位置关系：器官原基有一个靠近分生组织的正面，一个远离分生组织的背面。外科和遗传学研究表明，形态发生梯度，其来源是分生组织，将固有极性转化为功能极性。一旦在器官原基中建立了极性的正反轴线，它为适当的层生长和不对称发育提供了线索。最近发现了参与这一过程的几个关键角色，对这些基因的分析支持并完善了我们对植物轴形成的看法。两个基因家族的成员，KANADIs和YABBYs，促进下向命运，它们的表达局限于发育中的外侧器官的下向结构域。当正向因子在背面起作用时，正向因子的表达被消除，反之亦然。因此，轴向因子和轴向因子在互斥域中表示。本提案的目的是描述kanadi的特征，重点关注kanadi在抑制正面因子中的作用，以及kanadi在通过YABBYs的活动促进层扩张中的作用。我们提出了实验来解决KANADI与正面因子和YABBYs之间的相互作用是直接的还是间接的，以及KANADI依赖的层扩张是否通过YABBY活性介导。最后，提出了将基于经典分生组织解剖实验的假设与遗传学鉴定的基因相结合的实验。提出的基础研究应为植物构型的改造提供知识基础。由于叶片提供了大部分光合作用的来源，因此对其结构进行修改以最大限度地发挥这一作用有可能提高许多作物物种的农业生产力。