Control of Phyllotaxy in Maize by ABPHYL1, a Cytokinin Inducibe Response Regulator Homolog

ABPHYL1（一种细胞分裂素诱导反应调节剂同系物）对玉米叶序的控制

• 批准号: 0344738
• 负责人: David Jackson
• 金额: $ 42万
• 依托单位: Cold Spring Harbor Laboratory
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-03-01 至 2007-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0344738&HistoricalAwards=false
• 关键词: Control; Phyllotaxy; Maize; ABPHYL1; Cytokinin

Plant shape or architecture has a major impact on agricultural yields. Architecture is the end product of morphogenesis, which in plants, as in animals, commences during early embryogenesis with the development of distinct organ and tissue types. Plant development proceeds through the continuous initiation of organs from groups of stem cells called meristems. All of the shoot organs, such as leaves and flowers, are initiated from the shoot meristem in regular patterns known as phyllotaxies. How these patterns are generated has been a subject of interest for centuries, and has been of interest to mathematicians, physicists and biologists. Initiation of organs in regular patterns can optimize light capture for efficient photosynthesis, and in some plants generates architectural support.In this proposal Dr. Jackson will study the ABPHYL1 (ABPH1) gene of maize. Loss of ABPH1 function causes plants to develop with opposite and decussate phyllotaxy rather than the alternating or distichous pattern that is normal for maize. The ABPH1 gene encodes a cytokinin inducible response regulator homolog, and though this gene family has been known for several years this is the first report of a loss of function phenotype in one of these genes. Response regulators were first discovered in bacteria and function in signaling pathways. Therefore these studies will investigate the link between a unique developmental question and a novel function for a gene predicted to transduce cytokinin signals in plants. In particular, the expression of ABPH1 protein and mRNA will be described in relation to its role in phyllotaxy, and the effect of cytokinins on its expression will also be documented. The hypothesis that cytokinins may regulate phyllotaxy will also be tested, by growing shoot explants or embryos on medium containing exogenous cytokinin. Finally, microarray analysis will be used to identify genes that are regulated by ABPH1, and some of these will be characterized by genetic analysis. These studies should contribute to several areas of biology, including developmental regulation, morphogenesis, signaling and activity of growth regulators. Importantly, they should foster interactions between hormone biologists and developmental biologists. The proposed studies will also be of interest to researchers in other disciplines, such as mathematics and biophysics.

植物形状或结构对农业产量有重大影响。 建筑是形态发生的最终产物，在植物中，就像在动物中一样，建筑在早期胚胎发生过程中开始，并发育出不同的器官和组织类型。植物的发育是通过称为分生组织的干细胞群不断形成器官来进行的。所有的芽器官，例如叶和花，都是从芽分生组织以规则的模式（称为叶序）开始的。几个世纪以来，这些模式是如何生成的一直是数学家、物理学家和生物学家感兴趣的话题。 器官以规则模式启动可以优化光捕获以实现高效的光合作用，并且在某些植物中产生结构支持。在这项提案中，杰克逊博士将研究玉米的 ABPHYL1 (ABPH1) 基因。 ABPH1 功能的丧失会导致植物发育为相反的交叉叶序，而不是玉米正常的交替或二列模式。 ABPH1 基因编码细胞分裂素诱导反应调节剂同系物，尽管该基因家族已为人所知数年，但这是这些基因之一功能表型丧失的首次报道。反应调节因子首先在细菌中发现并在信号通路中发挥作用。因此，这些研究将调查独特的发育问题与预测在植物中转导细胞分裂素信号的基因的新功能之间的联系。 特别是，ABPH1 蛋白和 mRNA 的表达将与其在叶序中的作用相关地描述，并且细胞分裂素对其表达的影响也将被记录。 细胞分裂素可能调节叶序的假设也将通过在含有外源细胞分裂素的培养基上生长芽外植体或胚胎进行测试。 最后，微阵列分析将用于鉴定受 ABPH1 调节的基因，其中一些基因将通过遗传分析进行表征。 这些研究应该对生物学的多个领域做出贡献，包括发育调节、形态发生、信号传导和生长调节剂的活性。 重要的是，他们应该促进激素生物学家和发育生物学家之间的互动。拟议的研究也会引起其他学科（例如数学和生物物理学）的研究人员的兴趣。