Molecular Specification and Development of the Carpel Margin Meristem

心皮边缘分生组织的分子规格和发育

• 批准号: 0416759
• 负责人: Robert Franks
• 金额: --
• 依托单位: North Carolina State University
• 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: 2004-09-01 至 2009-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0416759&HistoricalAwards=false
• 关键词: Molecular; Specification; Development; Carpel; Margin

Project SummaryThe survival of seed plants, and thus the security of humankind's food supply, requires the development of ovules that when fertilized will develop into seeds. In flowering plants the ovules develop within the gynoecium, the female reproductive structure. In Arabidopsis thaliana the gynoecium is made up of two carpels that are fused along their edges or margins to form a tube-like structure. Ovules arise on the inner surface of the gynoecial tube from specialized meristematic regions known as the Carpel Margin Meristems (CMMs). Genetic mutations that disrupt the development of the CMM result in a reduction of seed formation. Thus proper development of the CMMs is critical for female fertility in Arabidopsis and agricultural productivity in many crop plants. The main objective of the proposed research is to generate an understanding of the molecular mechanisms of early CMM development.Regional specification within the developing gynoecium refers to the assignment of different positional identities to different parts of the structure. Regional specification is critical for the development of the CMM. Specifically, adaxial (or inner) identity and margin identity must be properly specified to ensure CMM formation and thus ovule development. Experimental data indicates that three key regulatory genes, SEUSS, LEUNIG and AINTEGUMENTA, play a crucial role in the early development of the CMM. Dr Franks proposes a bipartite model in which 1) the SEUSS, LEUNIG and AINTEGUMENTA genes are required for the expression of the adaxial identity marker PHABULOSA within the developing gynoecium and 2) PHABULOSA expression is critical for the early development of the CMM. He proposes a variety of molecular genetic experiments to thoroughly test this model: 1) specific molecular markers will be used to follow regional specification during gynoecial development in mutant plants in which the activity of one or more of above-mentioned key regulators (SEUSS, LEUNIG and AINTEGUMENTA) is compromised; 2) the expression patterns of the SEUSS and LEUNIG gene products within the developing gynoecium will be determined; 3) the significance of adaxial identity specification during CMM development by the PHABULOSA gene will be investigated; 4) and a unique genetic modifier screen will be utilized to identify novel regulators of CMM development. In many crop plants the development of the CMM is critical for agricultural productivity. By generating an enhanced molecular understanding of the regulation and control of CMM development, the proposed research may enable methods to engineer agricultural varieties with enhanced yield and thus meet the growing global demand for food. Additionally, the PI will enhance the societal benefits of his research program by fully integrating his scientific research efforts with his graduate and undergraduate teaching and training responsibilities. Materials and research results will be widely dispersed through publication in scientific journals and through web-based vehicles to interested scientists and all levels of educators. Furthermore, Dr. Franks will organize interested graduate students to prepare and present demonstrations at local elementary schools that will help to encourage an interest in scientific studies from this early age.

种子植物的生存，以及人类食物供应的安全，需要胚珠的发育，受精后将发育成种子。在开花植物中，胚珠在雌蕊群（雌性生殖结构）内发育。在拟南芥中，雌蕊群由两个心皮组成，心皮的边缘沿着融合形成管状结构。胚珠从称为心皮边缘分生组织（CMMs）的特化分生组织区域产生于雌蕊管的内表面。破坏CMM发育的基因突变导致种子形成减少。因此，CMMs的适当发育对于拟南芥的雌性生育力和许多作物植物的农业生产力至关重要。拟议的研究的主要目标是产生一个早期CMM的分子机制的理解development.Regional规格内发展雌蕊群是指分配不同的位置身份的不同部分的结构。区域规范对于CMM的发展至关重要。 具体地说，近轴（或内部）身份和边缘身份必须适当指定，以确保CMM的形成，从而胚珠的发展。实验数据表明，三个关键的调控基因，SEUSS，LEUNIG和AINTEGUMENTA，在CMM的早期发展中起着至关重要的作用。Franks博士提出了一个二分模型，其中1）SEUSS，LEUNIG和AINTEGUMENTA基因是发育中的雌蕊群中近轴身份标记PHABULOSA表达所必需的，2）PHABULOSA表达对CMM的早期发育至关重要。他提出了多种分子遗传学实验来彻底检验这一模型：1）将使用特定的分子标记来跟踪突变体植物雌蕊群发育期间的区域特化，其中一种或多种上述关键调节因子的活性（SEUSS、LEUNIG和AINTEGUMENTA）受损; 2）将确定SEUSS和LEUNIG基因产物在发育中的雌蕊群内的表达模式; 3）将研究PHABULOSA基因在CMM发育过程中近轴身份特化的意义; 4）将利用独特的遗传修饰剂筛选来鉴定CMM发育的新调节剂。在许多农作物中，CMM的发展对农业生产力至关重要。通过增强对CMM发展的调控和控制的分子理解，拟议的研究可能使方法能够设计具有提高产量的农业品种，从而满足日益增长的全球食品需求。 此外，PI将通过将他的科研工作与他的研究生和本科生教学和培训责任充分结合起来，提高他的研究计划的社会效益。材料和研究成果将通过在科学期刊上发表和通过网络工具向感兴趣的科学家和各级教育工作者广泛传播。此外，弗兰克斯博士将组织感兴趣的研究生在当地小学准备和展示演示，这将有助于鼓励从小对科学研究的兴趣。