RUI: Regulation of Inflorescence Architecture in Pea

RUI：豌豆花序结构的调控

• 批准号: 9977087
• 负责人: Susan Singer
• 金额: $ 33.18万
• 依托单位: Carleton College
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-08-15 至 2005-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9977087&HistoricalAwards=false
• 关键词: RUI; Regulation; Inflorescence; Architecture; Pea

Inflorescence architecture, the patterning of reproductive branches, affects fruit and seed yield in natural and agricultural settings. The diversity of architectural patterns contrasted with the highly conserved nature of essential flowering genes provides an intriguing puzzle for developmental and evolutionary biologists. Multiple pathways lead to inflorescence development. An in-depth comparative analysis of several model systems with distinct inflorescence typologies will lead to an understanding of the shared pathways in inflorescence development, as well as the genetic modifications resulting in diversification of inflorescence types. Pea (Pisum sativum) is a good model system for the comparative analysis of inflorescence development because it has a one-step more complex inflorescence (compound vs. simple raceme) than the extensively studied Arabidopsis and Antirrhinum systems. Also, homologs of two key flowering genes in Arabidopsis and Antirrhinum have been cloned and have a mutant phenotype in pea: PFLO[unifoliata (uni)] and PSQUA [proliferating inflorescence meristem (pim-1]. The mutant phenotypes are similar to those in the other systems, but have distinctive effects on the overall architecture of the plant. Ten genes have been identified that have a primary role in specific regions of the inflorescence. A model will be constructed explaining how these genes interact with themselves, the environment, and genes that regulate flowering time through the production or control of transport of a floral inhibitor and a floral promoter. Two genes that regulate inflorescence development will be investigated. Mutants of COCHLEATA (COCH) affect both vegetative and reproductive growth. A subtle asymmetry in size and shape of stipule pairs is greatly enhanced in each of the four coch alleles being investigated. This results in a 'front-back' asymmetry that is inconsistent with a model of leaves being initiated spirally. COCH is responsible for a graft transmissible factor. Wild-type scions grafted onto coch mutants develop aberrant flowers similar to those found in the mutants. Sepal number varies and secondary flowers often form in the axil of the first sepal initiated. The double mutant coch pim-1 does not flower which is indicative of two partially redundant pathways of flowering. The role of COCH in regulating shoot architecture will be analyzed by: 1) developmental morphological studies; 2) grafting and tissue culture experiments; 3) investigation of interactions of coch with other flowering mutants and environmental factors; 4) genetic and histological comparisons of the stipules and sepals in coch and COCH plants to assess the relationships between leaves and sepals; 5) investigations of the expression patterns of the PFLO and PSQUA in coch; and 6) testing of the hypothesis that COCH is the homolog of FRUITFULL (FUL) in Arabidopsis, since ful-1 has many phenotypic similarities to coch. Genes that regulate the number of pods produced by an axillary inflorescence branch will also be characterized. Understanding how inflorescence development is regulated has the potential to increase crop yield.

花序结构，生殖枝的图案，影响自然和农业环境中的果实和种子产量。 结构模式的多样性与基本开花基因的高度保守性形成对比，这为发育和进化生物学家提供了一个有趣的难题。 多种途径导致花序发育。 深入比较分析几个模式系统与不同的花序类型学将导致在花序发育的共同途径的理解，以及遗传修饰导致花序类型的多样化。 豌豆（Pisum sativum）是比较分析花序发育的良好模式系统，因为它具有比广泛研究的拟南芥和金鱼草系统更复杂的一步花序（复合总状花序与简单总状花序）。 此外，拟南芥和金鱼草中两个关键开花基因的同源物已被克隆，并在豌豆中具有突变表型：PFLO[unifoliata（uni）]和PSQUA [增殖花序分生组织（pim-1）]。 突变体表型与其他系统中的表型相似，但对植物的整体结构具有独特的影响。 已经确定了10个基因在花序的特定区域中具有主要作用。 将构建一个模型来解释这些基因如何与自身、环境以及通过生产或控制成花抑制剂和成花启动子的运输来调节开花时间的基因相互作用。 两个基因调控花序发育将进行调查。 COCH突变体影响营养生长和生殖生长。 一个微妙的不对称的托叶对的大小和形状是大大加强了四个coch等位基因正在调查。 这导致了“前后”不对称，这与叶子被启动的模式不一致。 COCH是一种移植物传播因子。 嫁接到coch突变体上的野生型接穗会产生与突变体中发现的类似的异常花朵。 萼片数量不等，次生花通常在第一个萼片起始的腋处形成。 双突变体coch pim-1不开花，这表明两个部分冗余的开花途径。 本论文通过以下几个方面分析了COCH在调控茎结构中的作用：1）发育形态学研究; 2）嫁接和组织培养实验; 3）COCH与其它开花突变体和环境因子的互作研究; 4）COCH和COCH植物的托叶和萼片的遗传和组织学比较，以评估叶片和萼片之间的关系; 5）研究coch中PFLO和PSQUA的表达模式; 6）测试COCH是拟南芥中FRUITFULL（FUL）的同源物的假设，因为ful-1与coch具有许多表型相似性。 还将表征调节由腋生花序分支产生的荚的数量的基因。 了解花序发育是如何调节的有可能提高作物产量。