RUI: Regulation of Inflorescence Architecture in Pea

花序结构是生殖枝的图案，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，为发育和进化生物学家提供了一个有趣的谜题。花序发育有多种途径。对几种不同花序类型的模式系统进行深入的比较分析，将有助于理解花序发育的共同途径，以及导致花序类型多样化的遗传修饰。豌豆是比较分析花序发育的一个很好的模式系统，因为它的花序比被广泛研究的拟南芥和金鱼草系统复杂一步(复合或简单总状花序)。此外，拟南芥和金鱼草中两个关键开花基因的同源基因已经被克隆，并且在豌豆中具有突变的表型：PFLO[unifoliata(Uni)]和PSQUA[增殖花序分生组织(Pim-1)]。突变的表型与其他系统中的类似，但对植物的整体结构有不同的影响。已经确定了10个在花序特定区域起主要作用的基因。将构建一个模型，解释这些基因如何与自身、环境以及通过生产或控制花抑制物和花启动子的运输来调节开花时间的基因相互作用。两个调控花序发育的基因将被研究。耳蜗虫突变体(Cochleata，Coch)对营养生长和生殖生长都有影响。在被研究的四个Coch等位基因中，托叶对在大小和形状上的细微不对称都大大增强了。这导致了一种“前后”的不对称，这与叶片螺旋启动的模型不一致。Coch是移植物的一个传播因素。嫁接到Coch突变体上的野生型接穗发育出与突变体中发现的类似的畸形花。萼片数目不同，次生花通常形成于第一个被启动的萼片的腋处。双突变体Coch Pim-1不开花，这表明有两条部分冗余的开花途径。Coch在调控新梢构型中的作用将通过以下几个方面进行分析：1)发育形态研究；2)嫁接和组织培养实验；3)Coch与其他开花突变体和环境因素的相互作用；4)Coch和Coch植物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；以及6)验证Coch是拟南芥中FRUITFULL(FUL)的同源物的假设，因为Full-1在表型上与Coch有许多相似之处。调节腋生花序分枝产生的豆荚数量的基因也将被描述。了解花序发育是如何调节的，有可能提高作物产量。

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.