RUI: Regulation of Inflorescence Architecture in Pea

在自然和农业环境中，花序结构，繁殖分支的模式，影响果实和种子的产量。建筑模式的多样性与基本开花基因的高度保守性形成鲜明对比，为发育和进化生物学家提供了一个有趣的难题。花序发育有多种途径。对具有不同花序类型的几种模式系统进行深入的比较分析，将有助于了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（Pisum sativum）是比较分析花序发育的一个很好的模型系统，因为它的花序（复合总状花序与简单总状花序）比广泛研究的拟南芥（Arabidopsis）和抗鼻草（Antirrhinum）系统复杂一步。此外，拟南芥（Arabidopsis）和牛头花（Antirrhinum）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 [proliferative花序分生组织（pim-1）]。突变型与其他系统中的表型相似，但对植物的整体结构有不同的影响。十个基因已被确定在花序的特定区域起主要作用。我们将建立一个模型来解释这些基因如何与自身、环境以及通过产生或控制花抑制剂和花启动子的运输来调节开花时间的基因相互作用。调控花序发育的两个基因将被研究。COCHLEATA （COCH）突变体影响营养和生殖生长。在被研究的四种辅酶等位基因中，托叶对大小和形状的微妙不对称大大增强。这导致了“前后”不对称，这与叶片螺旋状初始化的模型不一致。COCH是一个移植物传播因子。嫁接到教练突变体上的野生型接穗会产生与突变体相似的异常花朵。萼片数变化，次生花通常在第一个萼片的腋部形成。双突变体coch pim-1不开花，这表明有两个部分冗余的开花途径。本文将从以下几个方面分析COCH在调节茎结构中的作用：1)发育形态学研究；2)嫁接和组织培养实验；3) coch与其他开花突变体及环境因子的相互作用研究；4)对coch和coch植物的托叶和萼片进行遗传和组织学比较，以评估叶片和萼片的关系；5)对教练组PFLO和PSQUA表达谱的研究；6)验证COCH是拟南芥中FRUITFULL （full -1）同源基因的假设，因为full -1与COCH具有许多表型相似性。调节腋生花序分支产生的豆荚数量的基因也将被表征。了解花序发育是如何被调控的，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.