Interaction of auxin and strigolactone in the regulation of carpic dominance

背景植物繁殖过程中产生的种子是相互沟通的，并且在较老/较有活力的果实中的种子能够限制或中止新果实/种子的发育。驱动这一现象的机制（“果实优势”）的特点很差，但初步数据表明，植物激素独脚金内酯和生长素发挥关键作用。分析独脚金内酯和生长素在结实优势中的作用.确定导致结实优势的转录反应。定义环境信号，调节carpic优势在crop species.NoveltyAlthough的carpic优势的现象是长期公认的，很少的工作已经进行，特别是在分子遗传时代。因此，该项目代表了植物发育生物学的一个非常新颖的领域。及时性迫切需要提高作物产量，以养活不断增长的全球人口。因此，这个项目是非常及时的，因为结实优势是一个主要的限制结实，了解它可以解锁产量潜力的快速增加。实验方法为了确定独脚金内酯和生长素在结实优势的作用，我们将利用现有的分子遗传工具在模式植物拟南芥，包括生长素/独脚金内酯突变体和报告线。我们还将在作物番茄（具有很强的果实优势）中开发工具，以在果实发育过程中对生长素/独脚金内酯动态进行实时成像。我们将使用RNA-seq来识别在结实显性期间显性和显性果实/种子中发生的转录变化，然后使用反向遗传分析来测试所识别的候选基因在该现象中的作用。我们还将在作物油菜（拟南芥的近亲）中使用田间和温室实验，以确定调节结实优势程度的环境信号，并将拟南芥中产生的知识转移到田间/农业环境中。本项目旨在了解植物中形成结实优势现象的生化，遗传和细胞机制。因此，它深深植根于分子和细胞水平的机械生物学。该项目非常适合农业和粮食安全研究领域的职权范围。全球粮食安全将要求主要作物品种增加产量，而结实优势是许多这些品种产量的主要限制因素。如果我们能够理解结实优势的机制基础，我们就可以培育结实优势降低的作物品种，这可能导致产量的逐步变化，而不需要更密集的投入（例如肥料）。

BackgroundSeeds produced during plant reproduction are known to communicate with each other, and seeds in older/more vigorous fruits are able to limit or abort the development of new fruits/seeds. The mechanisms that drive this phenomenon ('carpic dominance') are poorly characterised, but preliminary data suggest the phytohormones strigolactone and auxin play key roles.Objectives1. Analyse the role of strigolactone and auxin in carpic dominance.2. Identify transcriptional responses that result in carpic dominance.3. Define environmental signals that modulate carpic dominance in crop species.NoveltyAlthough the phenomenon of carpic dominance is long-recognized, very little work has been undertaken, especially in the molecular genetic era. This project thus represents a highly novel area in plant developmental biology. TimelinessThere is a pressing need to increase crop yields to feed an expanding global population. This project is thus exceptionally timely, since carpic dominance is a major limit on seed set, and understanding it could unlock rapid increases in yield potential.Experimental ApproachTo define the role of strigolactone and auxin in carpic dominance, we will exploit existing molecular genetic tools in the model plant Arabidopsis, including auxin/strigolactone mutants and reporter lines. We will also develop tools in the crop plant tomato (which has strong carpic dominance) to perform live imaging of auxin/strigolactone dynamics during fruit development. We will use RNA-seq to identify transcriptional changes that occur in both dominant and dominated fruit/seeds during carpic dominance, and will then test the role of identified candidate genes in the phenomenon using reverse genetic analyses. We will also use both field and glasshouse experiments in the crop species oilseed rape (a close relative of Arabidopsis), to identify the environmental signals that modulate the extent of carpic dominance, and to transfer knowledge generated in Arabidopsis to field/agricultural contexts.This project aims to understand the biochemical, genetic and cellular mechanisms that form the basis of the carpic dominance phenomenon in plants. It is therefore deeply rooted in mechanistic biology at the molecular and cellular level. The project is an excellent fit with the remit of the agriculture and food security research area. Global food security will require increased yield from major crop species, and carpic dominance acts as a major limit on yield in many of these species. If we can understand the mechanistic basis of carpic dominance, we can breed crop species with reduced carpic dominance, which could result in a step-change in yield, without the need for more intensive inputs (e.g. fertilizer).