Evolution of floral organ reduction

花器官减少的进化

• 批准号: BB/H01313X/1
• 负责人: Angela Hay
• 金额: $ 54.76万
• 依托单位: University of Oxford
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2010
• 资助国家: 英国
• 起止时间: 2010 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FH01313X%2F1
• 关键词: Evolution; floral; organ; reduction

We aim to understand how different species evolve different physical features. Flowering plants have the greatest species number and diversity of any plant group on earth and petals played a critical role in generating this diversity by attracting different pollinators. Many plants can also pollinate themselves and this can be advantageous for weeds like hairy bittercress that invade new habitats. This transition to self-pollination can be associated with petal loss, however, the genetic mechanisms that determine petal number, and how these have varied during evolution, are poorly understood and are hence the focus of our research. Our research aims to understand the genetic changes that underlie changes in petal number between two mustard species, the model organism thale cress (Arabidopsis thaliana) and hairy bittercress (Cardamine hirsuta). These species are closely related and easy to work with in the lab, so genetic and transgenic experiments can be used to identify mechanisms that make these two species look different from each other. Thale cress has a typical mustard flower with four petals while hairy bittercress differs by having fewer petals. We know that one region of the hairy bittercress genome controls a large amount of the variation observed in petal number in this species. We also know that an important gene controlling petal development called LEAFY maps to this genomic region. In order to identify genes that repress petal number in hairy bittercress we induced variation in the genome by mutagenesis and identified mutants that convert hairy bittercress to thale cress petal number. Identifying the genes mutated in these plants will tell us which genes act to reduce petal number in hairy bittercress but not in thale cress. One way that LEAFY regulates petal development is by turning on expression of the APETALA1 gene. Other regulators in thale cress but not in hairy bittercress also turn on this gene. We want to know whether this difference in gene regulation plays a part in making these two species look different from each other. Here, we will determine whether LEAFY or a different gene controls the variation observed in hairy bittercress populations. We will also identify genes that act only in hairy bittercress to reduce petal number. Many of the genetic changes during evolution that produce different-looking species result from changes in the way genes are regulated and we will test whether this is true for the APETALA1 gene in these two mustard species. Thus, species-specific differences in petal number between hairy bittercress and thale cress, and natural variation in this trait between hairy bittercress populations around the world, provide an exciting experimental platform to trace evolution from specific changes in gene regulation through to altered morphologies in nature. Another group of mustards called Brassicas are remarkable for containing more important agricultural and horticultural crops than any other plant genus. Understanding the genetic basis of mustard diversity is therefore a vital part of generating crops for the 21st century.

我们的目标是了解不同物种如何进化出不同的物理特征。开花植物在地球上任何植物类群中拥有最多的物种数量和多样性，而花瓣通过吸引不同的传粉媒介在产生这种多样性方面发挥了关键作用。许多植物也可以自行授粉，这对于侵入新栖息地的杂草（如毛苦菜）来说是有利的。这种向自花授粉的转变可能与花瓣损失有关，然而，人们对决定花瓣数量的遗传机制以及它们在进化过程中如何变化知之甚少，因此是我们研究的重点。我们的研究旨在了解两种芥菜物种——模式生物拟南芥（Arabidopsis thaliana）和毛苦芥菜（Cardamine hirsuta）——花瓣数量变化背后的遗传变化。这些物种密切相关并且易于在实验室中使用，因此遗传和转基因实验可用于识别使这两个物种看起来彼此不同的机制。塔勒水芹具有典型的芥菜花，有四个花瓣，而毛苦菜的不同之处在于花瓣较少。我们知道，毛苦芥基因组的一个区域控制着该物种中观察到的花瓣数量的大量变异。我们还知道，控制花瓣发育的重要基因（称为 LEAFY）映射到该基因组区域。为了鉴定抑制毛苦菜花瓣数量的基因，我们通过诱变诱导基因组变异，并鉴定出将毛苦菜转化为拟南芥花瓣数量的突变体。识别这些植物中突变的基因将告诉我们哪些基因会减少毛苦菜的花瓣数量，但不会减少拟南芥的花瓣数量。 LEAFY 调节花瓣发育的一种方法是开启 APETALA1 基因的表达。拟南芥中的其他调节因子（但毛苦菜中没有）也激活该基因。我们想知道基因调控的差异是否导致这两个物种看起来彼此不同。在这里，我们将确定 LEAFY 或不同的基因是否控制在毛苦菜群体中观察到的变异。我们还将鉴定仅在毛苦芥中起作用以减少花瓣数量的基因。进化过程中产生外观不同的物种的许多基因变化都是由基因调节方式的变化造成的，我们将测试这两个芥菜物种的 APETALA1 基因是否如此。因此，毛苦芥和拟南芥花瓣数量的物种特异性差异，以及世界各地毛苦芥种群之间这一性状的自然变异，为追踪从基因调控的特定变化到自然界形态改变的进化提供了一个令人兴奋的实验平台。另一类称为芸苔属的芥菜因其含有比任何其他植物属更重要的农业和园艺作物而引人注目。因此，了解芥菜多样性的遗传基础是 21 世纪作物生产的重要组成部分。

项目成果

Morphomechanical Innovation Drives Explosive Seed Dispersal.

• DOI: 10.1016/j.cell.2016.05.002
• 发表时间: 2016-06-30
• 期刊: Cell
• 影响因子: 64.5
• 作者: Hofhuis H;Moulton D;Lessinnes T;Routier-Kierzkowska AL;Bomphrey RJ;Mosca G;Reinhardt H;Sarchet P;Gan X;Tsiantis M;Ventikos Y;Walker S;Goriely A;Smith R;Hay A
• 通讯作者: Hay A

The genetic architecture of petal number in Cardamine hirsuta.

毛碎米荠花瓣数量的遗传结构。

• DOI: 10.1111/nph.13586
• 发表时间: 2016
• 期刊: The New phytologist
• 作者: Pieper B