The ABC of fruit-shape formation in the Brassicaceae

尽管植物器官的形状有很大的差异，但形状决定的基础可能是共同的原则。从遗传学的早期开始，人们就认识到有可能区分调节形状的基因活动和只影响大小的基因活动。最近，一些决定番茄、甜瓜和辣椒等家养水果作物形状的关键遗传因素已经被发现。此外，叶片和花瓣生长的组织水平模型表明，形状取决于极性场导向的各向异性生长模式。我们最近扩展了这些研究，证明这些模型也可以解释三维水果形状的生长模式和多样性。被子植物（开花植物）在1亿多年前的白垩纪进化，并迅速占领了陆地栖息地。他们成功的一个主要原因是果实的形成保护和滋养了正在发育的种子。此外，在相对较短的时间内，水果形状出现了大量的多样性，这使得巧妙的施肥方式和有效的种子传播策略得以发展。十字花科在果实形态上具有丰富的多样性，包括一些我们遗传上最具特征的模式植物和重要的作物物种。因此，十字花科提供了一个理想的植物群来研究特定的形状是如何建立的。虽然已经确定了许多控制模式植物拟南芥果实模式的基因，但导致特定心皮和果实形态的过程仍然知之甚少。为了揭示这些过程，我们需要比较不同形状果实的生长和形态发育。在本项目中，我们将研究十字花科植物果实形状形成的分子和遗传机制。我们将使用计算模型结合发育生物学和遗传学来帮助理解这种多样性。我们最近发现，基于实验数据的计算模型的简单调制可以解释在芸苔科物种中观察到的某些果实形状的变化。我们将扩大这些研究，包括具有高度多样化果实形状的非模式植物。除了对器官生长的基本理解之外，这个项目的结果应该有助于确定如何将形状和生长的知识应用于提高油菜产量的策略。更一般地说，了解器官形状决定的机制对从医学到作物改良的各种学科都有影响。

Despite the great diversity in plant organ shapes, common principles may underlie shape determination. It has been recognised from the early days of genetics that it is possible to differentiate between gene activities that regulate shape and those that only affect size. Recently, key genetic factors involved in determining shape in domesticated fruit crops such as tomato, melon and pepper have been uncovered. Furthermore, tissue-level models of leaf and petal growth have led to the suggestion that shape depends on patterns of anisotropic growth oriented by a polarity field. We have recently extended these studies by demonstrating that such models also can account for the growth patterns and diversity of three-dimensional fruit shapes. Angiosperms (flowering plants) evolved during the Cretaceous Period more than 100 million years ago and quickly colonised terrestrial habitats. A major reason for their success was the formation of fruits that protect and nurture the developing seeds. Moreover, a massive range of diversity in fruit shape arose during a relatively short time, which allowed for the development of ingenious ways of fertilisation as well as strategies for efficient seed dispersal. The Brassicaceae family contains a wealth of diversity in fruit morphologies and includes some of our genetically best characterised model plants and important crop species. Thus, the Brassicaceae family provides an ideal group of plants to study how specific shapes are established. Although many genes controlling fruit patterning in the model plant Arabidopsis thaliana have been identified, processes leading to specific carpel and fruit morphologies are still poorly understood. To unravel these processes, we need to compare the growth and morphological development of differently-shaped fruits. In this project, we will study the molecular and genetic mechanisms that underlie the formation of fruit shape within the Brassicaceae. We will use computational modelling combined with developmental biology and genetics to help understand this diversity. We recently found that simple modulations of a computational model based on experimental data can account for the observed variety of certain fruit shapes among Brassicaceae species. We will expand these studies and include non-model plants with highly diverse fruit shapes. Beyond the fundamental understanding of organ growth, results from this project should help identify strategies for how knowledge of shape and growth can be applied to increase yield of oilseed rape. More generally, understanding the mechanisms underlying organ-shape determination has implications for diverse disciplines ranging from medicine to crop improvement.