The ABC of fruit-shape formation in the Brassicaceae

尽管植物器官的形状千差万别，但共同的原则可能是形状确定的基础。从遗传学的早期就已经认识到，可以区分调节形状的基因活动和只影响大小的基因活动。最近，决定番茄、甜瓜和辣椒等驯化果树形状的关键遗传因素已被发现。此外，叶片和花瓣生长的组织水平模型导致了形状取决于由极性场定向的各向异性生长模式。我们最近扩展了这些研究，证明这样的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时期进化，并迅速在陆地上定居。它们成功的一个主要原因是形成了保护和培育发育中的种子的果实。此外，在相对较短的时间内，果实形状出现了大量的多样性，这使得开发出巧妙的受精方法以及有效传播种子的策略。十字花科植物包含丰富的果实形态多样性，包括一些我们的遗传特征最好的模式植物和重要的作物物种。因此，十字花科提供了一组理想的植物来研究特定形状是如何形成的。虽然在模式植物拟南芥中已经鉴定了许多控制果实模式的基因，但导致特定心皮和果实形态的过程仍然知之甚少。为了揭开这些过程，我们需要比较不同形状水果的生长和形态发育。在这个项目中，我们将研究十字花科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观察到的十字花科物种之间某些水果形状的变化。我们将扩大这些研究，将果实形状高度多样化的非模式植物包括在内。除了对器官生长的基本了解外，这个项目的结果应该有助于确定如何应用形状和生长知识来提高油菜产量的策略。更广泛地说，了解器官形状决定的机制对从医学到作物改良的不同学科都有影响。

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.