The validation, characterisation and translation of outputs derived from network analysis and QTL mapping of tomato fruit quality traits (TomNET)

番茄（Solanum lycopersicum）是世界上消费量最大的水果作物，年产量为1.5亿吨。西红柿是高价值产品，2009年的年产值约为320亿美元，包括加工和新鲜产品。它们是健康饮食的主要组成部分，提供维生素a、C、E和K的现成来源，矿物质包括K和Fe，以及亲脂抗氧化剂番茄红素（成熟番茄果实特有的红色色素）。现在有大量的科学证据可以证实，食用水果和蔬菜对人体健康有益。这些益处归因于食物基质中存在促进健康的植物化学物质或“生物活性物质”。尤其是在西方社会，挑战在于向消费者提供味道更好、营养更丰富的西红柿和其他水果，这些水果的保质期更长，而且价格对大多数消费者来说都是负担得起的。番茄最重要的品质特征是色泽、质地、风味和营养成分。质地也会影响味道，营养物质的释放，也许最重要的是保质期。在英国，据估计，40%的食物浪费是未食用的水果和蔬菜。除了其经济和社会作用外，番茄已成为了解肉质果实作物发育和成熟的良好科学模型，有强有力的证据表明，许多控制成熟的基因网络在不同的分类群中都是保守的。在水果作物中，品质性状的关键控制因素是成熟过程。TomNET项目的目标是提供更优质的番茄果实。我们的方法将整合系统分析和定量遗传研究，以识别和调节调节基因，从而精确控制果实发育和成熟过程。通过利用番茄野生物种变异，我们可以与先正达合作，将这些科学发现转化为商业实践；我们在LINK项目中的工业合作伙伴。该项目将以若干重要资源和发现为基础。首先，一个全面描述果实发育和成熟过程中基因转录物相互作用的调控网络。利用计算方法确定了成熟过程的假定调节因子。我们已经证明其中一种调节剂可以改善番茄果实的颜色。同时，与风味有关的化合物负责良好的口感水果产品增加。在这个项目中，我们将使用基因网络来确定其他的成熟调节因子，这些调节因子显示出改变关键果实品质性状的潜力。对于被称为高色素-4 （HP4）的转录激活因子，我们已经证实它是成熟相关性状的重要调节剂，将在多个调控水平上进行详细表征，以确定基因产物发挥其作用并影响成熟过程的潜在机制。这个项目的另一个关键基础是鉴定一个复杂的质地QTL背后的基因。在目标区域内，已经确定了几个相互作用的组件。本项目将利用稳定的转基因株系来阐明这些成分之间的功能和相互作用。还将尝试结合增强的颜色和纹理特征。最后，利用自然变异将这些特征转化为商业精英背景，从而将科学发现转化为商业实践。

Tomato (Solanum lycopersicum) is the most important fruit crop in the world by volume consumed, with annual production of 150 million metric tons. Tomatoes are high value products with an annual value in 2009 of around 32 billion US dollars covering both processed and fresh products. They are a major component of healthy diets and provide ready sources of vitamins A, C, E and K, minerals including K and Fe and the lipophilic antioxidant lycopene (the pigment responsible for the characteristic red colour of ripe tomato fruit). There is a wealth of scientific evidence that now exists to corroborate that the consumption of fruits and vegetables is beneficial to human health. These benefits have been attributed to the presence of health promoting phytochemicals or "bioactives" in the food matrix. The challenge, particularly, in Western societies, is to deliver to the consumer better tasting, more nutritious tomatoes and other fruit which have a prolonged shelf-life at a cost affordable to the majority of consumers. The most important quality traits in tomato are colour, texture, flavour and nutritional content. Texture can also impact on taste, the release of nutrients and perhaps most importantly shelf-life. In the UK it is estimated that 40% of the food waste is uneaten fruits and vegetables. In addition to its economic and societal role, tomato has become a well established scientific model for understanding the development and ripening of fleshy fruit bearing crops, with strong evidence that many of the gene networks controlling ripening have been conserved across different taxa. In fruit crops, the key controller of quality traits is the process of ripening. The aim of TomNET project is to deliver better quality tomato fruit. Our approach will integrate systems analysis and quantitative genetic studies to identify and modulate regulatory genes that allow precise control of fruit development and the ripening process. By harnessing tomato wild-species variation, we can deliver these scientific discoveries into commercial practice in collaboration with Syngenta; our industrial partner in this LINK project. The project will build on several important resources and findings. Firstly a regulatory network holistically describing the interaction of gene transcripts during fruit development and ripening. Using computational approaches putative regulators of the ripening process have been identified. We have shown that one of these regulators can improve tomato fruit colour. Simultaneously, flavour related compounds responsible for good tasting fruit products are increased. In this project we will use the gene networks to identify additional regulators of ripening that display the potential to alter key fruit quality traits. For the transcriptional activator termed high pigment-4 (HP4), which we have validated as an important modulator of ripening related traits, detail characterisation at multiple levels of regulation will be carried out to ascertain the underlying mechanisms by which the gene product can exert its effects and influence the ripening process. The other key foundation of this project is the identification of genes underlying a complex QTL for texture. Within the target region several interacting components have been identified. In the project the function and interaction between these components will be elucidated by using stable transgenic lines. Combining the enhanced colour and texture traits will also be attempted. Finally natural variation will be exploited to deliver these traits into commercial elite backgrounds thus translating science discovery through to commercial practice.