Optimising the development of the energy grass Miscanthus through manipulation of flowering time

为了应对气候变化，有必要减少能源的使用，并用可再生能源取代更多的能源。此外，对进口化石燃料的过度依赖，将未来的燃料安全置于危险之中。存在许多可再生能源(例如，生物质、风能、太阳能、海洋)，人们普遍预测，在未来，没有一种形式将占主导地位，换句话说，将是一种混合能源经济。来自能源作物的生物质是可再生能源组合的重要组成部分，因为除了能够通过燃烧提供电力和热量外，生物质还可以用来制造石油替代品，如液体运输燃料和平台化学品。芒属是一种多年生草本植物，也是一种理想的能源作物，因为它结合了热带牧草(如甘蔗)的快速生长速度和对英国温度的耐受性。此外，它是一种非常环保的作物，因为它只在生长初期需要除草剂处理，每年产生高产量的生物量，对以前的营养生长产生复利，而且在年底进行高效的养分循环减少了种植和化肥投入。然而，由于芒属是一种新作物，以往的基础研究极其有限，对其生长发育的调控知之甚少。这项提案试图通过研究开花的分子基础来解决这一问题。为了帮助这一点，我们将利用为拟南芥、水稻和玉米等模式生物开发的技术和开花知识。之所以选择开花，是因为在芒属植物中，开花是最有可能在优化后迅速实现产量最大化的特性。例如，植物开花越晚越好，以增加生长季的长度，从而进行更长时间的光合作用，从而产生更多的生物量。然而，开花也会引发衰老，这是一个关键的过程，通过这个过程，氮素和其他资源被转移到根茎，即植物地下的一部分。这一点可能非常重要，因为一些植物成分，主要是钾和氯化物具有腐蚀性，或在燃烧时形成腐蚀性化合物，并对发电设备造成损害。芒属是一种商业栽培的芒属植物，是甘蔗芒属和中华芒属两个物种之间自然产生的杂交品种。然而，在亲本物种中，开花似乎受到不同的控制，当日照长度小于12小时时，甘蔗开花，而当经历足够温暖的日子时，芒花开花。这种杂交种在英国的条件下很少开花，而且是不育的。因此，在这个项目中，我们的目标是在芒属的两个亲本中找出与开花时间最有可能相关的基因。对模式生物的研究已经确定了40多个与开花时间有关的基因，芒属中的相同基因将被识别并测试其同等作用。这将使基于DNA的开花分子标记的开发成为可能，可以用于英国的芒属育种计划。分子标记的使用将有助于优化和预测幼苗的开花时间，而不是必须等待三年才能使植物成熟。这也将有助于新杂交亲本的选择。从该项目获得的信息将有助于更快地提高芒属植物的生物量产量。因此，这将意味着更多的碳将被固定在更小的土地面积上，此外，还将改善农业经济，减少对其他形式土地使用的压力，增强英国的燃料安全，最重要的是减少全球二氧化碳排放。

To combat climate change, it is necessary to use less energy and replace more of the energy we use with renewable sources. Furthermore, there is an over dependence on imported fossil fuels, putting future fuel security at risk. A number of renewable energy sources exist (for example, biomass, wind, solar, marine) and it is widely predicted that in the future no one form will dominate, in other words there will be a mixed energy economy. Biomass from energy crops are an important part of the renewable energy mix because in addition to being able to provide electricity and heat through combustion, biomass can be used to make petroleum replacements such as liquid transport fuels and platform chemicals. Miscanthus is a perennial grass and an ideal energy crop because it combines the fast growth rate of a tropical grass, such as sugarcane, with a tolerance to grow at UK temperatures. Furthermore it is a very 'eco-friendly' crop since it requires herbicide treatment only during initial establishment, produces a high yield of biomass annually with 'compound interest' on previous vegetative growth, and highly effective nutrient recycling at the end of the year reduces cultivation and fertiliser inputs. However as Miscanthus is a new crop, previous basic research has been extremely limited so that little is known about the regulation of growth and development. This proposal seeks to start addressing this deficit by investigating the molecular basis of flowering. To help in this we will exploit technologies developed for, and knowledge of flowering in, model organisms such as Arabidopsis thaliana, rice and maize. Flowering has been chosen because it is the characteristic identified as most likely, when optimised, to maximise yield quickly in Miscanthus. For example it is highly desirable for plants to flower as late as possible to increase the length of the growing season and therefore photosynthesise for longer to produce more biomass. However flowering is also desirable to trigger senescence which is a critical process by which nitrogen and other resources are mobilised to the rhizome, the part of the plant below ground. This can be very important because some plant constituents, principally potassium and chloride are corrosive or form corrosive compounds when combusted and cause damage to energy generation equipment. The commercially grown variety of Miscanthus (Miscanthus x giganteus), is a naturally occurring hybrid between two species, Miscanthus sacchariflorus and Miscanthus sinensis. However flowering appears to be controlled differently in the parent species so that Miscanthus sacchariflorus flowers when the daylength is less than 12 hours but Miscanthus sinensis flowers when sufficient warm days have been experienced. The hybrid only very rarely flowers under UK conditions and is sterile. Therefore in this project we aim to identify the genes most likely to be involved in flowering time in the two parents of Miscanthus x giganteus. Research on model organisms has identified over 40 genes implicated in flowering time and the equivalent genes in Miscanthus will be identified and tested for an equivalent role. This will enable the development of DNA-based molecular markers for flowering which can be used in the UK Miscanthus breeding programme. Use of molecular markers will help with the optimisation and prediction of flowering time in young plants rather than having to wait three years for plants to gain maturity. It will also help in the selection of parent plants for new crosses. The information gained from this project will help to increase biomass yields in Miscanthus more quickly. This will therefore mean that more carbon will be fixed in a smaller area of land, and in addition improve farm economics, decrease pressure on other forms of land use, increase UK fuel security and most importantly reduce global carbon dioxide emissions.