Genetic engineering approaches to enhance oil content in oilseed crops

Oilseed crops play an important role in the agricultural economy. Apart from being an integral component of human diet and industrial applications, they are also gaining importance as replacement to fossil fuels for meeting the energy needs. The last two decades have been marked by several important events in genetic engineering and identification of gene targets for enhancing seed oil content in oilseed crops, and will aid the successful development of new generation high yielding oil crops. Specifically, genetic engineering has shown real breakthrough in enhancing oil content in oilseed rape, camelina, soybean and maize. Moreover, ongoing research efforts to decipher the possibilities of genetic modifications of key regulators of oil accumulation along with physiological and biochemical studies to understand lipid biosynthesis will set a platform to produce transgenic oilseed crops with enhanced oil content. In this review, we briefly describe different genetic engineering approaches explored by different researchers for enhancing oil content. Further, we discuss a few promising and potential approaches and challenges for engineering oil content in oilseed crops.     

油料作物基因工程育种

日新月异的基因工程技术对现代育种学产生了深远的影响 ,特别是转基因油料作物在目前全球种植的转基因作物中占了很大比例 ,对油料作物的基因工程研究更是涉及了抗性育种、品质改良、杂种优势利用和分子农业等广泛的领域。概述了国际上油料作物基因工程研究和商品化应用的现状 ,举例介绍了我国在该领域中取得的主要进展。在综合分析我国该领域研究现状、存在问题和国际发展趋势基础上 ,提出了我国油料作物转基因研究及产业化的发展策略和取得重大进展的突破口 ,着重强调了油料作物基因工程与“生物柴油”战略的结合。     

生物柴油原料资源高油脂微藻的开发利用

生物柴油作为化石能源的替代燃料已在国际上得到广泛应用。至今生物柴油的原料主要来自油料植物, 但与农作物争地的情况以及较高的原料成本限制了生物柴油的进一步推广。微藻作为高光合生物有其特殊的原料成本优势, 微藻的脂类含量最高可达细胞干重的80%。利用生物技术改良微藻, 获得的高油脂基因工程微藻经规模养殖, 可大大降低生物柴油原料成本。介绍了国内外生物柴油的应用现状, 阐述了微藻作为生物柴油原料的优势, 对基因工程技术调控微藻脂类代谢途径的研究进展, 以及在构建工程微藻中面临的问题和应采取的对策进行了综述和展望。     

基因工程在改善植物油营养价值中的应用

本文介绍了近年来应用基因工程技术对植物油的脂肪酸成分进行改造, 进而生产有益于健康的食用油所取得的进展。近10年来, 应用基因修饰的方法对植物油进行营养学方面的改良已经取得了很大的进展, 随着植物脂肪酸生物合成途径的日趋明确, 通过转基因技术可以让植物生产许多含有特殊脂肪酸成分且对人类健康有益的植物油。     

基因工程在改善植物油营养价值中的应用

本文介绍了近年来应用基因工程技术对植物油的脂肪酸成分进行改造,进而生产有益于健康的食用油所取得的进展.近10年来,应用基因修饰的方法对植物油进行营养学方面的改良已经取得了很大的进展,随着植物脂肪酸生物合成途径的日趋明确,通过转基因技术可以让植物生产许多含有特殊脂肪酸成分且对人类健康有益的植物油.     

Achievements and problems of genetic engineering of Crucifereceae plants

Plants of the Brassicaceae family are important oil, vegetable and feed crops. The review is devoted to the latest achievements in genetic engineering of plants from this family. Results concerning development of effective methods both of Agrobacteium-mediated transformation and of direct gene uptake are considered. Particularly, possibilities of plant genetic modification with the aim to improve agronomically and commercially important traits are stressed. Problems of biologically safe introduction of transgenic plants into agricultural production are discussed.     

经遗传修饰生物体的研究进展及其释放后对环境的影响

８０年代以来,以基因工程为代表的生物技术突飞猛进。转移不同性状的转基因作物在美国被批准进入大田试验的有４０个以上的作物,包括小麦、玉米和水稻等４种谷类粮食作物,主要的纤维作物棉花,蔬菜种类１０种以上,水果９种,其它还有油料作物,牧草和花卉等。到１９９６年６月已被批准进入市场的已有１８种,还有一批有待批准商业化。今年２月,美国农业部已第一次批准一种喂饲其它螨的转基因螨进入大田试验。第一个转基因线虫也正在申请向环境释放。已至少有２５个发展中国家,１０个以上作物转基因成功,ＧＭＯｓ作大田释放的总数在１６０次以上。基因工程能带来巨大的经济效益和社会效益。但是有不少数量的科学家或如“有关科学家联盟”等一些非政府组织指出基因工程的产物向环境释放会可能带来生态或环境危险。发达国家中,美国与欧洲国家的政府对ＧＭＯｓ批准释放的态度也是一样的,后者要比前者慎重得多。最近丹麦科学家已证实转基因油菜中的抗除草剂基因已经转入杂草中;由美国一种子公司开发的转基因大豆被证实对人体过敏而其产品决定不向市场投放。要有充分的科学实验,自然科学家与社会科学家相结合,对经遗传修饰生物体可能带来巨大经济效益和造成环境或生态危机进行充分的评估。在这基础上作出权衡,供政府决策者能作出正确的决策。这不仅在中国而是在全世界范围内已到了一个关键时刻。因此,生物安全问题是每次《生物多样性公约》缔约国会议的主要讨论议题。     

Genetic Engineering of Energy Crops: A Strategy for Biofuel Production in China Free Access

Biomass utilization is increasingly considered as a practical way for sustainable energy supply and long‐term environment care around the world. In concerns with food security in China, starch or sugar‐based bioethanol and edible‐oil‐derived biodiesel are harshly restricted for large scale production. However, conversion of lignocellulosic residues from food crops is a potential alternative. Because of its recalcitrance, current biomass process is unacceptably expensive, but genetic breeding of energy crops is a promising solution. To meet the need, energy crops are defined with a high yield for both food and biofuel purposes. In this review, main grasses (rice, wheat, maize, sorghum and miscanthus) are evaluated for high biomass production, the principles are discussed on modification of plant cell walls that lead to efficient biomass degradation and conversion, and the related biotechnologies are proposed in terms of energy crop selection.     

The application of genetic engineering to oilseed crops

Increasing attention is being given to the prospects for the genetic engineering of oilseed crops, both in the industrial and academic sectors. The process of creating genetically stable new crops with desirable vegetable oil composition and content is necessarily complex. The modification of seed storage lipids appears to be feasible and there exists a broad knowledge base on lipid biosynthetic enzymes, but applied research and product development will depend on gaining a better understanding of the biochemical bases of lipid biosynthesis.     

植物脂肪酸代谢途径遗传调控的研究进展

目前,利用传统育种方法改良油料作物脂肪酸组分已取得巨大成功,通过有性杂交、X-射线或EMS处理等方法都可用来修饰存在于油菜中脂肪酸的性质。国外已培育出高棕榈酸、高或低亚油酸、高油酸和无芥酸的油菜品种。但由于油料作物基因池(Gene Pool)的局限性使得育种学家不得不寻找其他种质资源。随着基因克隆和遗传转化技术的进步,通过基因工程改良油料作物品质已成可能。本文主要介绍了植物脂肪酸的代谢途径以及通过操纵TAG的生物合成来改变油的成分等研究,其中主要包括脂肪酸链长度的改良、饱和度改良、增加脂肪酸含量以及新的不饱和脂肪酸的改良等方面。不久的将来,转基因油料作物中将会产生更有价值的脂肪酸造福于人类。     

In-depth genome diversity,population structure and linkage disequilibrium analysis of worldwide diverse safflower (Carthamus tinctorius L.) accessions using NGS data generated by DArTseq technology

Molecular Biology Reports - Safflower (Carthamus tinctorius L.) is one of the most important oilseed crops for its seed oil rich in unsaturated fatty acids. Precise utilization of diverse genetic...     

Advances in development of transgenic pulse crops

It is three decades since the first transgenic pulse crop has been developed. Todate, genetic transformation has been reported in all the major pulse crops like Vigna species, Cicer arietinum, Cajanus cajan, Phaseolus spp, Lupinus spp, Vicia spp and Pisum sativum, but transgenic pulse crops have not yet been commercially released. Despite the crucial role played by pulse crops in tropical agriculture, transgenic pulse crops have not moved out from laboratories to large farm lands compared to their counterparts - 'cereals' and the closely related leguminous oil crop - 'soybean'. The reason for lack of commercialization of transgenic pulse crops can be attributed to the difficulty in developing transgenics with reproducibility, which in turn is due to lack of competent totipotent cells for transformation, long periods required for developing transgenics and lack of coordinated research efforts by the scientific community and long term funding. With optimization of various factors which influence genetic transformation of pulse crops, it will be possible to develop transgenic plants in this important group of crop species with more precision and reproducibility. A translation of knowledge from information available in genomics and functional genomics in model legumes like Medicago truncatula and Lotus japonicus relating to factors which contribute to enhancing crop yield and ameliorate the negative consequences of biotic and abiotic stress factors may provide novel insights for genetic manipulation to improve the productivity of pulse crops.     

抗虫基因研究及在芸薹属作物上的应用

芸薹属作物属十字花科,包括多种重要的蔬菜和油料作物。该类作物易受病虫害侵袭,造成品质和产量严重受损。化学方法防治害虫不仅破坏环境而且费用昂贵,所以培育抗虫品种成为既经济又环保的措施之一。但由于目前抗虫资源匮乏,难以通过常规育种培育出抗虫的品种,植物基因工程技术的应用,能加快育种进程,提高育种效率。简要介绍近年来抗虫基因的发掘及其在芸薹属中的应用进展。     

大豆种子蛋白和油脂含量调控的研究进展

作为重要的粮油饲兼用作物,大豆为世界膳食提供高达约71%的蛋白质和29%的油脂。随着人口不断增长和大豆消费需求的不断提高,在有限的耕地面积和单产条件下,大豆品质的遗传改良则更具重要意义。该文综述了大豆种子蛋白和油脂含量两个重要品质性状调控的研究进展,总结了调控大豆蛋白和油脂合成的关键酶和转录因子及因子间的相互作用,并根据蛋白和油脂合成代谢调控途径中关键酶和转录因子作用机制,绘制了大豆蛋白和油脂合成代谢的分子调控网络。此外,该文还讨论了当前大豆种子蛋白油脂含量调控研究存在的瓶颈及对策,以期为大豆种子品质的遗传改良和高产品种培育提供参考。     

Molecular breeding strategies for the modification of lipid composition

Summary Lipids are key components of all living cells. Acyl lipids and sterols provide the matrix of the biological membranes that both define the boundaries of cells and organelles, and act as sites for the trafficking of molecules within and into/out of cells. Lipids are also important metabolic intermediates and the most efficient form of energy storage that is available to a cell. It is the latter, energy-storing function that is of most relevance to this review. Storage lipids are accumulated in abundance in many of our most important crops, including maize, soybean, rapeseed, and oil palm, giving rise to a commerical sector valued at over $50 billion/year. Because the storage lipids of the major global oil crops have a relatively restricted composition, there is great interest in using all available breeding technologies, whether traditional or modern, to enhance the variation in lipid quality in existing crops and/or to domesticate new crops that already accumulate useful novel lipids. Over the past few decades, there has been a great deal of effort to manipulate fatty acid composition in order to produce novel lipids, especially for industrial applications. However, these attempts, many based on genetic engineering, have met with only limited commercial success-to date. More recently, there has been a resurgence of interest in the modification of both acyl and non-acyl lipids to enhance the nutritional quality of plant oils. In this review, we will examine the background to plant lipid modification and some of the latest developments, with a particular focus on edible oils.     

油菜高含油量基因工程研究

油菜是世界上重要油料作物之一,是世界食用植物油的重要来源。近十年来,随着其种植面积的不断扩大,目前已成为世界第二大植物油来源,因此提高油菜种子含油量具有重大的经济利用价值。近年来,基因工程技术的飞速发展带来了优化油菜品种资源的新方法。三酰甘油对种子油脂的形成十分重要,它是油菜种子最主要的储藏脂类。将三酰甘油合成代谢途径中的关键酶基因及一些转录因子转入到油菜组基因中,一方面增加种子中关键酶基因的表达;另一方面增加转录因子表达以增强糖酵解和三酰甘油形成的相关基因表达,增加底物浓度和三酰甘油合成的速度,期待获得高含油量的转基因油菜。本文综述了国内外关于油菜油酯代谢关键酶基因及调控基因的研究进展,并展望了未来提高油菜含油量的发展思路。     

世界特种油料种质资源保存概况

为加强特种油料种质资源的收集保存,更好地为育种研究利用提供服务,本文阐述了特种油料种质资源在我国及世界上重点国家的保存情况.美国、印度、欧盟、中国等13个国家共保存向日葵、红花、亚麻(含纤用)、蓖麻及苏子等特种油料种质资源约9万份,其中亚麻30000多份,向日葵21800多份,红花15000多份,蓖麻约5000多份,苏子近900份.欧盟、美国、俄罗斯和加拿大是亚麻资源的主要保存国家(地区);向日葵资源主要集中在美国、欧盟和中国;红花种质主要分布在印度、美国、中国和俄罗斯;蓖麻种质以中国、美国和印度居多.比较这些国家所拥有的特种油料种质资源数量,美国位居第一,保存数量最多,超过22000份;印度其次;欧盟、中国和俄罗斯居中.中国保存特油作物种质资源(蓖麻、向日葵、红花、苏子)8400余份,其中21%为国外种质,国内种质主要来源于湖北省、华北、东北、西北和西南地区.本文为我国特种油料种质资源的引进、收集保存提出了建议.     

Biodiesel from microalgae

Continued use of petroleum sourced fuels is now widely recognized as unsustainable because of depleting supplies and the contribution of these fuels to the accumulation of carbon dioxide in the environment. Renewable, carbon neutral, transport fuels are necessary for environmental and economic sustainability. Biodiesel derived from oil crops is a potential renewable and carbon neutral alternative to petroleum fuels. Unfortunately, biodiesel from oil crops, waste cooking oil and animal fat cannot realistically satisfy even a small fraction of the existing demand for transport fuels. As demonstrated here, microalgae appear to be the only source of renewable biodiesel that is capable of meeting the global demand for transport fuels. Like plants, microalgae use sunlight to produce oils but they do so more efficiently than crop plants. Oil productivity of many microalgae greatly exceeds the oil productivity of the best producing oil crops. Approaches for making microalgal biodiesel economically competitive with petrodiesel are discussed.     

花生抗病基因分离克隆研究进展

花生是重要的油料作物和经济作物。近年来多种病害严重威胁着花生产业的发展,筛选花生抗病基因并对其进行研究成为花生抗性育种的新热点。结合抗病基因分离克隆在花生育种工作和遗传研究等领域逐渐显现的广阔前景,我们简要综述了国内外花生抗病基因分离克隆的研究现状,介绍了抗病基因分离克隆的类型及特点,并探讨了今后的研究方向。     

我国6种主要木本油料作物的研究进展

选择我国3种传统木本油料作物油茶(Camellia oleifera)、核桃(Juglans regia)和文冠果(Xanthoceras sorbifolium)以及3种新兴木本油料作物油用牡丹(Paeonia suffruticosa)、星油藤(Plukenetia volubilis)和元宝枫(Acer truncatum), 从种质资源概况、脂肪酸组成、活性成分以及油脂合成代谢的分子生物学等方面进行了详细综述。文章旨在引导国内生产者因地制宜地种植木本油料作物, 从而发挥木本植物油的优势, 补充草本油料供给不足。同时, 在资源保护的前提下, 增加我国植物油供给量, 丰富人们的营养来源和提高健康水平。该文还分析了我国木本油料作物利用中存在的问题, 为进一步开发利用木本油料作物指明了研究方向。