Targeting virus transmission in a vital crop for African food security

针对非洲粮食安全重要作物中的病毒传播

• 批准号: BB/P023223/1
• 负责人: John Carr
• 金额: $ 76.74万
• 依托单位: University of Cambridge
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2017
• 资助国家: 英国
• 起止时间: 2017 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FP023223%2F1
• 关键词: Targeting; virus; transmission; vital; crop

In East and Central Africa beans are a vital crop that naturally enriches the soil with nitrogen, providing natural fertilizer for other important crops such as maize and cassava. In the regional diet beans are important because they are rich in protein and critically important micronutrients. Since beans are mostly grown and traded by women, this crop provides important direct economic benefits to families & children. Unfortunately, a number of viruses attack bean plants, causing severe crop losses from disease.Although some bean varieties have resistance to one of these viruses, bean common mosaic virus, a closely related virus that occurs widely in sub-Saharan Africa (bean common necrotic mosaic virus) causes plants of these 'resistant' lines to die. Thus, many farmers prefer to plant susceptible bean lines despite the risk of crop loss and it is important to develop new strategies to defend this vital crop.The viruses are transmitted on the needle-like mouthparts of aphids. Importantly, the virus particles are lost by the aphid as soon as it feeds on a healthy plant; a weak link in the infection chain that we can exploit. Aphids are attracted to volatile chemicals released by plants. Virus infection can change these plants 'odours' so that aphids are encouraged to land on infected plants, acquire virus particles and then transport them to healthy plants. However, some bean varieties emit odours that are more attractive to aphids even when the plants are healthy. This means that if we plant mixtures of bean plants that include 'attractive' varieties we could decoy aphids away from the rest of the crop and slow disease transmission.Even better, if we can decoy virus-bearing aphids to land on plants that are resistant to the virus, then as soon as the aphid feeds it will lose the virus particles. This would effectively 'sanitize' the aphids and stop them spreading the virus, as well as dumping the virus into plants in which it cannot grow. An additional benefit of using a mixture containing a limited number of resistant plants is that viruses will be under less pressure to evolve new strains that can overcome resistance and, in cases where virus infection kills resistant plants, only a small proportion of the crop will be lost. Since aphids and related insects transmit the majority of plant viruses the method could be applied to a wide range of crops. Experiments under controlled conditions using varieties of a plant called Arabidopsis and an aphid transmitted virus called cucumber mosaic virus showed that aphid and virus spread can be altered using combinations of plants with different levels of attractiveness to aphids. A pilot field experiment in Uganda using mixtures of bean varieties with different degrees of attractiveness to aphids showed that aphids can be detained on more attractive varieties and inhibited from moving to other plants until close to harvest time, showing that our approach can work under farm conditions. Our multinational team will:A. Screen bean varieties that are popular in bean-growing regions in Kenya & Rwanda with respect to their attractiveness to aphids. We will identify the chemical odours emitted by plants that are most attractive to aphids. It is important to work with local varieties since farmers prefer certain bean types for hardiness under local conditions, cooking properties and local marketability. We will focus particularly on identifying aphid-attractive varieties carrying one or more virus resistance genes. B. Mathematically model the consequences of different arrangements and mixtures of attractive/repellent/susceptible/resistant plant lines on aphid and virus spread in fields. This will not only help us design our field and lab experiments but also to analyze the data we obtain. C. Test our models and lab experiments in Kenya & Rwanda to devise the most effective & practical field designs that minimize crop losses due to viral diseases.

在东非和中非，豆类是一种重要的作物，可以自然地使土壤富含氮素，为玉米和木薯等其他重要作物提供天然肥料。在该地区的饮食中，豆类很重要，因为它们含有丰富的蛋白质和至关重要的微量营养素。由于豆类大多由女性种植和交易，这种作物为家庭和儿童提供了重要的直接经济利益。不幸的是，许多病毒攻击豆类植物，造成严重的作物损失。尽管一些豆类品种对其中一种病毒有抗性，但菜豆普通花叶病毒是一种广泛存在于撒哈拉以南非洲的密切相关病毒(菜豆普通坏死性花叶病毒)，会导致这些抗病品系的植物死亡。因此，尽管面临作物损失的风险，许多农民还是喜欢种植敏感的豆类品系，因此开发新的策略来保护这种至关重要的作物是很重要的。这些病毒通过蚜虫针状的口器传播。重要的是，蚜虫一吃到健康的植物就会丢失病毒颗粒，这是感染链中的一个薄弱环节，我们可以加以利用。蚜虫被植物释放的挥发性化学物质所吸引。病毒感染可以改变这些植物的“气味”，从而鼓励蚜虫降落在受感染的植物上，获得病毒颗粒，然后将它们运送到健康的植物上。然而，一些豆类品种即使在植物健康的情况下也会散发出对蚜虫更具吸引力的气味。这意味着，如果我们种植的豆类植物中含有诱人的品种，我们就可以诱骗蚜虫远离其他作物，减缓疾病的传播。更好的是，如果我们能诱骗携带病毒的蚜虫降落在抗病毒的植物上，那么一旦蚜虫取食，它就会失去病毒颗粒。这将有效地“消毒”蚜虫，阻止它们传播病毒，并将病毒倾倒在不能生长的植物中。使用含有有限数量抗病植物的混合物的另一个好处是，病毒将面临较小的压力，进化出能够克服抗药性的新菌株，而且在病毒感染导致抗病植物死亡的情况下，只会损失一小部分作物。由于蚜虫和相关昆虫传播了大部分植物病毒，该方法可以应用于广泛的作物。在受控条件下进行的实验使用了一种名为拟南芥的植物和一种名为黄瓜花叶病毒的蚜传病毒的品种，实验表明，通过组合对蚜虫具有不同程度吸引力的植物，可以改变蚜虫和病毒的传播。在乌干达进行的一项试点田间试验表明，在接近收获季节之前，可以将不同种类的菜豆品种滞留在更有吸引力的品种上，并阻止它们转移到其他植物上，这表明我们的方法在农场条件下可以奏效。我们的跨国团队将：a.筛选在肯尼亚和卢旺达的豆类种植区受欢迎的豆类品种，以了解它们对蚜虫的吸引力。我们会找出最能吸引蚜虫的植物发出的化学气味。使用当地品种很重要，因为农民更喜欢某些类型的豆类，因为它们在当地条件下的抗逆性、烹饪特性和当地的适销性。我们将特别专注于鉴定携带一个或多个病毒抗性基因的吸引蚜虫的品种。B.对诱人/驱避/敏感/抗性植物品系的不同排列和混合对田间蚜虫和病毒传播的影响进行数学模拟。这不仅将帮助我们设计我们的野外和实验室实验，而且还将有助于分析我们获得的数据。C.在肯尼亚和卢旺达测试我们的模型和实验室实验，以设计出最有效和最实用的田间设计，将病毒疾病造成的作物损失降至最低。

项目成果

Complete Genome Sequence of a New Chickpea Chlorotic Dwarf Virus Strain Isolated from Tomato in Kenya, Obtained from Illumina Sequencing

• DOI: 10.1128/mra.01344-19
• 发表时间: 2020-01-01
• 期刊: MICROBIOLOGY RESOURCE ANNOUNCEMENTS
• 影响因子: 0.8
• 作者: Avedi, E. K.;Kilalo, C. D.;Mutuku, J. M.
• 通讯作者: Mutuku, J. M.

The Effects of Cucumber Mosaic Virus and Its 2a and 2b Proteins on Interactions of Tomato Plants with the Aphid Vectors Myzus persicae and Macrosiphum euphorbiae.

• DOI: 10.3390/v14081703
• 发表时间: 2022-08-01
• 期刊: Viruses

Susceptibility of five cabbage varieties to attack by aphids (Hemiptera: Aphididae) in the Accra plains of Ghana

加纳阿克拉平原五个卷心菜品种对蚜虫（半翅目：蚜科）侵袭的易感性

• DOI: 10.1007/s12600-020-00863-y
• 发表时间: 2021
• 期刊: Phytoparasitica
• 影响因子: 1.4
• 作者: Adenka K

Induction of aphid resistance in tobacco by the cucumber mosaic virus CMV?2b mutant is jasmonate-dependent

黄瓜花叶病毒 CMV?2b 突变体对烟草中蚜虫抗性的诱导是茉莉酸依赖性的

• DOI: 10.17863/cam.93846
• 发表时间: 2023
• 作者: Arinaitwe W