Engineering myxobacterial super-predators to fight crop disease

工程化粘细菌超级捕食者来对抗作物疾病

• 批准号: 2753764
• 金额: --
• 依托单位: Aberystwyth University
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2753764
• 关键词: Engineering; myxobacterial; super; predators; fight

Plant pathogenic microbes (phytopathogens) cause huge economic losses and threaten food security globally. For example, Ralstonia solanacearum alone causes more than $1 billion worth of potato crop losses each year in just the USA. To reduce pre-harvest wastage and increase food security, there is an urgent need to fight crop disease by targeting the removal of phytopathogens. Predatory bacteria such as myxobacteria have the potential to be used as biocontrol agents for this purpose, as they can prey upon phytopathogens, thereby reducing crop disease and promoting plant growth.Myxobacteria are able to prey upon a broad range of prey microbes, including pathogenic bacteria and fungi. While all myxobacterial isolates have a broad prey range, occasional strains exhibit unusually effective predatory activity against specific prey. Such enhanced predatory activity does not correlate with strain phylogeny, which suggests that the genes responsible for enhanced predatory activity have been inherited horizontally rather than vertically.This scenario is supported by genome sequencing, which shows that myxobacterial strains have small 'core genomes' - genes which every strain possesses. However, the majority of genes come from the 'accessory genome', which is largely unique to individual strains. Such variability between genomes can be exploited to identify the genes responsible for predation of specific prey. When predation genes have been identified, it is then possible to transplant them between strains, to generate 'super-predator' strains with increased predatory activity against particular prey, or with a broader activity against a range of prey. Super-predator strains would be advantageous for use as agricultural inoculants, as they would be better able to kill phytopathogens than environmental strains.This studentship will test the hypothesis that transplantation of prey-specific predation genes can be used to alter the prey-range of myxobacterial predators, enhancing their ability to protect crops from disease and increasing crop yields.To test this hypothesis, comparative genomics will be used to identify prey-specific predation genes in myxobacteria. Predation genes will be transplanted between strains to increase predatory activity against multiple pathogens. We will focus on novel genes and those which encode digestive enzymes/toxins rather than those which cause the production of antimicrobial compounds. We will also engineer super-predators to have reduced predatory activity against PGPRs (plant growth promoting rhizobacteria). The ability of the engineered 'super-predator to protect crops from disease and to promote plant growth will then be assessed in planta.Previously, we isolated >80 strains of Corallococcus spp., a genus of predatory myxobacteria. Around half of those strains have now been genome-sequenced, which showed that they are highly individual with large accessory genomes. Strains also exhibited diverse patterns of predatory activity against a panel of prey microbes (including pathogenic bacteria and fungi), indicating the presence/absence of prey-specific predation gene in those strains.This studentship lies at the interface between genetics, microbiology, plant biology and bioinformatics, and has been designed to gently introduce the student to an ever-expanding range of methods. The project team will provide full training in modern methods of genomic analysis, genetic engineering, microbiological techniques, gene expression measurements, plant pathology assays and bioinformatics/computational methods. Training will also be provided by the supervisors in the use of advanced computational infrastructures for genomic analyses, such as the high performance computing clusters available within IBERS, and via Supercomputing Wales. The applicability of these skills to problems across the life and medical sciences, make them 'generically' cross-disciplinary.

植物病原微生物(植物病原体)造成巨大的经济损失，威胁全球粮食安全。例如，仅在美国，仅青枯病就每年造成价值超过10亿美元的马铃薯作物损失。为了减少收获前的浪费和增加粮食安全，迫切需要通过清除植物病原体来防治作物病害。粘性细菌等捕食性细菌有可能被用作这一目的的生防剂，因为它们可以捕食植物病原体，从而减少作物病害并促进植物生长。粘性细菌能够捕食范围广泛的猎物微生物，包括病原菌和真菌。虽然所有粘性细菌分离株都有广泛的猎物范围，但偶尔的菌株对特定猎物表现出异常有效的捕食活性。这种增强的捕食活性与菌株的系统发育无关，这表明导致捕食活性增强的基因是水平遗传的，而不是垂直遗传的。基因组测序支持这一假设，这表明粘细菌菌株具有小的“核心基因组”--每个菌株都拥有的基因。然而，大多数基因来自“附属基因组”，这在很大程度上是个别菌株所独有的。基因组之间的这种变异性可以被用来识别负责捕食特定猎物的基因。一旦确定了捕食基因，就有可能在不同品系之间移植它们，产生对特定猎物具有更强捕食活性或对一系列猎物具有更广泛活动的“超级捕食者”品系。超级捕食者菌株将有利于用作农业接种剂，因为它们比环境菌株能够更好地杀灭植物病原体。本研究将检验这样一个假设，即移植特定于猎物的捕食基因可以改变粘性细菌捕食者的捕食范围，增强它们保护作物免受疾病侵袭和提高作物产量的能力。为了验证这一假设，将使用比较基因组学来确定粘杆菌中的特定于猎物的捕食基因。捕食基因将在菌株之间移植，以增加对多种病原体的捕食活性。我们将专注于新的基因和那些编码消化酶/毒素的基因，而不是那些导致产生抗菌化合物的基因。我们还将改造超级捕食者，以减少对PGPR(植物生长促进根际细菌)的捕食活性。然后将在植物中评估这种基因工程的超级捕食者保护作物免受疾病侵袭和促进植物生长的能力。此前，我们分离出了80株珊瑚球菌，一种捕食性粘性细菌的属。其中大约一半的菌株现在已经进行了基因组测序，这表明它们是高度个体的，带有大量的附属基因组。菌株对一组捕食微生物(包括病原菌和真菌)也表现出不同的捕食活动模式，表明这些菌株中存在/不存在猎物特有的捕食基因。这门课程位于遗传学、微生物学、植物生物学和生物信息学之间，旨在温和地向学生介绍不断扩大的方法范围。项目组将在基因组分析、基因工程、微生物学技术、基因表达测量、植物病理学分析和生物信息学/计算方法等现代方法方面提供全面培训。监督员还将提供关于使用先进的计算基础设施进行基因组分析的培训，例如IBERS内和通过超级计算威尔士提供的高性能计算集群。这些技能适用于生命科学和医学领域的各种问题，使它们具有“一般性”的跨学科特征。