SBIR Phase I: Using a novel RNA therapy to immunize trees and vines against deadly bacteria

这项小企业创新研究（SBIR）第一阶段项目的更广泛影响是开发第一个基于rna的小型疫苗接种方法，用于成熟的树木、藤蔓和灌木，以对抗农业中最具破坏性的细菌性疾病之一——苛刻木杆菌（XF）。XF疾病包括：(1)橄榄树快速衰退综合征，目前威胁着整个南欧的橄榄产业，并杀死了超过1000年的树；(2)皮尔斯病，严重破坏了南加州的葡萄园；(3)柑橘黄萎病，柑橘黄萎病是危害柑橘产业的几种病害之一。该项目基于公司团队发现的一种新型感染性RNA，该RNA可作为抗致病性药物靶向XF的递送载体。单次接种可以提供潜在的终身保护，而不会伤害树木。到今天为止，还没有针对XF的疫苗或治疗方法。如果成功，这将代表一个新的平台，有可能为大多数树木接种疫苗，对抗大多数真菌、细菌和病毒疾病。如果不进行治疗，几十年后，柑橘、橄榄和许多其他为数百万人提供食物的有价值的作物可能会在温室等防虫结构之外不复存在。该项目有四个关键的里程碑需要击败XF:(1)鉴定小干扰rna （sirna）能够靶向基因表达的革兰氏阴性细菌，如XF，这从未在商业上完成，并将这些sirna整合到一个新的传递载体，可以系统地感染没有明显宿主范围的植物；(2)证明在实验室宿主的韧皮部伴随细胞中产生了足够的sirna来降低XF在木质部的滴度，而木质部是XF唯一存在的地方；(3)表明，该公司的新型RNA载体，可以系统感染柑橘的所有商品品种，也可以系统感染橄榄树和/或葡萄藤；(4)在XF易感树木中扩增RNA载体，并在温室试验中验证了抗XF的有效性。拟议的工作将解决模式植物N. bethamiana的前两个目标和橄榄和葡萄藤的第三个目标。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The broader impact of this Small Business Innovation Research (SBIR) Phase I project is to develop the first small RNA-based vaccination approach for mature trees, vines, and bushes against Xylella fastidiosa (XF), one of agriculture’s most devastating bacterial diseases. XF diseases include (1) Olive Quick Decline Syndrome, which is currently threatening the entire Southern Europe olive industry and killing trees that are over 1,000 years old; (2) Pierce’s Disease, which has severely damaged Southern California vineyards; and (3) Citrus Variegated Chlorosis, which is one of several diseases threatening the citrus industry. This project is based on a novel infectious RNA discovered by the Company’s team that can be used as a delivery vehicle for anti-pathogenic agents to target XF. A single inoculation can potentially provide lifetime protection while not harming the tree. As of today, there is no vaccination or cure for XF. If successful, this would represent a new platform potentially capable of vaccinating most trees against most fungal, bacterial, and viral diseases. In the absence of treatment, in a few decades, citrus, olives, and many other valuable crops that produce food for millions of people may cease to exist outside of insect-protective structures like greenhouses. The proposed project has four key milestones required to defeat XF: (1) identify small interfering RNAs (siRNAs) capable of targeting gene expression in a Gram-negative bacterium like XF, which has never been accomplished commercially, and integrate these siRNAs into a novel delivery vector, which can systemically infect plants with no apparent host range; (2) demonstrate that sufficient siRNAs are generated in phloem companion cells in a laboratory host to reduce titers of XF in the xylem where it exclusively resides; (3) show that the Company’s novel RNA vector, which can systemically infect all commercial varieties of citrus, can also systemically infect olive trees and/or grapevines; (4) amplify the RNA vector in trees susceptible to XF and demonstrate efficacy against XF in greenhouse trials. The proposed work will address the first two objectives in the model plant N. bethamiana and the third objective in olive and grapevines.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.