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

这个小企业创新研究（SBIR）第一阶段项目的更广泛影响是开发第一种基于小RNA的疫苗接种方法，用于成熟的树木，葡萄树和灌木丛对抗Xylella fastidiosa（XF），这是农业中最具破坏性的细菌疾病之一。XF病害包括（1）橄榄快速衰退综合征，目前威胁整个南欧橄榄产业，杀死树龄超过1,000年的树木;（2）皮尔斯病，严重破坏南加州葡萄园;（3）柑橘杂色褪绿病，是威胁柑橘产业的几种病害之一。该项目基于该公司团队发现的一种新型感染性RNA，可用作抗病原体药物靶向XF的运载工具。一次接种可以提供终身保护，同时不会伤害树木。到目前为止，XF还没有疫苗或治愈方法。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，以对抗大多数真菌、细菌和病毒疾病。如果不进行处理，几十年后，柑橘、橄榄和许多其他为数百万人生产食物的宝贵作物可能会在温室等昆虫保护结构之外不复存在。该计划有四个关键的里程碑需要击败XF：（1）确定小干扰RNA（siRNA）能够靶向基因表达的革兰氏阴性细菌，如XF，这是从来没有实现商业化，并将这些siRNA整合到一个新的传递载体，它可以系统地感染植物没有明显的宿主范围;（2）证明在实验室宿主的韧皮部伴随细胞中产生足够的siRNA以降低XF在其专门驻留的木质部中的滴度;（3）证明本公司的新型RNA载体可以系统感染柑橘的所有商业品种，也可以系统感染橄榄树和/或葡萄藤;（4）在对XF敏感的树中扩增RNA载体，并在温室试验中证明针对XF的功效。所提出的工作将解决模型工厂N中的前两个目标。该奖项反映了NSF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.