Develop innovative stable RNA-based anti-fungal reagents to control plant fungal diseases

真菌可引起植物和动物的毁灭性疾病，对全球粮食安全和人类健康构成巨大威胁。在人类中，真菌疾病估计每年造成150万人死亡。在植物中，真菌病原体会对大多数收获前和收获后的作物造成严重疾病，每年在世界范围内造成数十亿美元的损失。尽管存在这些威胁，但目前对抗真菌疾病的策略仅限于化学控制。在农业中，杀菌剂会在环境中留下有害残留物。此外，真菌已经发展出耐药菌株，可以在几乎所有主要种类的抗真菌药物和杀菌剂中存活。为了保护全球粮食安全、人类健康和环境，开发防治真菌疾病的新技术至关重要。小rna是短调控分子，可以抑制其靶基因的表达。这被称为RNA干扰。最近，研究小组发现，多种真菌病原体可以有效地从环境中吸收rna作为营养来源。当真菌吸收干扰关键真菌蛋白表达的rna时，它们的生长和毒力受到严重抑制。这一发现允许他们设计特定的RNA分子，可以针对真菌毒力相关基因来保护作物免受真菌感染。这些基于rna的抗真菌药物可以喷洒到植物材料上，通过一种称为“喷雾诱导基因沉默”（SIGS）的过程，为植物提供真菌疾病保护。与传统的杀菌剂不同，这些基于rna的抗真菌剂可以安全摄入，并且不会在土壤中留下有毒残留物。本项目旨在建立和实现基于rna的植物病原体免疫策略。要做到这一点，该项目将首先解决一个限制强大功能的重大障碍：RNA在环境中迅速降解，特别是在土壤中，许多植物真菌病原体的起源。目前的项目旨在解决这一问题，并进一步开发基于rna的抗真菌策略。一个目标是设计能够保护植物免受四种侵袭性病原体侵害的SIGS rna。同时，为了提高SIGS RNA的稳定性，PI将开发几种由有机和无机材料制成的RNA运载工具。虽然初步数据表明这些RNA载体可以增强RNA在植物材料上的稳定性，但它们不足以保护土壤中的RNA。为了开发有效的基于rna的抗真菌药物来控制土壤传播的真菌病原体，PI将设计有益的土壤微生物，特别是一种细菌和一种真菌，不断地产生和分泌抗真菌rna到土壤中。总体而言，该项目将开发下一代基于rna的抗真菌药物来对抗植物真菌病原体，这将直接为确保全球粮食安全做出贡献。此外，一旦在植物中发展起来，这些基于rna的抗真菌策略可以转化为人类和动物系统。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。

Fungi can cause devastating diseases in plants and animals, posing an enormous threat to global food security and human health. In humans, fungal diseases are estimated to kill 1.5 million people every year. In plants, fungal pathogens cause serious diseases on most pre- and post-harvesting crops and causes billions of dollars loss worldwide every year. Despite these threats, current strategies for fighting fungal disease are limited to chemical control. In agriculture, fungicides can leave harmful residues in the environment. Further, fungi have developed resistant strains that can survive nearly all major classes of antifungal drugs and fungicides. In order to protect global food security, human health, and the environment it is critical to develop new technologies for combating fungal disease. Small RNAs are short regulatory molecules that can inhibit the expression of their target genes. This is called RNA interference. Recently, the research team discovered that multiple fungal pathogens can efficiently take up RNAs as a nutrient source from the environment. When fungi absorb RNAs that interfere with the expression of critical fungal proteins, their growth and virulence is severely inhibited. This finding allows them to design specific RNA molecules that can target fungal virulence-related genes to protect crops from fungal infection. These RNA-based antifungals can be sprayed onto plant material where they confer fungal disease protection to the plant, through a process called Spray-Induced Gene Silencing (SIGS). Unlike traditional fungicides, these RNA-based antifungals are safe to ingest and do not leave toxic residues in the soil. This project aims to establish and depoly RNA-based strategies for plant-pathogen immunity. To do this, the project will first address a significant hurdle limiting robust function: RNA rapidly degrades in the environment, especially in the soil, where many plant fungal pathogens originate. The current project aims to tackle this problem, and to further develop RNA-based antifungal strategies. One goal is to design SIGS RNAs capable of protecting plants from four aggressive pathogens. Concurrently, in order to enhance the stability of SIGS RNAs, the PI will develop several classes of RNA delivery vehicles, made of both organic and inorganic materials. While preliminary data shows that these RNA delivery vehicles can enhance the stability of RNAs on plant material, they are not sufficient in protecting RNA in the soil. In order to develop effective RNA-based antifungals to control soil-borne fungal pathogens, the PI will engineer beneficial soil microbes, specifically one bacterium and one fungus, to continuously produce and secrete antifungal RNAs into the soil. Overall, this project will develop the next generation of RNA-based antifungals to combat plant fungal pathogens, which will directly contribute to securing global food security. Further, once developed in plants, these RNA-based antifungal strategies can be translated into human and animal systems.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.