Spaceflight microgravity and modeled-microgravity analogs (MMA) broadly alter gene expression and physiology in both pathogens and plants. Research elucidating plant and bacterial responses to normal gravity or microgravity has shown the involvement of both physiological and molecular mechanisms. Under true and simulated microgravity, plants display differential expression of pathogen-defense genes while human bacterial pathogens exhibit increased virulence, antibiotic resistance, stress tolerance, and reduced LD₅₀ in animal hosts. Human bacterial pathogens including Salmonella enterica and E. coli act as cross-kingdom foodborne pathogens by evading and suppressing the innate immunity of plants for colonization of intracellular spaces. It is unknown if evasion and colonization of plants by human pathogens occurs under microgravity and if there is increased infection capability as demonstrated using animal hosts. Understanding the relationship between microgravity, plant immunity, and human pathogens could prevent potentially deadly outbreaks of foodborne disease during spaceflight. This review will summarize (1) alterations to the virulency of human pathogens under microgravity and MMA, (2) alterations to plant physiology and gene expression under microgravity and MMA, (3) suppression and evasion of plant immunity by human pathogens under normal gravity, (4) studies of plant-microbe interactions under microgravity and MMA. A conclusion suggests future study of interactions between plants and human pathogens under microgravity is beneficial to human safety, and an investment in humanity’s long and short-term space travel goals.

航天微重力和模拟微重力类似物（MMA）广泛改变病原体和植物的基因表达和生理学。阐明植物和细菌对正常重力或微重力反应的研究表明，其中涉及生理和分子机制。在真实和模拟微重力下，植物表现出病原体防御基因的差异表达，而人类细菌病原体在动物宿主中表现出毒力增加、抗生素抗性、应激耐受性和LD _50降低。包括肠道沙门氏菌和大肠杆菌在内的人类细菌病原体通过逃避和抑制植物在细胞内空间定殖的先天免疫而成为跨界食源性病原体。目前尚不清楚人类病原体是否会在微重力下逃避和定植植物，以及动物宿主是否会增加感染能力。了解微重力、植物免疫力和人类病原体之间的关系可以防止太空飞行期间潜在致命的食源性疾病的爆发。本综述将总结(1)微重力和MMA下人类病原体毒力的改变，(2)微重力和MMA下植物生理和基因表达的改变，(3)正常重力下人类病原体对植物免疫的抑制和逃避， (4)微重力和MMA下植物-微生物相互作用的研究。结论表明，未来对微重力下植物与人类病原体之间相互作用的研究有益于人类安全，也是对人类长期和短期太空旅行目标的投资。