Nanotechnology has been developed for plant disease management, and many kinds of organic nanoparticles have been developed to induce the immunity of plants, such as plant vaccines. Natural products from Chaetomium lucknowense, Chaetomium brasiliense, Chaetomium cochliodes, Chaetomium cupreum, Chaetomium elatum, Chaetomium globosum, Chaetomium siamense, Emericella nidulans, Trichoderma harzianum, and Trichoderma hamatum are reported to have antimicrobial activities against plant pathogens. In particular, Ch. siamense is a newly discovered and endophytic Chaetomium spp. that produces active metabolites. These active metabolites from Chaetomium spp., E. nidulans, T. harzianum, and T. hamatum are constructed as nanofibers for inducing plant disease immunity through phytoalexin production as nanoplant vaccines. The nanofibers are used as elicitors for the induction of immunity in plants that induce phytoalexin biosynthesis, for example, scopoletin and anthocyanidin against Phytophthora or Pythium rot and scoparone against Phytophthora or Pythium rot, capsidiol in chili against anthracnose, alpha-tomatine in tomato against Fusarium wilt, and sakuranetin and oryzalexin in rice plants against blast. The natural product nanoelicitors derived from Chaetomium spp., Emericella spp., and Trichoderma spp. help reduce disease incidence in plants.