Advancements and prospects in host specificity of Epichloë endophytes

Abstract:

Gramineous plants, known for their extensive distribution and substantial economic importance, have garnered significant interests. Epichloë endophytes maintain mutualistic symbiosis with cool-season gramineous plants, demonstrating strict host specificity. This review aims to facilitate the foundational research on Epichloë by summarizing the research progress in their host specificity. Initially, this review delineates the fundamental attributes of gramineous plant endophytes, emphasizing the host specificity of Epichloë through seed transmission and genetic evolution. Endophytic fungi, mycorrhizal fungi, and pathogenic fungi of plants are compared. The pivotal role of noxA in modulating “symbiosis versus pathogenicity” in host plants is expounded, and a potential link in host specificity across these three categories of plant-associated fungi is suggested. It is posited that the host specificity mechanisms of Epichloë might offer insights into the host specificity of both plant pathogenic fungi and mycorrhizal fungi. Finally, this review summarizes the recent advancements in omics-era, expecting that these emerging technologies will advance the discovery of novel genes and deepen the understanding of fungal host specificity. It emphasizes the importance of developing effective artificial inoculation techniques for Epichloë as a means to investigate host specificity. These research efforts are expected to help create new endophyte-host combinations in the future.