禾本科植物Epichloë属内生真菌的宿主特异性研究及展望

Advancements and prospects in host specificity of Epichloë endophytes

摘要:

禾本科植物在自然界分布广泛，因经济价值巨大而备受关注。Epichloë属内生真菌与冷季型禾本科植物互利共生，具有严格的宿主特异性。为促进关于Epichloë属内生真菌的基础研究，本文围绕Epichloë属内生真菌严格的宿主特异性进行了总结和展望。首先，本文阐述了禾本科植物内生真菌的基本特点，通过其种传特性和遗传进化特征，引出了Epichloë属内生真菌的宿主特异性及其重要性。然后，就植物内生真菌、植物菌根真菌及植物病原真菌分别进行了介绍和比较，并介绍了宿主植物的noxA基因在共生/加害的选择中的重要性，引出了宿主特异性在这三类植物相关真菌之间可能的关联，提出了研究Epichloë属内生真菌的宿主特异性，与理解植物病原真菌和植物菌根菌的宿主特异性之间可能存在一定的共通/类似机理的观点。最后，总结了近年来组学研究的相关进展，期待这些新技术新手段在真菌宿主特异性研究、相关新基因探索方面发挥推动作用。同时也指出Epichloë属内生真菌的高效人工接种技术的开发对于宿主特异性研究的重要性，期待这些研究为今后的“内生真菌-宿主新组合”的创制发挥重要作用。

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.