Department of Plant Pathology, College of Agriculture, Guizhou University, Guiyang 550025, China; Engineering and Research Center for Southwest Biopharmaceutical Resource of National Education Ministry of China, Guizhou University, Guiyang 550025, China.
Engineering and Research Center for Southwest Biopharmaceutical Resource of National Education Ministry of China, Guizhou University, Guiyang 550025, China; Key Laboratory of Green Pesticide and Agricultural Bioengineering, Guizhou University, Guiyang 550025, China.
Genomics. 2024 Sep;116(5):110925. doi: 10.1016/j.ygeno.2024.110925. Epub 2024 Aug 22.
Fungal-plant interactions have persisted for 460 million years, and almost all terrestrial plants on Earth have endophytic fungi. However, the mechanism of symbiosis between endophytic fungi and host plants has been inconclusive. In this dissertation, we used a strain of endophytic Fusarium lateritium (Fl617), which was found in the previous stage to promote disease resistance in tomato, and selected the pathogenic Fusarium oxysporum Fo4287 and endophytic Fusarium oxysporum Fo47, which are in the same host and the closest relatives of Fl617, to carry out a comparative genomics analysis of the three systems and to provide a new perspective for the elucidation of the special lifestyle of the fungal endophytes. We found that endophytic F. lateritium has a smaller genome, fewer clusters and genes associated with pathogenicity, and fewer plant cell wall degrading enzymes (PCWDEs). There were also relatively fewer secondary metabolisms and typical Fusarium spp. toxins, and a lack of the key Fusarium spp. pathogenicity factor, secreted in xylem (SIX), but the endophytic fungi may be more sophisticated in their regulation of the colonization process. It is hypothesized that the endophytic fungi may have maintained their symbiosis with plants due to the relatively homogeneous microenvironment in plants for a long period of time, considering only plant interactions and discarding the relevant pathogenicity factors, and that their endophytic evolutionary tendency may tend to be genome streamlining and to enhance the fineness of the regulation of plant interactions, thus maintaining their symbiotic status with plants.
真菌与植物的相互作用已经持续了 4.6 亿年，地球上几乎所有的陆生植物都有内生真菌。然而，内生真菌与宿主植物共生的机制尚未得到明确的结论。在本论文中，我们使用了一株内生镰孢菌（Fl617），该菌株在之前的研究中被发现能够促进番茄的抗病性，选择了致病镰孢菌 Fo4287 和内生镰孢菌 Fo47，它们在同一宿主中，并且与 Fl617 亲缘关系最近，对这三个系统进行了比较基因组学分析，为阐明真菌内生菌的特殊生活方式提供了新的视角。我们发现，内生镰孢菌 Fl617 的基因组较小，与致病性相关的基因簇和基因较少，植物细胞壁降解酶（PCWDE）较少。次生代谢物和典型的镰孢毒素也相对较少，并且缺乏关键的镰孢属致病因子，即木质部分泌（SIX），但内生真菌可能在调控定植过程方面更加复杂。我们假设，内生真菌可能由于植物内部相对同质的微环境，长期以来一直与植物保持共生关系，只考虑植物相互作用，而摒弃相关的致病性因素，其内生进化趋势可能倾向于基因组简化，并增强对植物相互作用的调控精细度，从而维持其与植物的共生状态。
