Liu Kun, Sun Wensong, Li Xiaoli, Shen Baoyu, Zhang Tianjing, Yu Chunlei
Liaoning Research Institute of Cash Crops, Liaoning Academy of Agricultural Sciences, Liaoyang, 111000, China.
Sci Rep. 2025 Mar 17;15(1):9172. doi: 10.1038/s41598-025-94398-z.
Chinese wild ginger (Asarum heterotropoides Fr. Schmidt var. mandshuricum (Maxim.) Kitag) is a perennial medicinal herb in China. In May 2022, 25 leaf-spot Asarum plants were collected. Employing tissue-separation and single-spore-isolation techniques, 37 fungal strains were obtained, of which seven were Didymella-like strains. Through multi-locus phylogeny and morphology analyses, these seven strains were identified as Didymella segeticola, with stain Xy0531-4 designated as the representative. In multi-locus phylogeny analysis, the concatenated fragments in the series were 1422 bp, including 395 bp of ITS, 532 bp of LSU, 358 bp of rpb2, and 137 bp of tub2. Pathogenicity tests confirmed that D. segeticola is the causal agent of Asarum leaf spot in China. Furthermore, through bioinformatic analyses, 87 putative virulence-associated proteins were encoded in the reference genome. Based on phenotypic annotations in PHI-base, these factors were categorized into three functional classes: lethal (54 proteins, associated with pathogen gene TOXA), increased virulence (hypervirulence) (19 proteins, associated with pathogen genes ChVel1 and ChLae1), and effector (plant avirulence determinant) (14 proteins, associated with pathogen genes SRE1, Cgfl, StACE1 and RsRplA). In addition, PPI network and k-means clustering analyses revealed significant phenotypic specificity in the interaction patterns of the leaf spot-associated virulence factors. These findings provide novel insights into the molecular mechanisms underlying the pathogenicity of D. segeticola, laying a foundation for future research on Asarum-leaf-spot disease management strategies.
细辛（Asarum heterotropoides Fr. Schmidt var. mandshuricum (Maxim.) Kitag）是中国的一种多年生药用草本植物。2022年5月，采集了25株患有叶斑病的细辛植株。采用组织分离和单孢分离技术，获得了37株真菌菌株，其中7株为类Didymella菌株。通过多位点系统发育和形态学分析，这7株菌株被鉴定为塞吉蒂科迪氏霉（Didymella segeticola），菌株Xy0531-4被指定为代表菌株。在多位点系统发育分析中，串联片段为1422 bp，包括ITS的395 bp、LSU的532 bp、rpb2的358 bp和tub2的137 bp。致病性测试证实，塞吉蒂科迪氏霉是中国细辛叶斑病的致病因子。此外，通过生物信息学分析，参考基因组中编码了87种假定的毒力相关蛋白。根据PHI-base中的表型注释，这些因子被分为三个功能类别：致死性（54种蛋白，与病原体基因TOXA相关）、毒力增强（超强毒力）（19种蛋白，与病原体基因ChVel1和ChLae1相关）和效应子（植物无毒决定因素）（14种蛋白，与病原体基因SRE1、Cgfl、StACE1和RsRplA相关）。此外，蛋白质-蛋白质相互作用（PPI）网络和k均值聚类分析揭示了叶斑病相关毒力因子相互作用模式中的显著表型特异性。这些发现为塞吉蒂科迪氏霉致病的分子机制提供了新的见解，为未来细辛叶斑病防治策略的研究奠定了基础。
