| 描述信息 |
Root (rhizome) rot in Polygonatum plants has received substantial attention because it threatens yield and sustainable utilization in the polygonati rhizome industry. However, the potential pathogens that cause rhizome rot as well as the direct and indirect (via root-microbe associations) strategies by which Polygonatum defends against pathogens remain largely unknown. Herein, we used integrated multiomics of plant-targeted metabolomics and transcriptomics, microbiome and culture-based methods to systematically investigate the interactions between the Polygonatum cyrtonema plantHua, root-associated microbiota and pathogens. We found that root rot inhibited P. cyrtonema rhizome growth and that fresh weight significantly decreased (P<0.001). The transcriptomic and metabonomic results showed that the expression of differentially expressed genes (DEGs) related to specialized metabolic and systemic resistance pathways, such as glycolysis/gluconeogenesis and flavonoid biosynthesis, cycloartenol synthase activity (related to saponin synthesis), mitogen-activated protein kinase (MAPK) signaling and plant hormone signal transduction, was particularly increased in diseased rhizomes. Consistently, the contents of lactose, D-fructose, sarsasapogenin, asperulosidic acid, botulin, myricadoil and other saponins, which are functional medicinal compounds in the P. cyrtonema rhizome, were also increased in diseased plants infected with rhizome rot. The microbiome sequencing and culture results showed that root rot disrupted the P. cyrtonema bacterial and fungal communities and reduced the microbial diversity in the rhizomes and rhizosphere soil. We further found that a clear enrichment of Streptomyces violascens XTBG45 (HJB-XTBG45) in the healthy rhizosphere could control the root rot caused by Fusarium oxysporum and Colletotrichum spaethianum. Taken together, our results indicate that P. cyrtonema can modulate the plant immune system and metabolic processes and enrich beneficial root microbes (rhizome and rhizosphere resistance)biota to defend against pathogens. |
