Goodwin Paul H, Hsiang Tom
School of Environmental Sciences, University of Guelph, 50 Stone Road East, Guelph, ON N1G 2W1, Canada.
Biology (Basel). 2024 Aug 29;13(9):671. doi: 10.3390/biology13090671.
A prior report showed that soil previously planted with American ginseng () contained compound(s) which could reduce ginseng resistance to root infection by , and this was not found in extracts from ginseng roots or soils not previously planted with ginseng. However, the origin of this ginseng-related factor in ginseng soils is unknown. An isolate of obtained from soil where had been harvested grew more in culture media when ginseng root extract was included, indicating the use of compounds in the extract as nutrients. Treatment with cell-free extracts from media containing ginseng root extracts where had been cultured resulted in root lesions caused by being significantly larger than roots treated with fresh media containing root extract or with cell-free media inoculated with the same bacterial isolate without root extract. Levels of ginsenosides in the media decreased over time with incubation. Genome sequencing revealed that the bacterium had genes homologous to those reported for ginsenoside metabolism, which can release sugars for microbial growth. Thus, a ginseng soil bacterium, , can create compound(s) suppressive to root rot resistance, similar to that found in soils previously planted with ginseng, indicating that the activity suppressing root rot resistance in soil previously planted with ginseng may be of microbial origin, utilizing compounds from ginseng roots.
先前的一份报告显示，之前种植过西洋参的土壤中含有能够降低西洋参对根腐病菌抗性的化合物，而在西洋参根提取物或之前未种植过西洋参的土壤提取物中未发现此类化合物。然而，西洋参土壤中这种与西洋参相关因子的来源尚不清楚。从收获过西洋参的土壤中分离得到的根腐病菌，在含有西洋参根提取物的培养基中生长得更好，这表明提取物中的化合物被用作营养物质。用含有在培养过根腐病菌的西洋参根提取物的培养基的无细胞提取物处理，导致由根腐病菌引起的根部病斑明显大于用含有根提取物的新鲜培养基或接种相同细菌分离株但不含根提取物的无细胞培养基处理的根部。随着培养时间的延长，培养基中人参皂苷的含量逐渐降低。基因组测序显示，该细菌具有与报道的人参皂苷代谢相关基因同源的基因，这些基因可以释放糖类以供微生物生长。因此，可以产生对根腐病抗性有抑制作用的化合物，类似于在之前种植过西洋参的土壤中发现的情况，这表明之前种植过西洋参的土壤中抑制根腐病抗性的活性可能起源于微生物，利用了西洋参根中的化合物。
