Data_Sheet_1_Root exudates influence rhizosphere fungi and thereby synergistically regulate Panax ginseng yield and quality.pdf

Root exudates contain a complex array of primary and specialized metabolites that play important roles in plant growth due to their stimulatory and inhibitory activities that can select for specific microbes. In this study, we investigated the effects of different root exudate concentrations on the growth of ginseng (Panax ginseng C. A. Mey), ginsenoside levels, and soil fungal community composition and diversity. The results showed that low root exudate concentrations in the soil promoted ginseng rhizome biomass and ginsenoside levels (Rg1, Re, Rf, Rg2, Rb1, Ro, Rc, Rb2, Rb3, and Rd) in rhizomes. However, the rhizome biomass and ginsenoside levels gradually decreased with further increases in the root exudate concentration. ITS sequencing showed that low root exudate concentrations in the soil hardly altered the rhizosphere fungal community structure. High root exudate concentrations altered the structure, involving microecological imbalance, with reduced abundances of potentially beneficial fungi (such as Mortierella) and increased abundances of potentially pathogenic fungi (such as Fusarium). Correlation analysis showed that rhizome biomass and ginsenoside levels were significantly positively correlated with the abundances of potentially beneficial fungi, while the opposite was true for potentially pathogenic fungi. Overall, low root exudate concentrations promote the growth and development of ginseng; high root exudate concentrations lead to an imbalance in the rhizosphere fungal community of ginseng and reduce the plant’s adaptability. This may be an important factor in the reduced ginseng yield and quality and soil sickness when ginseng is grown continuously.

根部分泌物中含有复杂多样的初级和特殊代谢物，这些代谢物在植物生长中发挥着重要作用，其刺激和抑制作用能够选择性地促进特定微生物的生长。在本研究中，我们探讨了不同根部分泌物浓度对人参（Panax ginseng C. A. Mey）生长、人参皂苷含量以及土壤真菌群落组成和多样性的影响。研究结果表明，土壤中低浓度的根部分泌物促进了人参根茎的生物量和人参皂苷含量（包括Rg1、Re、Rf、Rg2、Rb1、Ro、Rc、Rb2、Rb3和Rd），然而，随着根部分泌物浓度的进一步增加，根茎的生物量和人参皂苷含量逐渐降低。ITS测序结果显示，土壤中低浓度的根部分泌物对根际真菌群落结构的影响微乎其微。而高浓度的根部分泌物则改变了群落结构，表现为微生态失衡，有益真菌（如Mortierella）的丰度降低，而致病真菌（如Fusarium）的丰度增加。相关性分析表明，根茎的生物量和人参皂苷含量与有益真菌的丰度呈显著正相关，而与致病真菌的丰度呈负相关。总体而言，低浓度的根部分泌物有利于人参的生长与发展；而高浓度的根部分泌物则导致人参根际真菌群落的失衡，降低植物的抗逆性。这可能是人参连续种植导致产量和质量下降以及土壤病害的重要影响因素。