Résumé
ObjectiveTo explore the forest type and soil environment suitable for Panax ginseng. MethodThe yield， quality， soil chemical properties， soil enzyme activity， and soil microbial metabolism of 9-year-old P. ginseng under different forests were investigated. ResultThe quality of P. ginseng was significantly different among forest types. To be specific， P. ginseng under the Quercus mongolica forest had the highest quality， with the total saponin content of 2.27% which was 51.89% higher than that in P. ginseng under Larix gmelinii forest. The yield of P. ginseng under Q. mongolica forest and L. gmelinii forest （30 g·m-2） was the highest， 62.5% higher than that under Betula platyphylla forest. The soil content of organic matter， Cu， and Zn， and activity of sucrase and urease under Q. mongolica forest were lower than those under other forest types. The utilization rate of D-galacturonic acid by soil microorganisms under Q. mongolica forest was higher than that under other forest types， but the utilization rate of L-phenylalanine was lower than that under other forest types. The utilization rate of 2-hydroxybenzoic acid by soil microorganisms of B. platyphylla forest was significantly lower than that under other forest types. There was a negative correlation between soil Zn and ginsenoside Rb1 and Rc， and between soil K and ginsenoside Rb2 and Rb3. Mn and Cu were positively correlated with most saponins. The results of redundancy analysis showed that the soil microorganisms using carbon sources of amino acids， esters， acids， and sugars were the main factors causing the differences in P. ginseng among different forest types. ConclusionThe yield and quality of P. ginseng under Q. mongolica forest were the best， followed by the forest with different tree species， and coming in last was the B. platyphylla forest. This study is expected to provide theoretical support for the improvement of P. ginseng yield and quality and the improvement of ecological planting technology.
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ObjectiveTo investigate the effects of exogenous Fusarium oxysporum and Trichoderma viride on the diversity of soil fungal community and carbon metabolic function of cultivated Panax ginseng. MethodIllumina HiSeq 2500 high-throughput sequencing combined with Biolog-ECO was used to analyze the species diversity and functional diversity of soil fungal communities in P. ginseng soil under different exogenous treatments. ResultThe results of high-throughput sequencing showed that the number and species of microorganisms in the soil were significantly changed after exogenous microorganisms were added. The soil fungi with relative abundance greater than 1% included Mortierella sp.，Fusarium sp.，Humicola sp.，and Simplicillium sp. Mortierella sp. in each treatment group significantly increased. Humicola sp. and Simplicillium sp. could be induced to increase by exogenous addition of F. oxysporum，while T. viride at a high concentration could significantly inhibit the growth of F. oxysporum. As revealed by Biolog and principal component analysis （PCA），the average well color development （AWCD） in the high-dose T. viride group （MG） was significantly higher than that in the control group （QS）and the low-dose F. oxysporum group（LD）. The utilization abilities for amino acids，carboxylic acids，polymers， and amines were enhanced in the MG group，but the microbial metabolic activity was reduced in the high-dose F. oxysporum group （LG）. There was no significant increase in the utilization of phenolic acids by soil microorganisms in both groups. ConclusionExogenous addition of F. oxysporum can lead to the growth and reproduction of other pathogenic fungi. Exogenous addition of T. viride can enhance the soil fungal community structure and metabolic diversity，inhibit the proliferation of F. oxysporum，and improve the soil microbial environment of cultivated P. ginseng.
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Background: Studies have shown that intestinal microbiota is closely related to the occurrence and development of depression, however, the regulatory mechanism of the classic antidepressant fluoxetine on intestinal microbiota is still unclear. Aims: To investigate the mechanism of fluoxetine in regulating intestinal microbiota structure and metabolic diversity in rats with depression. Methods: Thirty SD rats were randomly divided into blank group, model group and fluoxetine group. Depression rat model was established by chronic unpredictable mild stress (CUMS) combined with solitary care. Fluoxetine hydrochloride dispersible tablets 3.17 mg•kg
Résumé
Chronic unpredicted mild stress(CUMS) combined with isolated feeding was used to induce depressed rat model. The anti-depressant effects of Zhizichi Decoction(ZZCD) and its solid fermented product(ZZC) were analyzed by behavioral test and comparison of pathological tissues of hippocampus and liver, metabolic characteristics of intestinal flora, and relative abundance of species. The results showed that ZZC could increase sucrose preference, shorten the immobility time in the forced swim test and tail suspension test(P<0.05), and repair damaged hippocampus and liver tissues, and the effect was superior to that of ZZCD. The results of Biolog ECO plates showed that the average well color development(AWCD) of intestinal flora in the model group significantly decreased and the metabolic levels of sugar and amino acids were reduced, while the AWCD of the treatment groups increased. The metabolic levels of the two carbon sources were improved in the ZZC group, while only sugar metabolic level was elevated in the ZZCD group. Metagenomic analysis of intestinal flora showed that the ratio of Firmicutes/Bacteroidetes was 3.87 in the control group, 21.77 in the model group, 5.91 in the ZZC group, and 18.48 in the ZZCD group. Lactobacillus increased by 3.28 times, and Prevotella and Bacteroidetes decreased by 75.59% and 76.39%, respectively in the model group as compared with that in the control group. Lactobacillus decreased by 31.13%, and Prevotella and Bacteroidetes increased by more than three times in the ZZC group as compared with that in the model group, while the corresponding changes in the ZZCD group were not significant. ZZC could improve depression-like beha-viors by regulating the structure of intestinal flora and metabolic functions and repairing damaged hippocampus and liver tissues in depressed rats, showing an anti-depressant effect superior to that of ZZCD. This study is expected to provide a basis for the development of new anti-depressant food products.