College of Food and Health, Zhejiang A&F University, Hangzhou, 311300, China.
Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, 311300, China.
Chemosphere. 2024 Sep;363:142856. doi: 10.1016/j.chemosphere.2024.142856. Epub 2024 Jul 21.
The application of organic fertilisers and biochar has become widespread in agroforestry ecosystems to enhance the yield and quality of crops and medicinal plants. However, their specific impact on both the yield and quality of Paris polyphylla (P. polyphylla), along with the underlying mechanisms, remains unclear. In this study, we investigated the distinct effects of organic fertiliser (at concentrations of 5% and 10%) and biochar application (at levels of 2% and 4%) on P. polyphylla saponin content. This content is intricately regulated by available soil nutrients, enzyme activities, and microbial community compositions and activities. Our results clearly demonstrated a significant increase in the saponin content, including total saponin, polyphyllin I (PPI), polyphyllin II (PPII), polyphyllin VI (PPVI), and polyphyllin VII (PPVII), in P. polyphylla following the application of both biochar and organic fertiliser. Moreover, in comparison to the control group, the addition of biochar and organic fertiliser led to a considerable rise in the activity of glycosyltransferase enzyme (GTS) and cycloartenol synthase (CAS) in P. polyphylla. Additionally, it increased soil available potassium (AK) and soil organic matter (SOM) concentration, along with the activity of urease, acid phosphatase, and catalase, although biochar amendment resulted in a decrease in nitrate nitrogen (NO-N) concentration. Crucially, our findings revealed a positive correlation between total saponin content and the activity of CAS in P. polyphylla, soil AK, SOM concentration, and the activities of urease, acid phosphatase, and catalase. Conversely, there was a negative correlation with NO-N content. Furthermore, the application of organic fertiliser and biochar significantly influenced microbial community structures and specific microbial taxa. Notably, total saponin content exhibited a positive relationship with the relative abundances of Dehalococcoidia, Saccharomycetes, and Agaricomycetes taxa while showing a negative correlation with the abundance of Verrucomicrobiae. In conclusion, the observed increase in saponin content can be attributed to the modulation of specific microbial taxa in soils, as well as alterations in soil nutrients and enzyme activities resulting from the application of biochar and organic fertiliser. This study identifies a potential mechanism for enhancing saponin content in the artificial cultivation of P. polyphylla.
有机肥和生物炭的应用在农林生态系统中已经广泛应用，以提高作物和药用植物的产量和质量。然而，它们对重楼（Paris polyphylla）的产量和质量的具体影响以及潜在的机制尚不清楚。在这项研究中，我们研究了有机肥（浓度为 5%和 10%）和生物炭应用（水平为 2%和 4%）对重楼皂苷含量的不同影响。土壤养分、酶活性以及微生物群落组成和活性对皂苷含量的调节非常复杂。我们的结果清楚地表明，生物炭和有机肥的应用显著增加了重楼的皂苷含量，包括总皂苷、重楼皂苷 I（PPI）、重楼皂苷 II（PPII）、重楼皂苷 VI（PPVI）和重楼皂苷 VII（PPVII）。与对照组相比，生物炭和有机肥的添加导致重楼糖苷转移酶（GTS）和环阿屯醇合酶（CAS）的活性显著升高。此外，它增加了土壤有效钾（AK）和土壤有机质（SOM）浓度，以及脲酶、酸性磷酸酶和过氧化氢酶的活性，尽管生物炭的添加导致硝态氮（NO-N）浓度降低。重要的是，我们的研究结果发现重楼总皂苷含量与 CAS 活性、土壤 AK、SOM 浓度以及脲酶、酸性磷酸酶和过氧化氢酶的活性呈正相关，而与 NO-N 含量呈负相关。此外，有机肥和生物炭的应用显著影响了微生物群落结构和特定的微生物类群。值得注意的是，总皂苷含量与 Dehalococcoidia、Saccharomycetes 和 Agaricomycetes 类群的相对丰度呈正相关，而与 Verrucomicrobiae 的丰度呈负相关。总之，皂苷含量的增加可归因于土壤中特定微生物类群的调节，以及生物炭和有机肥应用导致土壤养分和酶活性的改变。本研究确定了一种提高人工栽培重楼中皂苷含量的潜在机制。
