The conversion of natural forest understories to monoculture plantations of high-value medicinal herbs is widespread in China, yet its long-term impacts on the soil microbiome remain poorly quantified, raising concerns about the long-term sustainability of such agroforestry systems. The soils were sampled from forest understory systems in the Qinling-Bashan Mountains (Shaanxi Province, China), classified as Luvisols according to the World Reference Base for Soil Resources (WRB). Sites included undisturbed native forest (Y), Asarum sieboldii Miq. (ASM) monocultures (3-year: X; 5-year with robust/poor vigor: Q/R), and post-harvest abandoned land (F). To understand how soil microbial communities form and respond to different land uses in terms of composition and function, we combined soil physicochemical analysis, high-throughput 16S rRNA gene sequencing, null model analysis, co-occurrence network construction, and functional prediction. Across the sampling gradient from the original forest to the abandoned land, available soil phosphorus (AP) decreased by over 50%, pH increased from 5.6 to above 7.4, and ammonium nitrogen (\({\text{NH}}_{4}^{ + }\)–N) increased significantly by 80%. This was accompanied by a progressive decline in NST from 0.42 (Y) to 0.16 (F), confirming strengthening deterministic selection. ASM monoculture significantly altered the structure of bacterial communities. As cultivation duration increased, abundant bacterial taxa became more dominant and upregulated genes associated with nutrient acquisition and stress response (e.g., membrane transport). In contrast, rare taxa experienced a substantial loss of diversity and exhibited no consistent directional trends in functional potential, reflecting high context-dependency. Notably, after land abandonment, these trends began to reverse, with abundant taxa decreasing and rare taxa showing signs of recovery. Compared to plots with poor plant growth (R), soil from plots with robust growth (Q) maintained 5.26% higher bacterial richness and had 26% more rare microbial taxa. Network analysis revealed a filtering-driven reorganization of microbial co-occurrence networks, including shifts in module structure and the dominant taxa within them. ASM monoculture induced shifts in soil nutrients and pH, establishing strong environmental filters. These changes increasingly constrained microbial community assembly toward deterministic processes, resulting in reduced diversity, particularly among rare taxa, and ultimately compromising the stability of the overall microbial community. To sustain long-term soil health and productivity, forest-based agroecosystems must conserve soil microbial diversity by mitigating phosphorus depletion and stabilizing soil pH, both of which are essential for microbial resilience.

This study investigated the interactive effects of different light conditions and weed control methods on the medicinal compound composition and rhizosphere bacterial community structure of Epimedium sagittatum. A completely randomized block design was employed, incorporating four treatments: full light with manual weeding (LN), shade with manual weeding (SN), full light with weed-control fabric mulch (LG), and shade with mulch (SG). Active compound levels in two-year-old plants were quantified using HPLC, and rhizobacterial diversity was assessed via high-throughput sequencing. The results indicated that the SG treatment significantly enhanced the photosynthetic efficiency and yielded the highest levels of epimedin C and total active compounds. In contrast, the SN treatment fostered a beneficial rhizosphere environment—characterized by increased pH, ammonium nitrogen (NH₄⁺-N), bacterial diversity, and the abundance of Flavobacterium—which supported the highest production of epimedin B and icariin. Redundancy analysis confirmed that these microbial shifts were primarily driven by soil pH, nitrate nitrogen (NO₃⁻-N), and shading. Furthermore, while stochastic processes governed bacterial community assembly, deterministic selection intensified across the treatments from LN to SG. Collectively, our findings demonstrate that light and mulching can be strategically tailored to manipulate the plant–soil-microbe system, thereby enabling precise modulation of the medicinal quality of E. sagittatum.

Background: Vicia faba L. is a significant grain legume that is rich in protein and nutrients. It is widely cultivated for human consumption and animal feed in temperate regions. As a signaling molecule, fructose is involved in many metabolic and developmental processes. The objective of this study was to demonstrate whether fructose may increase reactive oxygen species (ROS) production in guard cells inducing stomatal closure and examine whether the exogenous application of fructose may regulate photosynthesis and chlorophyll fluorescence characteristics. Methods: After approximately 4 weeks of sowing the treated broad bean seeds, the fully inflated leaves were used for experimental data collection including stomatal movement, gas exchange, chlorophyll fluorescence and ROS production in guard cells. Result: Fructose reduced stomatal conductance (Gs), transpiration rate (Tr) and stomatal aperture of intact leaves, indicating that fructose can trigger stomatal closure in a dose- and time-dependent manner in the epidermal peels of the broad bean plant (Vicia faba L.). Meanwhile, fructose increased the photochemical efficiency, photosynthetic rate (Pn) and water use efficiency (WUE). Fructose-induced stomatal closure was associated with nitric oxide (NO), calcium ion (Ca2+), aquaporin and ROS.