Analysis of the variation characteristics of Scutellaria baicalensis rhizosphere soil microorganisms at different growth stages and their relationship with the accumulation of active components

In this study, Scutellaria baicalensis Gerog plants at different growth stages and their rhizosphere soil were used as experimental materials. The microbial diversity, physicochemical properties, and enzyme activities of the rhizosphere soil were systematically determined, while the active component contents of Scutellaria baicalensis shoots were analyzed. This research aims to provide a scientific basis for revealing the soil environment regulation mechanism underlying the accumulation of active components in Scutellaria baicalensis root. It revealed the association mechanisms between rhizosphere soil micro-ecological characteristics at different growth stages and active component accumulation of Scutellaria baicalensis root. The results showed that, compared with the flowering stage, the contents of total phosphorus (TP), alkali-hydrolyzable nitrogen (AN), soil organic carbon (SOC), microbial biomass carbon (MBC), and microbial biomass nitrogen (MBN), as well as the carbon/nitrogen (C/N) ratio, in Scutellaria baicalensis rhizosphere soil gradually increased during the fruiting and wilting stages. In contrast, the soil pH showed an opposite trend. Among the other soil nutrients, the contents of TP, available phosphorus (AP), and available potassium (AK) were the highest at the fruiting stage, followed by the wilting stage, the lowest at the wilting stage. Additionally, the TN content was the lowest at the flowering stage, and it was higher at the fruiting and wilting stages. Compared with the flowering stage, the activities of urease, sucrase, and alkaline phosphatase in Scutellaria baicalensis rhizosphere soil significantly increased at the fruiting and wilting stages. There are significant differences of bacterial community in Scutellaria baicalensis rhizosphere soil at different growth stages (flowering stage, fruiting stage, and withering stage). The relative abundance of bacteria at the genus level in Scutellaria baicalensis rhizosphere soil changes with the growth stages. The dominant genera in each stage is as follows: at the flowering stage, the dominant taxa are Bacillus , Geodermatophilus , and Bryobacte ; at the fruiting stage, the dominant taxa are Streptomyces , Sphingomonas , Blastococcuss , Haliangium , and Nocardioides ; At thewithering stage, the dominant taxa are Gemmatimonas , Opitutus , and Lysobacter . The relative abundance of fungi in Scutellaria baicalensis rhizosphere soil at the genus level changes with the growth stages. The dominant genera in each stage are as follows: at the flowering stage, the genera with the highest relative abundance are Arthrographis , Penicillium and Preussia ; at the fruiting stage, the genera with the highest relative abundance are Pseudogymnoascus , Aspergillus and Pseudallescheria ; at the withering stage, the genera with the highest relative abundance are Mortierella , Alternaria , Mycochlamys and Fusarium . Redundancy analysis indicated that AN and MBN were key environmental factors driving the differences of bacterial and fungal communities at the genus level in Scutellaria baicalensis rhizosphere soil at different growth stages. Pearson correlation analysis further showed that the main active components of Scutellaria baicalensis root, including baicalin, wogonoside, baicalein, and wogonin, were significantly positively correlated with the relative abundance of 10 bacterial genera such as Gemmatimonas , Opitutus , and Lysobacter , as well as with the relative abundance of 12 fungal genera such as Mortierella , Alternaria , and Mycochlamys . These results reveal that the rhizosphere microbial community plays an important role in the accumulation of root active components at different growth stages of Scutellaria baicalensis , providing a theoretical basis for the development of precision fertilization strategies and scientific management in Scutellaria baicalensis cultivation.