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Abstract Semen Ziziphi Spinosae (SZS) is a traditional Chinese herbal medicine widely used to treat insomnia and anxiety in clinical practice. Currently, the demand for SZS is increasing every year, but the production of wild SZS is unstable due to environmental factors. Grafting sour jujube scions onto sour jujube or jujube tree stocks can achieve a high production rate within a short period of time. However, the effects of grafting on the quality of SZS have not been reported. This study investigated the differences between wild-type and grafted SZS from three aspects: phenotype, chemical composition, and molecular mechanism. The findings revealed that the grafted specimens were generally larger in morphology and lighter in color than the wild-type samples. The dimensions of both the grafted specimens were generally larger than those of the wild specimens. The HPLC-ELSD results revealed that the three main chemical components in the grafted SZS, namely, spinosin, jujuboside A, and jujuboside B, had higher contents than their wild-type counterparts. Comprehensive transcriptome sequencing analysis and KEGG annotation revealed that DEG enrichment between grafted and wild-type SZS occurred mainly during stress resistance and rootstock scion healing. There were 23 DEGs that may encode enzymes involved in the biosynthetic pathway of flavonoids and 21 genes encoding terpenoid saponins. Further investigation revealed that the expression of the genes C4H, CHS, CHI, and F3’5’H in the flavonoid biosynthesis pat.hway and HMGR, MVK, MVD, and FPPS in the saponin biosynthesis pathway accounted for the difference in quality between grafted and wild SZS. Furthermore, WGCNA identified 15 core genes related to medicinal ingredients between grafted and wild SZS. These results provide support for further research on the differences in the quality of medicinal ingredients between grafted and wild SZS.

This work aimed to identify the allelochemicals released by Glehnia littoralis Fr. Schmidt ex Miq. in soil and to study their allelopathic activity on Brassica pekinensis (Lour.) Rupr. In seedling tray assays, the rhizosphere soil from G. littoralis continuous monocropping drastically inhibited the growth of B. pekinensis. In Petri dish assays, Methanolic extracts from control soil (CK), soil under first G. littoralis cropping (FS), and continuous cropping (CS) were tested on germination and seedlings growth of B. pekinensis. These extracts inhibited the germination potential, germination rate, shoot height and root length of Brassica pekinensis. GC-MS analysis of the methanolic extracts revealed the presence of dibutyl phthalate (DBP) and 2,4-Di-tert-butylphenol (2,4-DTBP). These allelochemicals inhibited the seedling growth of B. pekinensis in Petri dish assays, and had deleterious effects on photosynthetic system and redox balance. Activities of peroxidase (POD) and catalase (CAT) increased, whereas, superoxide dismutase (SOD) decreased, chlorophyll content was lowered, but hydrogen peroxide (H2O2) and malondialdehyde (MDA) were increased. Our results suggested that under monocropping G. littoralis releases allelochemicals (DBP and 2,4-DTBP) into the soil. [ABSTRACT FROM AUTHOR]