Gang Zhang

The APETALA2/ethylene‐responsive factor (AP2/ERF) superfamily plays a central role in plant metabolism, stress responses, and hormone signaling. Rheum officinale Baill. is an important traditional medicinal plant whose roots and rhizomes are rich in anthraquinones and other secondary metabolites. However, the regulatory mechanisms underlying its development and secondary metabolism remain unclear, and systematic analyses of its AP2/ERF family are lacking. This study aimed to characterize the genomic features, expression patterns, and potential functions of the AP2/ERF family in R. officinale . A total of 167 RoAP2/ERF genes were identified, unevenly distributed across 11 chromosomes. Gene family expansion was mainly driven by segmental and tandem duplications, with extensive collinearity observed between R. officinale and related species. Phylogenetic, conserved domain, gene structure, and motif analyses classified these genes into five subfamilies (ERF, dehydration reaction element binding factor; AP2, related to abscisic acid insensitive 3/viviparous 1; and Soloist), with similar sequence characteristics within each subfamily. RNA‐seq analysis revealed tissue‐specific expression patterns, with Cluster 5 genes preferentially expressed in roots and rhizomes. RT‐qPCR of 18 representative genes confirmed their involvement in various signaling pathways. RoERF065 and RoERF079 were exclusively nuclear‐localized and strongly responsive to stress and hormone treatments. Functional assays indicated that RoERF079 acts as a C‐terminal‐dependent transcriptional activator, whereas RoERF065 may function as a repressor due to two EAR motifs. These genes may regulate root and rhizome development and secondary metabolism in R. officinale . This study provides a basis for elucidating the molecular mechanisms of organ development and bioactive compound biosynthesis and identifies candidate genes for molecular breeding.

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.

Melatonin (N-acetyl-5-methoxytryptamine) has been demonstrated to play a significant role in plant stress responses. This study aimed to evaluate the effects of exogenous melatonin (50, 100 and 200 μmol/L) on growth parameters, antioxidant enzyme activity, photosynthetic performance, and aquaporin-related gene expression in licorice (Glycyrrhiza uralensis Fisch.) seedlings under PEG-induced drought stress. The results indicated that drought significantly reduced plant height, root length, leaf mass, and antioxidant enzyme activities of leaves and roots. It also inhibited photosynthesis rate, stomatal conductance (gs), and water use efficiency (WUE), disrupted the potential activity and function of PSII, and decreased water channel protein gene expression. Melatonin treatments were found to mitigate the adverse effects of drought by restoring plant growth attributes and photosynthetic efficiency, decreasing transpiration, increasing water utilization, stomatal conductance, and water channel protein gene expression. Additionally, melatonin treatments increased fluorescence parameters such as actual photochemical efficiency of PSII (ΦPSII), electron transfer rate (ETR) and photochemical quenching (qP), as well as antioxidant enzyme activities. Water conditions are positively correlated with most photosynthetic indicators and significantly associated with the expression of the majority of aquaporin (AQPs) genes. Additionally, melatonin concentration is significantly positively correlated with stomatal limitation (Ls), ΦPSII, ETR, and the expression of the GuTIP1;3 gene in roots. In conclusion, melatonin can protect photosynthetic organs under drought stress, reduce reactive oxygen species (ROS) accumulation, and thus improve the adaptability of seedlings to drought stress.

To explore the bioactive components in Jiawei Xiaoyao Pills (JWXYP) and their mechanisms for alleviating depression-like behaviors. The active compounds, key targets, and pathways of JWXYP were identified using TCMSP and TCMIP databases. Thirty-six SD rats were randomized equally into 6 groups including a control group and 5 chronic unpredictable mild stress (CUMS)-induced depression groups. After modeling, the 5 model groups were treated with daily gavage of normal saline, 1.8 mg/kg fluoxetine hydrochloride (positive control drug), or JWXYP at 1.44, 2.88, and 4.32 g/kg. The depression-like behaviors of the rats were evaluated using behavioral tests, and pathological changes in the liver and hippocampus were examined with HE staining. The biochemical indicators in the serum and brain tissues were detected using ELISA. Serum metabolomics analysis was performed to identify the differential metabolites using OPLS-DA, and gut microbiota changes were analyzed using 16S rDNA sequencing. Network pharmacology revealed that menthone and paeonol in JWXYP were capable of penetrating the blood-brain barrier to regulate inflammatory pathways and protect the nervous system. In the rat models subjected to CUMS, treatment with JWXYP significantly improved body weight loss, sucrose preference and open field activities, reduced liver inflammation, alleviated structural changes in the hippocampal neurons, decreased serum levels of TNF‑α, IL-1β, IL-6 and LBP, and increased 5-HT and VIP concentrations in the serum and brain tissue, and these effects were the most pronounced in the high-dose group. Metabolomics analysis showed changes in such metabolites as indole-3-acetamide and acetyl-L-carnitine in JWXYP-treated rats, involving the pathways for bile acid biosynthesis and amino acid metabolism. 16S rDNA analysis demonstrated increased gut microbiota diversity and increased abundance of Lactobacillus species in JWXYP-treated rats. JWXYP alleviates depression-like symptoms in rats by regulating the neurotransmitters, inhibiting inflammation and oxidation, and modulating gut microbiota.

Stilbene synthase (STS), is a pivotal gene involved in the biosynthesis and regulation of stilbenes compounds, playing a crucial role in plant growth, development and stress adaptation. Meantime, stilbene compounds hold promising prospects of the wide-ranging clinical applications. Rheum officinale contains abundant stilbene compounds, yet the precise regulatory genes governing their biosynthesis remain elusive. In this study, the ORF of RoSTS gene was amplified, yielding a length of 1,140 bp and encoding a protein consisting of 379 amino acids with a relative molecular mass of 41 640.25 Da. The RoSTS protein contained the conserved residues (Cys 164, His 303, and Asn 336), and was closely related to STS of R. palmatum and R. tataricum. Moreover, qRT-PCR analysis revealed that RoSTS had the highest expression in the roots and rhizomes of 2-year-old plants, with significantly up-regulation under MeJA and SA treatments. Subcellular localization analysis showed that RoSTS protein was localized in the nucleus and cell membrane. Furthermore, RoSTS was cloned into pGEX6p-1, expressed in Escherichia coli BL21(DE3), And the purified recombinant protein could catalyze the synthesis of resveratrol from specific substrates in vitro. Overexpression of RoSTS could significantly increase the content of resveratrol in hairy roots of R. officinale, and qRT-PCR analysis showed that the relative expression of RoSTS in transgenic hairy roots was also significantly higher than that of WT. These results indicated that RoSTS might be involved in the stilbenes biosynthesis in R. officinale. Our work may contribute to understanding the mechanism of resveratrol biosynthesis in R. officinale.

Rheum officinale is a prominent traditional medicinal herb in the Chinese Pharmacopeia. Variations in the composition and accumulation of secondary metabolites in R. officinale have been observed to correlate with harvest periods. This study investigated the progressive accumulation of six bioactive compounds in the roots and rhizomes of R. officinale over three growth years. Comparative transcriptome analyses were performed across three developmental stages of both root and rhizome tissues. In the root tissues, 23 differentially expressed genes (DEGs) were observed, including CYP450, WRKY, UGT73C5, WAT1, and XTH15, which displayed significant differential expression patterns. Similarly, 14 DEGs in the rhizome tissues showed significant differential expression, encompassing CYP450, WRKY, and UGT71A15. Short Time-series Expression Miner (STEM) analysis revealed that cluster 10 (1,826 genes) in the root tissues was notably enriched in metabolic processes, predominantly involving WRKY, CYP450, and HSP gene families. In rhizome tissues, cluster 9 (3,301 genes) included numerous gene families, with WRKY, CYP450, and UGT as the top three. Additionally, Weighted Gene Co-expression Network Analysis (WGCNA) was used to construct networks for 3,734 and 1,578 DEGs in root and rhizome tissues, respectively. Hub genes such as WRKY32 and CYP82G1 exhibited robust connectivity with other genes, suggesting their pivotal roles in pharmacopoeia indicator biosynthesis in root tissues. Moreover, CYP76T24, UGT71A15, and WRKY44 were identified as crucial genes in pharmacopoeia indicator biosynthesis in rhizome tissues. Collectively, these comprehensive results underscore the involvement of CYP450 and UGT in the biosynthetic pathways of bioactive compounds in R. officinale.

The mature flesh of Cornus officinalis exhibits a vibrant red color, attributed to its rich anthocyanin content, imparting significant edible and medicinal value. Vibrant colors not only enhance the visual allure of medicinal materials but also maintain a close association with their intrinsic quality. However, the intricate process of pigment formation governing the anthocyanin accumulation in the pericarp of Cornus officinalis remains poorly understood. In this study, we conducted the comprehensive sampling and analysis of pericarp tissues at three distinct developmental stages, employing morphological-structure observation and metabolomic and transcriptomic techniques. Our findings reveal a substantial increase in the anthocyanin accumulation during the transition to the red stage of Cornus officinalis fruit maturation. Metabolomic profiling identified the highest expression levels of Cyanidin-3-O-glucoside and Pelargonidin-3-O-rutinoside during the mature stage, suggesting their association with the red coloration of the fruit. Through RNA sequencing, we identified 25,740 differentially expressed genes (DEGs), including 41 DEGs associated with anthocyanin biosynthesis. The correlation between the DEG expression levels and anthocyanin content was explored, further elucidating the regulatory network. Additionally, we validated the pivotal role of the candidate gene BZ1 in the synthesis of Cyanidin-3-O-glucoside through qRT-PCR, confirming its crucial impact on anthocyanin accumulation. This study provides preliminary insights into anthocyanin accumulation in Cornus officinalis, laying the foundation for the future development of new cultivars with enhanced anthocyanin contents.