Metabolomic and transcriptomic analyses reveal grafting-associated trade-offs between yield and flavonoids in Ziziphus jujuba var. spinosa

Ziziphus jujuba var. spinosa, commonly known as 'wild jujube,' is a significant medicinal and edible plant. While the value of its seeds and pulps is well established, the potential of its leaves has been largely neglected. In this study, we determined the contents of basic chemical components-including total flavonoids, total phenolics, and total saponins-in the leaves, pulp, and seeds of Z. jujuba var. spinosa, and we evaluated their antioxidant activities. In addition, widely targeted metabolomics combined with high-performance liquid chromatography (HPLC)-based targeted validation was employed to systematically compare the metabolite profiles. The three organs exhibited distinct metabolic functional differentiation. Leaves displayed the highest contents of total flavonoids, total phenolics, and total saponins, along with the strongest in vitro antioxidant activity. The characteristic accumulation of flavonoid glycosides, such as rutin and isoquercitrin, and of triterpene saponins, such as pedunculagin, may be associated with defense functions. Pulp accumulated significant amounts of soluble sugars and organic acids, such as citric acid, and contained moderate levels of flavonoids. Seeds functioned as a protein reservoir and accumulated C-glycosylated flavonoids and dammarane-type triterpene saponins. KEGG pathway enrichment analysis showed that flavonoid biosynthesis, phenylpropanoid biosynthesis, and terpenoid backbone biosynthesis are the core pathways driving this organ-specific metabolic differentiation. This study systematically suggests, for the first time from a metabolomics perspective, the "defense-dispersal-reserve" functional differentiation pattern among the leaves, pulp, and seeds of Z. jujuba var. spinosa. These findings provide a scientific basis for developing the leaf, a nontraditional organ, as a high-value antioxidant resource and lay a theoretical foundation for comprehensive whole-plant utilization.

Ziziphus jujuba var. spinosa, commonly known as sour jujube, has been utilized for millennia in traditional Chinese medicine and functional foods. This review comprehensively summarizes the phytochemistry, pharmacology, and resource utilization of its multiple medicinal-edible parts, aiming to bridge research gaps and promote integrated applications. A systematic literature search was conducted across PubMed, Web of Science, Google Scholar, and CNKI, using keywords such as "Sour jujube" and "Z. jujuba var. spinosa," covering publications up to December 2024. Phytochemical analysis identified 354 bioactive compounds, including 164 flavonoids and 74 triterpenoids, underlying the plant's broad-spectrum pharmacological activity. The seeds, a well-documented herbal medicine, are used alone, in polyherbal formulations, or as an adjuvant to acupuncture, with sedative-hypnotic effects extensively studied via neurotransmitter regulation, specifically by upregulating GABA receptor expression and inhibiting 5-HT degradation and signaling pathway modulation. Nonseed tissues, such as fruits, leaves, and roots, exhibit underutilized potential due to their high content of antioxidants and nutrients, yet remain understudied, leading to resource waste. This review highlights the need to prioritize research on nonseed parts to maximize their medicinal and nutritional value. The findings provide a scientific basis for advancing sour jujube's applications in healthcare and functional food industries.

ABA-cytokinin crosstalk regulate drought tolerance in Ziziphus jujuba var. spinosa through the phenylpropanoid pathway: insights from physiological and multi-omics integration.

Ziziphus jujuba var. inermis Rehder is an edible fruit-producing species of the Rhamnaceae family. In the present study, we isolated eight triterpenoids (1-8) from the fruits of Z. jujuba var. inermis and evaluated their apoptotic cell-death-inducing activities in human cancer cell lines (A549, PC-3, and MDA-MB-231). The structures of compounds 1-8 were determined by spectroscopic methods. Among these, four isomers of coumaroyl alphitolic acid showed potent cytotoxic activities on these cancer cells: 3-O-cis-p-coumaroyl alphitolic acid (3), 3-O-trans-p-coumaroyl alphitolic acid (4), 2-O-trans-p-coumaroyl alphitolic acid (5), and 2-O-cis-p-coumaroyl alphitolic acid (6). Moreover, compounds 3-6 induced apoptotic cell death in a concentration-dependent manner. We further investigated the apoptosis-inducing effects of compound 4 in PC-3 cells which triggered the cleavage of procaspase-3, procaspase-7, procaspase-8, bid, and PARP. Compound 4 increased both the mitochondrial reactive oxygen species (ROS) production and the phosphorylation of p38 MAPK (mitogen-activated protein kinase), but decreased the mitochondrial membrane potential. Pretreatment with Mito-TEMPO (a specific mitochondrial-targeted antioxidant) or a specific p38 inhibitor (SB203580) attenuated apoptotic cell death triggered by compound 4 which suggests that compound 4 may induce apoptotic cell death in these cancer cells by increasing the mitochondrial ROS production as well as the subsequent p38 MAPK activation. The study findings provide a rational base to use Ziziphus extracts for cancer treatments in traditional oriental medicine.

The photosynthetic and chlorophyll fluorescence parameters were studied in Ziziphus jujuba var. spinosus under different soil water gradients obtained by irrigation and natural water consumption. We used the rectangular hyperbola model, the nonrectangular hyperbola model, the exponential model, and the modified rectangular hyperbola model to fit our data and evaluate them quantitatively. Based on the relationship among the parameters, the effects of the availability of soil water on photosynthesis were elucidated. The results showed that: (1) The relationship between water content and photosynthetic parameters were fitted best by the modified rectangular hyperbola model, followed by the nonrectangular hyperbola model, the exponential model, and the rectangular hyperbola model. The modified rectangular hyperbola model fitted best the maximum net photosynthetic rate (P Nmax) and the light-saturation point (LSP), while the nonrectangular hyperbola model fitted best the dark respiration rate (R D), the apparent quantum yield (AQY), and the light-compensation point (LCP). (2) The main reason for the net photosynthetic rate (P N) decline was that it reached a stomatal limit when the soil relative water content (RWC) was greater than 25% and it reached a nonstomatal limit when the RWC was lesser than 25%. Under these conditions, the photosynthetic apparatus of Z. jujuba was irreversibly damaged. (3) P max, R D, AQY, and LSP increased first and then decreased, while LCP increased contrary to the RWC. The P N light-response parameters reached optimum when the RWC was 56-73%. (4) The quantum yield of PSII photochemistry reached a maximum when RWC was 80%. Nonphotochemical quenching decreased rapidly, and the minimum fluorescence in the dark-adapted state increased rapidly when RWC was lesser than 25%. Under these conditions, PSII was irreversibly damaged. (5) The RWC range of 11-25% resulted in low productivity and low water use efficiency (WUE). The RWC range of 25-56% resulted in moderate productivity and moderate WUE, and the RWC range of 56-80% resulted in high productivity and high WUE. The RWC range of 80-95% resulted in moderate productivity and low WUE. In summary, photosynthesis of Z. jujuba was physiologically adaptable in response to water stress in sand formed from seashells. The photosynthetic and physiological activity was maintained relatively high when the RWC was between 56 and 80%; Z. jujuba seedlings grew well under these conditions.

Investigating soil microbial spatial distribution is essential for understanding ecosystem responses to climate change. Studies on single vegetation types and their influencing factors are limited. We focused on soil samples from Ziziphus jujuba var. spinosa shrublands in the western foothills of the Taihang Mountains. High-throughput sequencing and bioinformatic techniques were used to analyze the diversity and structure of microbial communities. At the same time, soil physicochemical properties and vegetation characteristics were measured to identify the factors driving microbial community variation. The results showed that dominant bacterial and fungal groups generally exhibited a "unimodal" or "U-shaped" distribution pattern along the latitudinal gradient, with both the highest and lowest values occurring in the mid-section of the study area. Bacterial alpha diversity was higher than fungal alpha diversity. Along the latitudinal gradient, bacterial alpha diversity followed a nonlinear cubic trend, peaking in the southern section and reaching a minimum in the northern section. For fungi, richness displayed a U-shaped pattern, Shannon and evenness indices increased linearly, and the Simpson index decreased linearly. Pearson correlation and redundancy analyses indicated that soil total nitrogen, sand content, total carbon, total phosphorus, litter carbon, and leaf water content influenced bacterial community composition. Fungal communities were primarily affected by mean annual precipitation, soil total nitrogen, nitrate nitrogen, silt content, leaf water content, and litter nitrogen. These findings highlight the complex spatial patterns of soil microbial communities in shrublands and reveal key environmental drivers shaping their distribution. Understanding these patterns provides a critical basis for predicting how soil microbial diversity and composition may respond to environmental changes along latitudinal gradients.

Light and soil moisture availability are two important abiotic factors influencing plant growth in an agroforestry system. Different soil moisture and light treatments were applied to examine the combined impact of drought and shade on the morphological plasticity of Vitex negundo var. heterophylla (Chinese chastetree) and Ziziphus jujuba var. spinosa (Spine jujube). We found that the interaction of light and soil moisture was orthogonal in the two species. V. negundo captured irradiance efficiently with relatively long petiole and petiolule, while Z. jujuba maintained higher branches to absorb light than V. negundo. Compared to the seedlings under full sunlight, the palmately compound leaves of V. negundo under low light showed larger specific leaf area (SLA), lower ratio of leaflet length to width and higher leaf mass ratio (leaf biomass to total biomass); in contrast, the simple leaves of Z. jujuba under low light showed larger SLA and ratio of leaf length to petiole length. In both species, drought reduced the branch number, mean internode length of stem, and increased root mass ratio (root biomass to total biomass), but leaf morphology showed little variation to the decreased soil moisture. Between the two species, V. negundo is more shade-tolerant, while Z. jujuba is more drought-tolerant. In an alley cropping system, the spacing can be smaller in the V. negundo-crop system than the Z. jujuba-crop system when soil moisture is adequate. However, the V. negundo-crop system should be managed with more caution under the soil moisture limited conditions.

Ziziphus jujuba var. spinosa (sour jujube) is a traditional medicinal plant with remarkable tolerance to abiotic stresses, particularly salinity. However, the regulatory mechanisms underlying its salt stress tolerance remain unclear. NHX genes play a crucial role in plant adaptation to salt stress by mediating Na+/K+ transport to maintain intracellular ion homeostasis and pH balance. Although the NHX gene family has been characterized in many plant species, its functional characteristics in sour jujube have not yet been systematically investigated. In this study, using Arabidopsis thaliana as a reference, we identified NHX genes in sour jujube through genome-wide analysis and molecular approaches, and systematically analyzed their phylogenetic relationships, chromosomal locations, conserved motifs, gene structures, cis-regulatory elements in promoter regions, and expression patterns under abiotic stresses, particularly salt stress. The results revealed the presence of eight NHX genes distributed across six chromosomes in sour jujube, which were classified into three subfamilies: Vac-class, Endo-class, and PM-class. Members within the same evolutionary clade exhibited high structural conservation in motif composition and gene architecture. Except for the PM-class, all other clades contained amiloride-binding sites (FF(I/L)(Y/F)LFLLPPI). Analysis of cis-regulatory elements indicated that the promoter regions of these genes were enriched with elements related to defense responses, stress adaptation, and phytohormone signaling, further supporting their role in plant environmental adaptation. Additionally, the qRT-PCR analysis showed that most of the ZjNHX genes in both roots and leaves are up-regulated by salt. Notably, ZjNHX1 expression in roots increased approximately 40-fold within 3 h, whereas ZjNHX2 and ZjNHX3 were strongly induced in leaves under prolonged salt exposure. Taken together, this work gives a detailed overview of the ZjNHX genes and their important roles in response to salt stress in sour jujube. Our findings also provide a foundation for further functional characterization of this gene family.

The plant-specific Lateral Organ Boundaries Domain (LBD) transcription factors (TFs) are critical regulators of the expression of genes related to tissue development and stress responses. Sour jujube (Ziziphus jujuba var. spinosa), a stress-tolerant rootstock for jujube cultivation, remains understudied in terms of its LBD gene family. In this study, a genome-wide analysis of the sour jujube genome was performed and 37 ZjLBD genes were identified. These genes were phylogenetically classified into two classes and six subgroups based on evolutionary relationships with Arabidopsis and poplar. These genes were unevenly distributed across 11 chromosomes, with 15 segmental duplication events detected. Upstream TFs of ZjLBDs were predicted and grouped into six interactive networks, revealing that the functions of ZjLBDs may be enriched in stress response, hormone signaling, and tissue development. RNA-seq data demonstrated tissue-specific expression patterns of ZjLBDs, with limited genes highly expressed in fruit. The ZjLBD23 may regulate the development of flowers and white mature fruits, while ZjLBD11, ZjLBD13, ZjLBD22 and ZjLBD28 may be involved in lateral root formation. Analysis of the cis-acting elements, homology relationships and abiotic stress-induced expression levels suggested functional divergence: ZjLBD13, ZjLBD19 and ZjLBD28 may contribute to extreme cold resistance, ZjLBD11, ZjLBD14, ZjLBD33 and ZjLBD35 may be associated with drought tolerance, and ZjLBD9, ZjLBD13 and ZjLBD22 with salt stress adaptation. This study provides critical insights into the biological roles of ZjLBDs and lays a foundation for breeding sour jujube varieties with enhanced stress resilience.

Terpenoids are critical components of plant environmental adaptation mechanisms. They also exhibit significant therapeutic potential in herbal medicine. 3-Hydroxy-3-methylglutaryl coenzyme A reductase (HMGR), a pivotal rate-limiting enzyme governing the initial stage of the mevalonate (MVA) pathway in triterpene saponin biosynthesis, remains uncharacterized in Ziziphus jujuba var. spinosa. Through genome-wide and molecular analysis, we systematically identified ZjHMGR isoforms and revealed differential tissue-specific expression patterns and significant salt stress-responsive regulation across identified isoforms. Our findings reveal three evolutionarily conserved ZjHMGR isoforms with a complete HMG-CoA reductase domain and closely related to Populus trichocarpa. Collinearity analysis revealed two collinear gene pairs, and purifying selection was identified as the primary evolutionary force acting on the ZjHMGR gene family. Cis-acting element analysis revealed that ZjHMGR gene family enriched MYB-related, TC-rich repeats, light- and hormone-responsive elements, suggesting transcriptional regulation by environmental stimuli and phytohormones. Spatiotemporal expression analysis via qRT-PCR revealed differential transcriptional patterns of ZjHMGR members, with pronounced upregulation under ABA, MeJA, and light induction. Saline stress disrupted the growth of wild jujube seedlings while activating ZjHMGR expression alongside other MVA pathway genes. Overexpression of ZjHMGR enhances salt stress resistance in Arabidopsis thaliana. This study lays the foundation for further investigations into the molecular mechanisms of the ZjHMGR gene family concerning saponin biosynthesis, phytohormone interactions, and salt tolerance in wild jujube.

Phosphatidylethanolamine-binding proteins (PEBPs) are known to regulate flowering time and morphogenesis in plants. However, their identification and functions in Ziziphus jujuba var. spinosa remain uncharacterized. In this study, seven ZjPEBP genes were identified and were unevenly distributed across six chromosomes. Phylogenetic analysis classified them into four subfamilies: FT-like, TFL1-like, MFT-like, and SMFT-like. The SMFT-like subfamily likely originated from horizontal gene transfer (HGT) of prokaryotic origin, exhibiting high sequence similarity to bacteria. In contrast, the remaining six members expanded through dispersed duplication events and possess conserved structures. Cis-acting element analysis suggests that ZjPEBP genes may be involved in growth, development, light responsiveness, hormone signaling, and stress adaptation. Reverse transcription quantitative PCR (RT-qPCR) revealed tissue-specific expression patterns among ZjPEBP genes. The key flowering regulators ZjFT and ZjTFL1 exhibited antagonistic expression dynamics during fruit-bearing shoot (FBS) development: ZjFT expression peaked when FBS reached 2-4 mm in length, coinciding with the initial stage of floral bud differentiation, whereas ZjTFL1 maintained low expression levels throughout all developmental stages. After flowering, a clear spatiotemporal expression gradient was observed, with ZjFT expression in basal leaves being significantly higher than in middle and apical leaves. This expression pattern aligned with the basipetal progression of floral organ differentiation. As the basal and middle sections entered the fruit-setting stage, ZjFT expression was markedly downregulated. Under abscisic acid (ABA) treatment, all ZjPEBP genes were significantly induced, suggesting their potential involvement in both flowering regulation and ABA signaling pathways. Notably, ZjSMFT exhibited the mostpronounced response, with expression levels upregulated approximately 400-fold at 24 hours post-treatment. This study provides a systematic characterization of the ZjPEBP gene family in sour jujube, laying a solid foundation for further elucidating the molecular mechanisms of flowering regulation and its potential applications in molecular breeding.

Little information is available about soil particle-size distribution in shell ridge ecosystems. Based on the principle of quality distribution of soil particle size and fractal theory,Periploca sepium Bunge,Ziziphus jujuba var. spinosa Hu and Messerschmidia sibirica Linn. growing on Shell Island,located on the Yellow River Delta,were analyzed in contrast with bare soil to determine the fractal dimensions of soil particles,soil particle-size distribution and soil water physical characteristics,in order to explore the effects of different vegetation types on soil pore structure and hydrological physical characteristics,and the effect of fractal mechanisms of different vegetation types on soil particle composition in shell sand habitats. The results showed that: 1) In shell sand soil,the distribution of soil particles among three typical vegetations was as follows: coarse sand,fine sand,gravel and silt-clay. And the mean value of coarse,fine sand,gravel and silt-clay was 61. 31%,19. 97%,17. 33%,1. 39%,respectively,indicating that grassland and shrub could decrease the particle content of gravel and coarse sand,and improve the content of soil fine sand and silt-clay,which performed well in 0—20cm soil layer. With the vegetation restoration measures,the mean value of fractal dimension of shell sand varied from 1. 5845 to 1. 9157. The sequence of fractal dimension was as follows: Z. jujuba var. spinosa Hu,P. sepium Bunge and Grassland, and the surface soil layer was larger than that in 20—40cm soil layer. Fractal dimension had a very significant positive correlation with silt-clay( r = 0. 940,P0. 01),a significant positive correlation with fine sand( r = 0. 771,P0. 05),and a very significant negative correlation with coarse sand( r =- 0. 947,P 0. 01),but the correlation with gravel was not obvious. 2) The mean value of soil density in 0—40cm of Z. jujuba var. spinosa Hu,P. sepium Bunge and Grassland were lower by 23. 87%,14. 51% and 10. 47%,respectively,compared with bare land( 1. 48 g / cm3); the mean value of total porosity of soil increased by 16. 96%,16. 71%,1. 31%,respectively,compared with bare land( 45. 39%),and the degree of porosity in the surface soil layer was higher than that in 20—40cm soil layer. Fractal dimension had a very significant negative correlation with soil density,and a very significant positive correlation with capillary porosity and total porosity,but there was no significant correlation with non- capillary porosity. In shell sand habitats,the ventilation permeability was better with soil porosity decreasing,fractal dimension as well; but the higher soil-compacting degree,the bigger soil density,fractal dimension was lower. 3) Vegetation restoration measures could well improve pore structure of shell sand surface and the degree of porosity,as well as ventilation,pervious performance. Soil water storage capacity of grasslands and shrub land all performed better in 0—20cm than that in 20—40cm. Under shell sand habitats,fractal dimension had a very significant positive correlation with total water-storage capacity and capillary water-storage capacity, but the correlation with non-capillary water-storage capacity was not obvious. Judging from the fractal characteristics and soil hydrological physical characteristics,we concluded that the sequence of improving the capacity of soil physical properties and soil and water conservation of three typical vegetations in Shell Island was that shrub,was better than grassland,among which,Z. jujuba var. spinosa Hu was better than P. sepium Bunge,and soil layer in 0—20cm than that in 20—40cm.

Intestinal CncC gene activation mediates the sleep-protective effects of Ziziphus jujuba alcohol extract via the gut-brain axis in Drosophila.

Effect of petroleum on decomposition of shrub–grass litters in soil in Northern Shaanxi of China

The seeds of Ziziphus jujuba var. spinosa are a traditional Chinese medicine for treating insomnia, with jujuboside A and jujuboside B as their core bioactive components. However, the biosynthetic pathways and regulatory mechanisms of these triterpenoid saponins remain poorly understood. In this study, we investigated the accumulation patterns of jujube saponins across 10 varieties at 45, 65, and 85 days after flowering (DAF). Integrated transcriptomic and metabolomic analyses revealed 2,040 differentially expressed genes (DEGs) and 1,593 differentially accumulated metabolites (DAMs). Among these, 35 core DEGs were consistently significant across comparisons, enriched in saponin metabolism, monooxygenase activity, and glycosylation processes. A Uridine Diphosphate (UDP)-glucosyltransferase and two CYP450 family members exhibited expression patterns positively correlated with saponin accumulation, showing upregulation during 45 and 65 DAF and suppression by 85 DAF. qRT-PCR validation confirmed their higher expression in high-saponin varieties. Additionally, downregulated stress–response genes in high-saponin varieties suggested a potential link between abiotic stress tolerance and enhanced saponin production. These findings identify key glycosyltransferase and cytochrome P450 genes potentially governing jujuboside biosynthesis, providing critical insights for metabolic engineering and quality improvement of Z. jujuba.