Jujube (Ziziphus jujuba Mill.) is one of the three traditional woody crop species in China, where it originated from the middle and lower reaches of the Yellow River. Jujube is considered one of the oldest cultivated fruit trees species in the world, as its utilization can be traced back to more than 7000 years ago. The jujube has important nutritional, economic, and ecological values, hence it is well received by both planters and consumers. At present, jujube cultivation has spread to more than 48 countries and provides a pathway for Chinese farmers to produce a lucrative cash crop. Jujube is regarded as a superfruit of the future due to its excellent nutritional profile. Social progress and economic shifts leading to the improvement of living standards influence the value of jujube to consumers, who have gradually shifted toward functional foods, while at the same time, consumer desires and environmental pressures change the breeding goals for new jujube varieties. In this review, we summarize the origin, classification, and historical, as well as modern, uses of jujube. We also provide some advice on the establishment of breeding objectives in this new period of jujube development. This review aims to provide useful references for researchers new to jujube, to guide shareholders in the jujube industry, and to formulate breeding objectives for the modern development of elite jujube cultivars.

Jujube (Ziziphus jujuba Mill.) stands as a pivotal fruit tree with significant economic, ecological, and social value. Recent years have witnessed remarkable strides in multi-omics-based biological research on jujube. This review began by summarizing advancements in jujube genomics. Subsequently, we provided a comprehensive overview of the integrated application of genomics, transcriptomics, and metabolomics to explore pivotal genes governing jujube domestication traits, quality attributes (including sugar synthesis, terpenoids, and flavonoids), and responses to abiotic stress and discussed the transcriptional regulatory mechanisms underlying these traits. Furthermore, challenges in multi-omics research on jujube biological traits were outlined, and we proposed the integration of resources such as pan-genomics and sRNAome to unearth key molecules and regulatory networks influencing diverse biological traits. Incorporating these molecules into practical breeding strategies, including gene editing, transgenic approaches, and progressive breeding, holds the potential for achieving molecular-design breeding and efficient genetic enhancement of jujube.

Plant distant grafting can produce stable genetic variation, which is a new method for germplasm innovation. Two chimeras, peach/apricot (PA) and apricot/peach (AP), were created through two-way grafting between peach and apricot. The leaves, flowers and fruit phenotypes of chimeras were significantly different to self-rooted rootstock. In order to investigate the causes of such changes, transcriptome and proteome integrative analyses were conducted on apricots from these two chimeras. Many differentially expressed genes (DEGs) and differentially expressed proteins (DEPs) that may be connected to the development of grafted apricot hybrids were identified and explored based on function. Moreover, we found 76 genes in forward-grafted PA and 46 in reverse-grafted AP that overlapped both in DEGs and DEPs (DEGs/DEPs) via transcriptome–proteome integrative analysis. Mapping the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway database in PA and AP, the top significant enrichment pathways of DEGs/DEPs included lipid metabolism (fatty acid elongation, cutin, suberine and wax biosynthesis, fatty acid degradation and alpha-linolenic acid metabolism) and carbohydrate metabolism (glycolysis/gluconeogenesis, starch and sucrose metabolism and galactose metabolism), revealing that lipid metabolism and carbohydrate metabolism may play an irreplaceable role in the development of grafted apricot hybrids. Taken together, this work uncovered numerous candidate transcripts and proteins involved in the development of grafted apricot hybrids. The molecular mechanisms provide new insights into this important process in other heterografting hybrids.

Jujube (Ziziphus jujuba Mill.) stands as a pivotal fruit tree with significant economic, ecological, and social value. Recent years have witnessed remarkable strides in multi-omics-based biological re-search on jujube. This review began by summarizing advancements in jujube genomics. Subse-quently, we provided a comprehensive overview of the integrated application of genomics, tran-scriptomics, and metabolomics to explore pivotal genes governing jujube domestication traits, quality attributes (including sugar synthesis, terpenoids, and flavonoids), and responses to abiotic stress, and discussed the transcriptional regulatory mechanisms underlying these traits. Further-more, challenges in multi-omics research on jujube biological traits were outlined, and we pro-posed the integration of resources such as pan-genomics and sRNAome to unearth key molecules and regulatory networks influencing diverse biological traits. Incorporating these molecules into practical breeding strategies, including gene editing, transgenic approaches, and progressive breeding, holds the potential for achieving molecular-design breeding and efficient genetic en-hancement of jujube.

Long-distance transfer of genetic material and metabolites between rootstock and scions is well documented in homo-grafted hybrids but has rarely been reported in genetically-distant grafts where the rootstock and scion belong to different families. In this study, we grafted Vitis vinifera scions onto Schisandra chinensis stocks and obtained 20 vegetative hybrids, Vitis vinifera/Schisandra chinensis (Vs). After 25 years of growth, we found that the phenotypes of the leaves, internodes, and fruits of the Vs hybrids above the graft union resembled an intermediate phenotype between V. vinifera and S. chinensis, and the new traits were stable when propagated vegetatively. We further analyzed genetic differences between Vv plants and Vs hybrids using high-throughput sequencing, while metabolomes were analyzed by liquid chromatography-mass spectrometry (LC-MS). We found a total of 2113 differentially expressed genes (DEGs). GO annotation and KEGG pathway enrichment analysis showed that these DEGs enriched mainly in oxidation-reduction and metabolic processes. Seventy-nine differentially expressed miRNAs (DEMs) containing 27 known miRNAs and 52 novel miRNAs were identified. A degradation analysis detected 840 target genes corresponding to 252 miRNAs, of which 12 DEMs and their corresponding target gene expression levels were mostly negatively correlated. Furthermore, 1188 differential metabolic compounds were identified. In particular, in Vs hybrids, the abundance of the metabolites schizandrin and gomisin as the main medicinal ingredients in S. chinensis were down-regulated and up-regulated, respectively. Our data demonstrated the effects of interfamily grafts on the phenotype, transcript profile and metabolites of the scion, and also provided new insight into the genetic, phenotypic, and metabolic plasticity associated with genetically distant grafted hybrids.