UPLC-ESI-QTOF-MS/MS Analysis of the Phytochemical Compositions From Chaenomeles speciosa (Sweet) Nakai Fruits

Phytochemistry and pharmacology of plants in the genus Chaenomeles

Chaenomeles plants belong to the Rosaceae family and include five species, Chaenomeles speciosa (Sweet) Nakai, Chaenomeles sinensis (Thouin) Koehne, Chaenomeles japonica (Thunb.) Lindl, Chaenomeles cathayensis (Hemsl.) Schneid and Chaenomeles thibetica Yu. Chaenomeles plants are found and cultivated in nearly every country worldwide. China serves as both the origin and distribution hub for the plants in the Chaenomeles genus, and all Chaenomeles species except for C. japonica are indigenous to China. Chaenomeles spp. is a type of edible medicinal plant that has been traditionally used in China to treat various ailments, such as rheumatism, cholera, dysentery, enteritis, beriberi, and scurvy. A variety of chemical constituents have been extracted from this genus, including terpenoids, phenolics, flavonoids, phenylpropanoids and their derivatives, benzoic acid derivatives, biphenyls, oxylipins, and alkaloids. The biological activity of some of these constituents has already been evaluated. Pharmacological investigations have demonstrated that the plants in the genus Chaenomeles exhibit anti-inflammatory, analgesic, antioxidant, antihyperglycemic, antihyperlipidemic, gastrointestinal protective, antitumor, immunomodulatory, antibacterial, antiviral, hepatoprotective, neuroprotective and other pharmacological activities. The objective of this review is to provide a comprehensive and up-to-date summary of the available information on the genus Chaenomeles to serve as a valuable reference for further investigations.

A telomere-to-telomere reference genome provides genetic insight into the pentacyclic triterpenoid biosynthesis in Chaenomeles speciosa

Chaenomeles speciosa (2n = 34), a medicinal and edible plant in the Rosaceae, is commonly used in traditional Chinese medicine. To date, the lack of genomic sequence and genetic studies has impeded efforts to improve its medicinal value. Herein, we report the use of an integrative approach involving PacBio HiFi (third-generation) sequencing and Hi-C scaffolding to assemble a high-quality telomere-to-telomere genome of C. speciosa. The genome comprised 650.4 Mb with a contig N50 of 35.5 Mb. Of these, 632.3 Mb were anchored to 17 pseudo-chromosomes, in which 12, 4, and 1 pseudo-chromosomes were represented by a single contig, two contigs, and four contigs, respectively. Eleven pseudo-chromosomes had telomere repeats at both ends, and four had telomere repeats at a single end. Repetitive sequences accounted for 49.5% of the genome, while a total of 45 515 protein-coding genes have been annotated. The genome size of C. speciosa was relatively similar to that of Malus domestica. Expanded or contracted gene families were identified and investigated for their association with different plant metabolisms or biological processes. In particular, functional annotation characterized gene families that were associated with the biosynthetic pathway of oleanolic and ursolic acids, two abundant pentacyclic triterpenoids in the fruits of C. speciosa. Taken together, this telomere-to-telomere and chromosome-level genome of C. speciosa not only provides a valuable resource to enhance understanding of the biosynthesis of medicinal compounds in tissues, but also promotes understanding of the evolution of the Rosaceae.

Integrated untargeted metabolome, full-length sequencing, and transcriptome analyses reveal insights into the fruit quality at different harvest times of Chaenomeles speciosa

Chaenomeles speciosa fruit is a homologous medicine and food plant with a long history of multiple uses. It could be harvested near maturity and last for a long time. However, the optimal harvest strategy of Chaenomeles speciosa for various uses is currently unavailable. Here, untargeted metabolome at different harvest times during maturation was investigated for the first time, and 896 metabolites, including sugars, organic acids, amino acids, and phenylpropanoids, were identified. Optimal harvesting methods were proposed for different purposes. During the early maturation stages (before 105 days after full bloom), Ch. speciosa fruit could be harvested as Chinesemedicine. Whereas as snacks and food, Ch. speciosa fruit might be harvested at late maturity (after 120 days after full bloom). In addition, the overall network was revealed by integrating full-length Iso-seq and transcriptomics (RNA-seq) to investigate the association between quality-associated metabolites and Chaenomeles speciosa fruit gene expression during maturation. A few putative genes were captured via screening, dissecting and correlation analysis with the quality-associated metabolites (including d-glucose, catechin, gallocatechin, and succinic acid). Overall, in addition to providing a harvesting strategy for food and medicine, we also investigated the metabolism and gene expression pattern of Chaenomeles speciosa fruit during maturation. This comprehensive data and analyses laid the foundation for further investigating potential regulatory mechanisms during harvest and provided a new possibility for its development and utilization.