Genome-wide identification, characterization and transcriptional profile of the SWEET gene family in Dendrobium officinale.

BACKGROUND: Dendrobium officinale Kimura et Migo (D. officinale) is a well-known traditional Chinese medicine with high content polysaccharides in stems. The SWEET (Sugars Will Eventually be Exported Transporters) family is a novel class of sugar transporters mediating sugar translocation among adjacent cells of plants. The expression patterns of SWEETs and whether they are associated with stress response in D. officinale remains uncovered. RESULTS: Here, 25 SWEET genes were screened out from D. officinale genome, most of which typically contained seven transmembrane domains (TMs) and harbored two conserved MtN3/saliva domains. Using multi-omics data and bioinformatic approaches, the evolutionary relationship, conserved motifs, chromosomal location, expression patterns, correlationship and interaction network were further analyzed. DoSWEETs were intensively located in nine chromosomes. Phylogenetic analysis revealed that DoSWEETs were divided into four clades, and conserved motif 3 specifically existed in DoSWEETs from clade II. Different tissue-specific expression patterns of DoSWEETs suggested the division of their roles in sugar transport. In particular, DoSWEET5b, 5c, and 7d displayed relatively high expression levels in stems. DoSWEET2b and 16 were significantly regulated under cold, drought, and MeJA treatment, which were further verified using RT-qPCR. Correlation analysis and interaction network prediction discovered the internal relationship of DoSWEET family. CONCLUSIONS: Taken together, the identification and analysis of the 25 DoSWEETs in this study provide basic information for further functional verification in D. officinale.

A systematic study on the chemical diversity and efficacy of the inflorescence and succulent stem of Cynomorium songaricum.

Cynomorium songaricum is a medicinal, edible, and endangered plant species. Since inflorescences are not considered medicinal parts, their discard causes a waste of resources. To expand the medicinal uses of C. songaricum, we evaluated their chemistry and pharmacology by applying widely targeted metabolomics, network pharmacology, and molecular docking. Widely targeted metabolomics results indicated chemical diversity in C. songaricum with 599 compounds. Among them, 280 compounds were different between the succulent stem and inflorescence. With 218 upregulated compounds, inflorescence has more abundant compounds than the succulent stem, especially pigment compounds such as flavonols, flavones, and flavanones. Moreover, anthocyanin and proanthocyanidin were unique compounds in the inflorescence and succulent stem, respectively. Sixty-five compounds in inflorescence and 18 compounds in succulent stems were found to be associated with atherosclerosis in the network pharmacology analysis. Tests revealed that inflorescence had a stronger anti-atherosclerotic effect than succulent stems. Molecular docking analysis revealed that 30 compounds (29 pigment compounds) in inflorescence and 6 compounds (4 pigment compounds) in succulent stem showed strong binding affinities with three target proteins, namely ALB, MPO, and NOS2, especially amentoflavone, quercetin 7-O-rutinoside, and luteolin 7-O-glucoside (cynaroside). Results demonstrated that the inflorescence is rich in pigment compounds and has a potential anti-atherosclerosis effect. This study provides novel methods and ideas for the sustainable development of endangered medicinal plants.