As a kind of orchid plant with both medicinal and ornamental value, Dendrobium officinale has garnered increasing research attention in recent years. The MYB and bHLH transcription factors play important roles in the synthesis and accumulation of anthocyanin. However, how MYB and bHLH transcription factors work in the synthesis and accumulation of anthocyanin in D. officinale is still unclear. In this study, we cloned and characterized one MYB and one bHLH transcription factor, namely, D. officinale MYB5 (DoMYB5) and D. officinaleb bHLH24 (DobHLH24), respectively. Their expression levels were positively correlated with the anthocyanin content in the flowers, stems, and leaves of D. officinale varieties with different colors. The transient expression of DoMYB5 and DobHLH24 in D. officinale leaf and their stable expression in tobacco significantly promoted the accumulation of anthocyanin. Both DoMYB5 and DobHLH24 could directly bind to the promoters of D. officinale CHS (DoCHS) and D. officinale DFR (DoDFR) and regulate DoCHS and DoDFR expression. The co-transformation of the two transcription factors significantly enhanced the expression levels of DoCHS and DoDFR. DoMYB5 and DobHLH24 may enhance the regulatory effect by forming heterodimers. Drawing on the results of our experiments, we propose that DobHLH24 may function as a regulatory partner by interacting directly with DoMYB5 to stimulate anthocyanin accumulation in D. officinale.

β-ketoacyl CoA synthase (KCS) is a key enzyme in the synthesis of long-chain fatty acids. It affects plant stress resistance by regulating the chain length of fatty acid elongation products, the wax deposition in plant epidermis, and the formation of suberization layers. Through a comprehensive, genome-wide analysis, we identified members of the melon KCS (CmKCS) family and characterized their sequence features, phylogenetic relationships, and expression profiles under three abiotic stress conditions, employing bioinformatics tools and methods. Fifteen CmKCSs were identified in the melon genome and found to be unevenly distributed across eight chromosomes. The subcellular localization of most members is located on the cytoplasmic membrane and chloroplasts. The CmKCS family amplifies its members in a tandem repeat manner, which is more closely related to the cucumber KCS and has similar gene functions. Subfamilies I, IV, and VI exhibit variations in conserved domain sequences, which may indicate specific functional differentiation. The promoter region harbors various cis-acting elements related to plant hormones and abiotic stress responses. Among these, the most abundant are elements responsive to abscisic acid, methyl jasmonate, salicylic acid, and anaerobic induction. CmKCS5, CmKCS6, CmKCS10, and CmKCS12 showed high expression in autotoxicity, saline-alkali stress, and microplastic exposure environments. These four CmKCSs may play important roles in melon development and stress response. In conclusion, this study provides a comprehensive analysis of the CmKCS gene family, revealing its potential roles in melon’s response to abiotic stresses and laying a foundation for further functional characterization of these genes in stress tolerance mechanisms.

The red-flowered strawberry is a novel ornamental plant. This study aimed to assess the genetic diversity among ornamental strawberry germplasm resources. In this investigation, 17 red-flowered strawberry germplasms and 1 white-flowered strawberry germplasm were analyzed for genetic diversity and genetic relationships using a combination of phenotypic data, inter-simple sequence repeats (ISSR), and conserved DNA-derived polymorphism (CDDP) molecular markers. The results indicated that the 18 strawberry germplasms exhibited significant variability and genetic diversity at both phenotypic and molecular levels. The clustering results revealed notable differences between phenotypic clustering and molecular marker clustering, while the ISSR and CDDP markers grouped into broadly similar clusters. We further consolidated the ISSR and CDDP marker data to conduct the cluster analysis and population structure analysis of the 18 strawberry germplasms. The cluster analysis classified these germplasms into four clusters at a genetic similarity coefficient of 0.77. The population structure analysis categorized the germplasms into three groups, with 88.89% exhibiting a Q value ≥ 0.6, and 11.11% demonstrating a Q value < 0.6. This finding suggests that the genetic background of the 18 strawberry germplasms is relatively homogeneous. Notably, ‘Summer Breeze-Rose’ and ‘Summer Breeze-Cherry’ possess relatively complex genetic backgrounds (Q < 0.6). Furthermore, the floral, foliar, and plant traits of both germplasms display significant ornamental value and can serve as vital resources for the development and utilization of ornamental strawberries, as well as for the selection and breeding of new varieties.