Background: Cinnamomum longepaniculatum (Gamble) N. Chao ex H. W. Li, whose leaves produce essential oils, is a traditional Chinese medicine and economically important tree species. In our study, two C. longepaniculatum varieties that have significantly different essential oil contents and leaf phenotypes were selected as the materials to investigate secondary metabolism. Result: The essential oil content and leaf phenotypes were different between the two varieties. When the results of both transcriptome and metabolomic analyses were combined, it was found that the differences were related to phenylalanine metabolic pathways, particularly the metabolism of flavonoids and terpenoids. The transcriptome results based on KEGG pathway enrichment analysis showed that pathways involving phenylpropanoids, tryptophan biosynthesis and terpenoids significantly differed between the two varieties; 11 DEGs (2 upregulated and 9 downregulated) were associated with the biosynthesis of other secondary metabolites, and 12 DEGs (2 upregulated and 10 downregulated) were related to the metabolism of terpenoids and polyketides. Through further analysis of the leaves, we detected 196 metabolites in C. longepaniculatum. The abundance of 49 (26 downregulated and 23 upregulated) metabolites differed between the two varieties, which is likely related to the differences in the accumulation of these metabolites. We identified 12 flavonoids, 8 terpenoids and 8 alkaloids and identified 4 kinds of PMFs from the leaves of C. longepaniculatum. Conclusions: The combined results of transcriptome and metabolomic analyses revealed a strong correlation between metabolite contents and gene expression. We speculate that light leads to differences in the secondary metabolism and phenotypes of leaves of different varieties of C. longepaniculatum. This research provides data for secondary metabolite studies and lays a solid foundation for breeding ideal C. longepaniculatum plants.

Cinnamomum longepaniculatum essential oil (CLEO) possesses antibacterial, anti-inflammatory, and antioxidant activities. However, CLEO shows volatilization and poor solubility, which limits its application field. In this research, inclusion complexes of β-cyclodextrin (β-CD) with CLEO were produced, and its physicochemical properties were characterized. Response surface methodology was used to obtain optimum preparation conditions. A statistical model was generated to define the interactions among the selected variables. Results show that the optimal conditions were an H₂O/β-CD ratio of 9.6:1 and a β-CD/CLEO ratio of 8:1, with the stirring temperature of 20 °C for the maximal encapsulation efficiency values. The physicochemical properties of CLEO/β-CD inclusion complexes (CLEO/β-CD-IC) were investigated. Fourier transform infrared spectroscopy showed that correlative characteristic bands of CLEO disappeared in the inclusion complex. X-ray diffraction presented different sharp peaks at the diffraction angle of CLEO/β-CD-IC. The thermogravimetric analysis demonstrated the thermal stability of CLEO was enhanced after encapsulation. Tiny aggregates with a smaller size of CLEO/β-CD-IC particles were observed by scanning electron microscopy. The comparison of β-CD, CLEO, and physical mixtures with CLEO/β-CD-IC confirmed the formation of inclusion complexes.

The volatility, instability, and water insolubility of Camphora longepaniculata essential oil (CLEO) limit its practical applications in the food, pharmaceutical, and cosmetics industries. CLEO nanoemulsions (CLNEs) were formulated and characterized to overcome the aforementioned issues. The volatile compounds of CLEO were identified by gas chromatography–mass spectrometry. CLNEs were prepared using EL-40 (5%, w/w) as the surfactant via the high-pressure homogenization method. The formation of nanoemulsions was verified by Fourier transform infrared spectroscopy and transmission electron microscopy. Homogenized nanoemulsions had smaller particle sizes of 39.99 ± 0.47 nm and exhibited enhanced stability. The nanostructured CLEO showed an antibacterial effect against Escherichia coli and Staphylococcus aureus. The antibacterial mechanism was explored through bacterial morphology and intracellular lysate leakage. CLNEs disrupted the structure of bacterial cells and impaired the permeability of cell membranes, resulting in the leakage of bacterial intracellular contents. The nanoemulsions exhibited superior radical scavenging ability compared to the pure oil. Furthermore, evaluations of the cellular safety of the CLNEs demonstrated that the survival rate of exposed HOECs was greater than 90%, with an apoptosis rate of less than 10% in a concentration range. The results demonstrated that nanoemulsification improved the stability, solubility in aqueous media, and bioavailability of CLEO, thereby broadening its potential industrial applications as a natural antibacterial and antioxidant agent.

Abscisic acid (ABA) is a key plant hormone that regulates plant growth and response to stress . Pyrabactin resistance 1-like (PYR/PYL) proteins are ABA receptors involved in the initial steps of ABA signaling. Triticum monococcum L. subsp. aegilopoides is an important germplasm resource for wheat. In this study, we identified 15 PYL genes from T. monococcum L. subsp. aegilopoides and found that they were distributed across five chromosomes. Based on phylogenetic analysis, we classified these genes into three subfamilies. Members of each subfamily have similar gene structures and contain a common motif. Further analysis revealed that the promoters have multiple hormone-related elements. We found 7, 33, and 49 collinear gene pairs in three different ploidy wheat species (T. urartu, T. turgidum and T. aestivum), indicating that PYL genes are relatively conserved during the process of wheat polyploidization. Additionally, interaction networks and miRNA targets were predicted, revealing interactions between PYL proteins and key components of the abscisic acid signaling network. miR9666b-3p may serve as a central factor in PYL involvement in the abscisic acid network. Through RNA-seq analysis and qPCR validation, three genes (TbPYL2, TbPYL5, and TbPYL12) were found to potentially play a role in cold stress. These findings lay the groundwork for further research on PYL genes in T. monococcum L. subsp. aegilopoides.