Cinnamate 4-hydroxylase (C4H) is a cytochrome P450-dependent monooxygenase enzyme that catalyzes a key step in phenylpropanoid metabolism in plants. However, there is very limited information on the function of C4H in medicinal plants. In the present study, the C4H gene from the Ferula pseudalliacea genome (named FpC4H) was cloned and characterized. In addition, the expression levels of FpC4H in the roots, stems, leaves, flowers and seeds were investigated via real-time PCR. FpC4H showed the most similarity with C4H proteins from Daucus carota. The results predicted that FpC4H, as well as its orthologs, is an unstable and hydrophilic protein. A high genetic distance was observed between FpC4H and C4H from monocots based on evolutionary analysis. Moreover, a variable region related to the variable function of C4H was detected in conserved domain region of C4H proteins. Protein structure analysis revealed that isoleucine and leucine residues are frequently present in the binding region of FpC4H, and two ion binding regions, cysteine258 and asparagine217, were identified in the 3D structure of FpC4H. Expression analysis revealed that the FpC4H gene is expressed in all organs of F. pseudallicea. A low expression level of FpC4H was recorded in leaves, and a high expression level was observed in flower tissues. Based on the expression profile, FpC4H seems to be linked to a high content of phenolic compounds in flowers.

De novo regeneration of Cannabis sativa L. (cannabis) using tissue culture techniques remains unreliable and infrequent. Conventional methods for the regeneration and transformation of cannabis have not achieved the reliability and replicability needed to be integrated into research and breeding programs. Protoplast systems are effective for gene expression studies, transformation and genome editing technologies, and opens the possibility of somatic hybridization to create interspecific hybrids. To date, leaf-derived protoplast have been isolated for transient gene expression studies, but attempts at protoplast-to-plant regeneration have not been reported. The present study aims to test the efficacy of using a callus culture system, as an abundant source for protoplast isolation and lays the groundwork for a protoplast-to-plant regeneration system. Using hypocotyl-derived callus cultures, which are known to have relatively greater regenerative potential, the efficacy of protoplast isolation and initial cell division were assessed. In this study, the effect of 2-aminoindane-2-phosphonic acid (AIP) in callus culture media and the effect of subculture frequency on protoplast yield were assessed. This study found that inclusion of AIP at 1 mM resulted in a 334% increase in protoplast yield compared with AIP-free medium, representing the first known use of AIP in cannabis tissue culture. Inclusion of AIP led to a 28% decrease in total soluble phenolics and 52% decrease in tissue browning compared to the control medium. Lastly, a two-phase culture system for protoplast regeneration was tested. At a concentration of 2.0×10^5 protoplasts per mL, division was observed, providing the first know report of cell division from cannabis protoplasts and setting the stage for future development of a protoplast-to-plant regeneration system.

The application of melatonin (MT) has been shown to improve the quality during the storage of fruits and vegetables. The primary objective of this study is to investigate the effects of MT on the quality of fresh-cut Gastrodia elata during low temperature (4°C) storage. The results indicate that MT treatment could suppress the respiratory rate and malondialdehyde content of fresh-cut G. elata, while also slowing down the decline in total acidity and total soluble solids. The treatment with MT reduced the superoxide anions and hydrogen peroxide production, inhibited the activity and expression of peroxidase and polyphenol oxidase. Additionally, it led to increased activity and expression of antioxidant-related enzymes, including superoxide dismutase, catalase, ascorbate peroxidase, glutathione reductase, monodehydroascorbate reductase, and dehydroascorbate reductase, while also resulted in elevated levels of ascorbic acid and glutathione. Furthermore, the treatment with MT induced an increase in total phenolic and flavonoid content of fresh-cut G. elata and enhanced the activity and expression of key enzymes involved in phenylpropanoid pathway (phenylalanine ammonia-lyase, cinnamate-4-hydroxylase, 4-coumarate: CoA ligase). In summary, MT enhances the antioxidant capacity by activating both ROS metabolism and phenylpropanoid pathway, thus maintaining the quality of fresh cut G. elata.

To evaluate the anti-obesity effects of Smilax sieboldii (Smilacaceae), we screened methylene chlo-ride (CH2Cl2), ethyl acetate (EtOAc), aqueous-saturated n-butanol, and ethanol (EtOH) extracts of the whole plant at various concentrations to inhibit adipogenesis in adipocytes. The 3T3-L1 cell line with Oil red O staining with the help of fluorometry was used as an indicator of anti-obesity ac-tivity. Bioactivity-guided fractionation of the EtOH extract and subsequent phytochemical inves-tigation of the active CH2Cl2- and EtOAc-soluble fractions resulted in the isolation of 19 secondary metabolites (1–19), including a new α-hydroxy acid derivative (16) and two new lanostane-type triterpenoids (17 and 18). The structures of these compounds were characterized using various spectroscopic methods. All the isolated compounds were screened for adipogenesis inhibition at concentration of 100 μM. Of these, compounds 1, 2, 4-9, 15, and 19 significantly reduced fat ac-cumulation in 3T3-L1 adipocytes, especially compounds 4, 7, 9, and 19 showing 37.05 ± 0.95, 8.60 ± 0.41 15.82 ± 1.23, and 17.73 ± 1.28% lipid content, respectively, at a concentration of 100 μM. These findings provide experimental evidence that isolates from S. sieboldii extracts exert beneficial ef-fects regarding the regulation of adipocyte differentiation.

Chinese pepper rust is a live parasitic fungal disease caused by Coleosporium zanthoxyli, which seriously affects the cultivation and industrial development of Z. armatum. Cultivating and planting resistant cultivars is considered the most economical and environmentally friendly strategy to control this disease. Therefore, the mining of excellent genes for rust resistance and analysis of the mechanism of rust resistance are the key strategies to achieve the targeted breeding of rust resistance. However, there is no relevant report on pepper rust resistance at present. The aim of the present study was to further explore the resistance mechanism of pepper by screening the rust-resistant germplasm resources in the early stage. Combined with the analysis of plant pathology, transcriptomics, and metabolomics, we found that the genes and metabolites related to phenylpropanoid metabolism were highly enriched in resistant varieties after pathogen infection, which indicated that phenylpropanoid metabolism might mediate the resistance of Z. armatum. This finding was further confirmed by real-time quantitative polymerase chain reaction analysis, which revealed that the expression levels of core genes involved in phenylpropane metabolism in disease-resistant varieties were high. In addition, the difference in flavonoid content in the leaves between resistant and susceptible varieties further supported the conclusion that the flavonoid pathway is one of the main pathways involved in resistance formation in Chinese pepper, and MeJA is involved in the formation of resistance. Our research results not only help to better understand the resistance mechanism of Z. armatum rust but also contribute to the breeding and utilization of resistant varieties.

The phenylpropanoid pathway is a major secondary metabolite pathway that helps plants overcome biotic and abiotic stress and produces various by-products that promote human health. Its byproduct, chloroquinic acid (CQA), is a soluble phenolic compound present in many angiosperms. Hy-droxycinnamate-CoA shikimate/quinate transferase(BAHDs superfamily enzyme) is a significant en-zyme that plays a role in accumulating CQA biosynthesis. This study analyzed transcriptome-wide identification of the phenylpropanoid to chloroquinic acid biosynthesis candidate genes in A. spathulifolius flowers and leaves. Transcriptomic analyses of the flowers and leaves showed a differential expression of the PPP and CQA biosynthesis regulated unigenes. An analysis of PPP captive unigenes revealed the following: the major duplication of the key enzyme, PAL, 120 unigenes in leaves and 76 in flowers; the gene encoding C3’H, 169 unigenes in leaves and 140 unigenes in flowers; duplicated unigenes of 4CL, 41 in leaves and 27 in flowers. In addition, C4H unigenes had 12 unigenes in the leaves of A. spathulifolius and four in the flowers. The characterization of the BAHDs superfamily members identified 82 in leaves and 72 in flowers. Among them, phylogenetic analysis showed that five unigenes encoded HQT and three en-coded HCT in A. spathulifolius. The three HQT are common to both leaves and flowers, whereas the two HQT were specialized for leaves. The pattern of HQT synthesis was upregulated in flowers, whereas HCT was expressed strongly in the leaves of A. spathulifolius. Overall, 4CL, C4H, and HQT are expressed strongly in flowers, and caffeic acid and HCT show more expression in leaves. Therefore, CQA biosynthesis occurs in the flowers of A. spathulifolius rather than leaves.