Search Results (3)

Veronicastrum sibiricum (L.) Pennell, a species within the Plantaginaceae family, has a history of traditional application in addressing conditions such as abdominal pain, common cold, sore throat, parotitis, rheumatic discomfort, and snakebite. The plant produces diverse bioactive constituents, including phenylpropanoids, essential oils, flavonoids, and terpenoids. Terpenoids, generated via terpene synthases (TPSs), are of particular interest due to their pharmacological properties. Nevertheless, TPS enzymes in V. sibiricum have not been thoroughly investigated. In this research, a transcriptomic strategy was employed to isolate and profile TPS genes from V. sibiricum. Sequencing of the transcriptome produced 107,929 unigenes, among which 42,976 were functionally annotated using public databases. KEGG pathway examination revealed 264 genes associated with terpenoid metabolism, including 12 putative VsTPS genes harboring characteristic TPS domains. From these, VsTPS1 was successfully cloned. Functional characterization established that VsTPS1 operates as a bifunctional enzyme: in vitro, it catalyzes the conversion of FPP to (E)-nerolidol and, to a lesser extent, GPP to linalool. When expressed transiently in Nicotiana benthamiana, however, only (E)-nerolidol was detected, supporting its cytosolic localization and substrate specificity toward FPP. Accordingly, this sesquiterpene synthase was redesignated VsNES1. Co-expression of VsNES1 with HMGR in N. benthamiana markedly increased (E)-nerolidol yields, illustrating an effective strategy for heterologous production. These findings deepen our understanding of the TPS family in medicinal plant V. sibiricum and enable future biotechnological exploitation of terpenoid production in heterogenous plant cells. Full article

Although selenium nanoparticles (SeNPs) have attracted great attention due to their potential antioxidant activity and low toxicity, the application of SeNPs is still restricted by their poor stability. A combination of polysaccharides and SeNPs is an effective strategy to overcome the limitations. In this study, Polygonatum sibiricum polysaccharide (PSP) was used as a stabilizer to fabricate SeNPs under a simple redox system. Dynamic light scattering, transmission electron microscopy, energy dispersive X-ray, ultraviolet-visible spectroscopy, Fourier transform infrared, and X-ray photoelectron spectrometer were applied to characterize the synthesized PSP-SeNPs. The stability and the antioxidant activity of PSP-SeNPs were also investigated. The results revealed that the zero-valent and well-dispersed spherical PSP-SeNPs with an average size of 105 nm and a negative ζ-potential of −34.9 mV were successfully synthesized using 0.1 mg/mL PSP as a stabilizer. The prepared PSP-SeNPs were stable for 30 days at 4 °C. The decoration of the nanoparticle surface with PSP significantly improved the free radical scavenging ability of SeNPs. Compared to the H₂O₂-induced oxidative stress model group, the viability of PC-12 cells pretreated with 20 μg/mL PSP-SeNPs increased from 56% to 98%. Moreover, PSP-SeNPs exhibited a higher protective effect on the H₂O₂-induced oxidative damage on PC-12 cells and lower cytotoxicity than sodium selenite and SeNPs. In summary, these results suggest the great potential of PSP-SeNPs as a novel antioxidant agent in the food or nutraceuticals area. Full article

Veronicastrum sibiricum is a perennial species distributed in Korea, Japan, Manchuria, China, and Siberia. This study aimed to determine the requirements for germination and dormancy break of V. sibiricum seeds and to classify the kind of seed dormancy. Additionally, its class of dormancy was compared with other Veronicastrum and Veronica species. V. sibiricum seeds were permeable to water and had a mature embryo during seed dispersal. In field conditions, germination was prevented by physiological dormancy, which was, however, relieved by March of the next year, allowing the start of germination when suitable environmental conditions occurred. In laboratory experiments, the seeds treated with 0, 2, 4, 8, and 12 weeks of cold stratification (4 °C) germinated to 0, 79, 75, 72, and 66%, respectively. After the GA₃ treatment (2.887 mM), ≥90% of the seeds germinated during the four incubation weeks at 20/10 °C. Thus, 2.887 mM GA₃ and at least two weeks at 4 °C were effective in breaking physiological dormancy and initiating germination. Therefore, the V. sibiricum seeds showed non-deep physiological dormancy (PD). Previous research, which determined seed dormancy classes, revealed that Veronica taxa have PD, morphological (MD), or morphophysiological seed dormancy (MPD). The differences in the seed dormancy classes in the Veronicastrum-Veronica clade suggested that seed dormancy traits had diverged. The results provide important data for the evolutionary ecological studies of seed dormancy and seed-based mass propagation of V. sibiricum. Full article