Histone Deacetylase Inhibitor, Sodium Butyrate-Induced Metabolic Modulation in Platycodon grandiflorus Roots Enhances Anti-Melanogenic Properties.

While the status of histone acetylation is a critical regulator of chromatin's structure with a significant impact on plant physiology, our understanding of epigenetic regulation in the biosynthesis of active compounds in plants is limited. In this study, Platycodon grandiflorus was treated with sodium butyrate (NaB), a histone deacetylase inhibitor, to investigate the influence of histone acetylation on secondary metabolism. Its treatment with NaB increased the acetylation of histone H3 at lysine 9, 14, and 27 and enhanced the anti-melanogenic properties of P. grandiflorus roots. Through transcriptome and differentially expressed gene analyses, we found that NaB influenced the expression of genes that were involved in both primary and secondary metabolic pathways. In addition, NaB treatment caused the accumulation of polyphenolic compounds, including dihydroquercetin, gallic acid, and 2,4-dihydroxybenzoic acid. The NaB-induced transcriptional activation of genes in the phenylpropanoid biosynthetic pathway influenced the anti-melanogenic properties of P. grandiflorus roots. Overall, these findings suggest the potential of an epigenomic approach to enhance the medicinal qualities of medicinal plants.

Plant Response to Cold Stress: Cold Stress Changes Antioxidant Metabolism in Heading Type Kimchi Cabbage (Brassica rapa L. ssp. Pekinensis).

Cold stress is known as the important yield-limiting factor of heading type Kimchi cabbage (HtKc, Brassica rapa L. ssp. pekinensis), which is an economically important crop worldwide. However, the biochemical and molecular responses to cold stress in HtKc are largely unknown. In this study, we conducted transcriptome analyses on HtKc grown under normal versus cold conditions to investigate the molecular mechanism underlying HtKc responses to cold stress. A total of 2131 genes (936 up-regulated and 1195 down-regulated) were identified as differentially expressed genes and were significantly annotated in the category of "response to stimulus". In addition, cold stress caused the accumulation of polyphenolic compounds, including p-coumaric, ferulic, and sinapic acids, in HtKc by inducing the phenylpropanoid pathway. The results of the chemical-based antioxidant assay indicated that the cold-induced polyphenolic compounds improved the free-radical scavenging activity and antioxidant capacity, suggesting that the phenylpropanoid pathway induced by cold stress contributes to resistance to cold-induced reactive oxygen species in HtKc. Taken together, our results will serve as an important base to improve the cold tolerance in plants via enhancing the antioxidant machinery.

Molecular Cloning and Functional Characterization of Heat Stress-Responsive Superoxide Dismutases in Garlic (Allium sativum L.).

Superoxide dismutases (SODs) are key antioxidant enzymes that can detoxify the superoxide radicals generated by various stresses. Although various plant SODs have been suggested to improve stress tolerance, SODs in garlic, an economically important vegetable grown worldwide, remain relatively unknown. In this study, we found that heat stress strongly induced the activities of Cu/ZnSODs, FeSODs, and MnSODs in garlic leaves. In addition, we cloned four garlic SODs (AsSODs) and suggest that heat stress-increased SOD activity was reflected at least by the induction of these AsSODs. The results of the agro-infiltration assay suggested that the cloned AsSODs encoded functional SOD enzymes belonging to the Cu/ZnSOD and MnSOD families. As a first step toward understanding the enzymatic antioxidant system in garlic plants, our results provide a solid foundation for an in-depth analysis of the physiological functions of the AsSOD family.

UPLC-ESI-Q-TOF-MS-Based Metabolite Profiling, Antioxidant and Anti-Inflammatory Properties of Different Organ Extracts of Abeliophyllum distichum.

Plant extracts have gained more attention as natural therapeutic agents against inflammation characterized by an overproduction of several inflammatory mediators such as reactive oxygen species and pro-inflammatory cytokines. Although Abeliophyllum distichum Nakai is generally known for its ornamental value, recent pharmacological research has demonstrated its potential therapeutic properties. Thus, to further evaluate the applicability of A. distichum in the food, cosmetic, and medical industries, we identified the phytochemicals in three organ extracts (fruits: AF, branches: AB, leaves: AL) of A. distichum and determined their antioxidant and anti-inflammatory activities. Using UPLC-ESI-Q-TOF-MS, a total of 19 compounds, including dendromoniliside D, forsythoside B, isoacteoside, isomucronulatol 7-O-Glucoside, plantamajoside, and wighteone were identified in the A. distichum organ extracts. AB exhibited a strong reducing power, an oxygen radical antioxidant capacity, and radical scavenging values compared with other samples, whereas AL exhibited the best anti-inflammatory properties. Gene expression, western blot, and molecular docking analyses suggested that the anti-inflammatory effect of AL was mediated by its ability to suppress lipopolysaccharide (LPS)-induced production of reactive oxygen species and/or inhibit LPS-stimulated activation of extracellular signal-regulated protein kinases (ERK1/2) in RAW264.7 cells. Collectively, these results indicate that AL is a potential source of phytochemicals that could be used to treat inflammation-associated diseases.