WRKY transcription factors constitute one of the largest transcription factor families in plants, and play crucial roles in plant growth and development, defense regulation and stress responses. However, knowledge about this family in maize is limited. In the present study, we identified a drought-induced WRKY gene, ZmWRKY106, based on the maize drought de novo transcriptome sequencing data. ZmWRKY106 was identified as part of the WRKYII group, and a phylogenetic tree analysis showed that ZmWRKY106 was closer to OsWRKY13. The subcellular localization of ZmWRKY106 was only observed in the nucleus. The promoter region of ZmWRKY106 included the C-repeat/dehydration responsive element (DRE), low-temperature responsive element (LTR), MBS, and TCA-elements, which possibly participate in drought, cold, and salicylic acid (SA) stress responses. The expression of ZmWRKY106 was induced significantly by drought, high temperature, and exogenous abscisic acid (ABA), but was weakly induced by salt. Overexpression of ZmWRKY106 improved the tolerance to drought and heat in transgenic Arabidopsis by regulating stress-related genes through the ABA-signaling pathway, and the reactive oxygen species (ROS) content in transgenic lines was reduced by enhancing the activities of superoxide dismutase (SOD), peroxide dismutase (POD), and catalase (CAT) under drought stress. This suggested that ZmWRKY106 was involved in multiple abiotic stress response pathways and acted as a positive factor under drought and heat stress.

Abiotic stress severely influences plant growth and development. MYB transcription factors (TFs), which compose one of the largest TF families, play an important role in abiotic stress responses. We identified 139 soybean MYB-related genes; these genes were divided into six groups based on their conserved domain and were distributed among 20 chromosomes (Chrs). Quantitative real-time PCR (qRT-PCR) indicated that GmMYB118 highly responsive to drought, salt and high temperature stress; thus, this gene was selected for further analysis. Subcellular localization revealed that the GmMYB118 protein located in the nucleus. Ectopic expression (EX) of GmMYB118 increased tolerance to drought and salt stress and regulated the expression of several stress-associated genes in transgenic Arabidopsis plants. Similarly, GmMYB118-overexpressing (OE) soybean plants generated via Agrobacterium rhizogenes (A. rhizogenes)-mediated transformation of the hairy roots showed improved drought and salt tolerance. Furthermore, compared with the control (CK) plants, the clustered, regularly interspaced, short palindromic repeat (CRISPR)-transformed plants exhibited reduced drought and salt tolerance. The contents of proline and chlorophyll in the OE plants were significantly greater than those in the CK plants, whose contents were greater than those in the CRISPR plants under drought and salt stress conditions. In contrast, the reactive oxygen species (ROS) and malondialdehyde (MDA) contents were significantly lower in the OE plants than in the CK plants, whose contents were lower than those in the CRISPR plants under stress conditions. These results indicated that GmMYB118 could improve tolerance to drought and salt stress by promoting expression of stress-associated genes and regulating osmotic and oxidizing substances to maintain cell homeostasis.

Abiotic stresses restrict the growth and yield of crops. Plants have developed a number of regulatory mechanisms to respond to these stresses. WRKY transcription factors (TFs) are plant-specific transcription factors that play essential roles in multiple plant processes, including abiotic stress response. At present, little information regarding drought-related WRKY genes in maize is available. In this study, we identified a WRKY transcription factor gene from maize, named ZmWRKY40. ZmWRKY40 is a member of WRKY group II, localized in the nucleus of mesophyll protoplasts. Several stress-related transcriptional regulatory elements existed in the promoter region of ZmWRKY40. ZmWRKY40 was induced by drought, high salinity, high temperature, and abscisic acid (ABA). ZmWRKY40 could rapidly respond to drought with peak levels (more than 10-fold) at 1 h after treatment. Overexpression of ZmWRKY40 improved drought tolerance in transgenic Arabidopsis by regulating stress-related genes, and the reactive oxygen species (ROS) content in transgenic lines was reduced by enhancing the activities of peroxide dismutase (POD) and catalase (CAT) under drought stress. According to the results, the present study may provide a candidate gene involved in the drought stress response and a theoretical basis to understand the mechanisms of ZmWRKY40 in response to abiotic stresses in maize.

Tremella fuciformis polysaccharide (TFPS), which is the extract of Tremella fuciformis Berk, has previously been demonstrated to exhibit potent anti‑oxidative, anti‑inflammatory and anti‑aging effects. However, the mechanisms underlying these protective and therapeutic effects remain to be elucidated. The aim of the present study was to investigate the protective effects of TFPS on hydrogen peroxide‑induced injury of human skin fibroblasts and to elucidate the aforementioned underlying mechanisms. A hydrogen peroxide‑induced human skin fibroblast injury model was firstly established. MTT and reactive oxygen species (ROS) production assays, in addition to terminal deoxynucleotidyl transferase dUTP nick end labeling, reverse transcription‑quantitative polymerase chain reaction and western blotting, were performed to investigate the protective effects of TFPS. Hydrogen peroxide decreased human skin fibroblast viability with a concurrent increase in ROS generation and cell apoptosis. Treatment with 0‑400 µg/ml TFPS alone for up to 48 h did not result in alteration in cell viability. Notably, TFPS pre‑treatment reduced oxidative stress and cell apoptosis in hydrogen peroxide‑treated skin fibroblasts. In addition, there was profound inhibition of p16, p21, p53 and caspase‑3 expression, and activation of extracellular‑signal regulated kinase and Akt serine/threonine kinase 1, following TFPS pre‑treatment. Furthermore, it was revealed that TFPS additionally protected fibroblasts via the upregulation of SIRT1 expression, and this was abrogated by the SIRT1 inhibitor niacinamide. These results indicated that TFPS alleviated hydrogen peroxide‑induced oxidative stress and apoptosis in skin fibroblasts via upregulation of SIRT1 expression, indicating that TFPS may act as a potential therapeutic agent for oxidative‑stress‑associated skin diseases and aging.

A novel nanofiber material incorporating hyaluronic acid (HA), crude huangshui polysaccharide (cHSP) and polyvinyl alcohol (PVA) were prepared to obtain dry facial masks (PVA/HA/cHSP) via electrospinning. The facial mask was characterized by scanning electron microscopy (SEM), water absorption and retention evaluation, in vitro release study, DPPH and hydroxyl free radical scavenging measurements, red blood cell hemolysis and chick embryo chorioallantoic membrane assay. The results suggested that the fiber mask was densely homogeneous, uniform and well distributed with a diameter 300 %, DPPH and hydroxyl free radical half-inhibitory concentrations of cHSP aqueous solution scavenging were 0.2781 and 1.029 mg/mL, respectively. The PVA/HA/cHSP could retain the antioxidant capacity of cHSP, possessing simultaneous excellent moisture retention and oxidation resistance. Importantly, the mucous membrane irritation experiment indicated that it was mild and safe.

Fibroblasts account for more than 95% of dermal cells maintaining dermal structure and function. However, UVA penetrates the dermis and causes oxidative stress that damages the dermis and accelerates skin aging. Puerarin, the main active ingredient of Puerariae lobata, has been demonstrated to withstand oxidative stress caused by a variety of factors. However, there are limited findings on whether puerarin protects fibroblasts from UVA-induced oxidative stress damage. The effects of puerarin on human skin fibroblasts (HSF) under UVA-induced oxidative stress were investigated in this study. It is found that puerarin upregulates antioxidant enzymes’ mRNA expression level and their content through modulating the KEAP1-Nrf2/ARE signaling pathway, thus improving cell antioxidant capacity and successfully eliminating UVA-induced reactive oxygen species (ROS) and lipid oxidation product malondialdehyde (MDA). Additionally, puerarin blocks the overexpression of human extracellular signal-regulated kinase (ERK), human c-Jun amino-terminal kinase (JNK), and P38, which downregulates matrix metalloproteinase 1 (MMP-1) expression and increases type I collagen (COL-1) expression. Moreover, preliminary research on mouse skin suggests that puerarin can hydrate, moisturize, and increase the antioxidant capacity of skin tissue. These findings suggest that puerarin can protect the skin against photoaging.