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Highlights: [•] The Sn addition to Pt0.5/θ-Al2O3 catalysts increased the specific Pt surface area. [•] The Pt0.5Sn0.75 catalyst showed the highest metal dispersion. [•] The optimized Sn/Pt ratio increased with an increase in carbon number of alkane. [•] The Sn addition blocked the cracking sites mainly. [•] Excessive addition of Sn resulted in the deactivation of the catalyst. [ABSTRACT FROM AUTHOR]

Development of the vascular tissues is a dynamic process that integrates extrinsic and intrinsic factors to control vascular tissue formation throughout the plant life cycle. During vascular tissue formation in Arabidopsis roots, radial and longitudinal signals, including nuclear factors and plant hormones, control the developmental processes involved in the specification, differentiation, and maintenance of the correct cell types. SHR, a GRAS transcription factor, has been known to regulate the specification of the stem cell niche and ground tissue identity in the root meristem in a non-cell-autonomous manner. However, the role of SHR in the root vasculature is relatively overlooked, despite localization of its mRNA and protein in the stele. Here, we investigated the role of SHR in the vascular system of the primary root using a reverse genetic approach and detailed phenotypic analysis. A novel, loss-of-function null mutant, shr-6, was isolated in the Columbia background, and vascular patterning was characterized in detail. Our results reveal that shr mutants have developmental defects in both protophloem and protoxylem elements. Our study also suggests that SHR plays a central role in the root vascular system to control patterning processes, possibly regulated by longitudinal and radial signals. [ABSTRACT FROM AUTHOR]

Glycosyltransferases (GTs) play an important role in modulating solubility, stability, bioavailability, and bioactivity of secondary metabolites, such as flavonoids. In Arabidopsis thaliana, at least 120 family 1 uridine diphosphate (UDP)-glycosyltransferases (UGTs) have been predicted. However, little is known about their substrates or their physiological roles in planta. To define the role of UGT73B2 in planta, we first characterized its expression pattern using transgenic Arabidopsis plants carrying the cis-elements of UGT73B2 fused to the GUS reporter. During vegetative phase, its expression was high in embryonic and postembryonic roots, where it may play a physiological role in the glycosylation of flavonoids. Loss of function of UGT73B2 alone or in conjunction with its closest homologs, UGT73B1 and UGT73B3, confers greater tolerance to oxidative stress, whereas overexpression of UGT73B2 increases sensitivity to oxidative stress. In addition, growth phenotypes of mutant and transgenic seedlings correlate well with ROS levels in planta. Our results suggest that the glycosylation of flavonoids by UGT73B2—and/or its closest homologs—modulate the response of plants to oxidative stress. [ABSTRACT FROM AUTHOR]

In this study, we determined the germination response in the seeds of the rare plant Pseudolysimachion pusanensis (Y. N. Lee) Y. N. Lee to different temperatures. P. pusanensis seeds were collected from the Baekdudaegan National Arboretum, South Korea, in November 2019, and dried. Dry seeds were placed at constant and alternating temperatures (5 °C, 10 °C, 15 °C, 20 °C, 25 °C, 30 °C, and 35 °C) to determine their germination percentage (GP). The seeds were exposed to 59 temperature combinations ranging from 5 °C to 43 °C using a thermal gradient plate. The photoperiod was set at 12:12 h (light:dark) and germination assays were performed five times a week. Subsequently, the seed GP and the number of days required to reach 50% of the germination (T50) were determined. The highest final GP was 94.38%, with a T50 value of 9.26 d at 15 °C. However, the mean germination time was 12.5 d at 15 °C, and linear regression using 1/T50 revealed that the base temperature ranged from 2.69 °C to 4.68 °C. These results for P. pusanensis seeds stored in a seed bank provide useful data for the native plants horticulture industry and can also be utilized for storage management. [ABSTRACT FROM AUTHOR]

This study investigated the kind of seed dormancy and seed germination of Gentiana triflora var. japonica (Kusn.) H. Hara for developing a seed propagation method. The seeds were collected in October 2020 from plants at Mt. Sobaeksan, Korea. In a water imbibition experiment, seed weights increased by >101.9% of their initial masses over 12 h. Effects of incubation temperature (5, 15, 20, 25, 15/6, or 25/15 °C), cold stratification period (5 °C; 0, 4, 8, or 12 weeks), and gibberellic acid (GA3; 0, 10, 100, or 1000 mg∙L−1) and potassium nitrate treatment (KNO3; 0, 1000, 2000, or 4000 mg∙L−1) on seed germination were investigated to characterize seed dormancy. These seeds exhibited underdeveloped embryos during seed dispersal. The seeds failed to reach the final germination of 15.0% after treatment at 5, 15, 20, 25, 15/6, or 25/15 °C. After cold stratification for 8 weeks, the germination increased dramatically by >90.0% compared to that at 0 weeks. After the GA3 treatment, the germination reached >80.0% within 5 days. The final germination was 90.0% in the 100 mg∙L−1 GA3 treatment group. However, the KNO3 treatment had no effect on seed germination. Therefore, the G. triflora var. japonica seeds exhibited non-deep simple morphophysiological dormancy. [ABSTRACT FROM AUTHOR]

Interferon-gamma (IFN-γ) was found to increase in the synovial fluid of patients with rheumatoid arthritis (RA) and osteoarthritis (OA). However, few studies have been conducted to elucidate the role of IFN-γ in cartilage metabolism and regeneration. In this study, we investigated whether cartilage regeneration is driven by interferon-stimulated gene 15 (ISG15) under the control of IFN-γ. IFN-γ significantly increased ITS-induced chondrogenic differentiation of ATDC5 cells. Knockdown of IFN-γ receptor (IFN-γR) inhibited IFN-γ-induced chondrogenic differentiation and reduced ACAN and Col II expression. In addition, ISG15 expression was highly elevated in response to IFN-γ, whereas its expression was downregulated by knockdown of IFN-γR, indicating that ISG15 is closely related to IFN-γ signaling. Furthermore, chondrogenic differentiation and expression of ACAN and Col II were significantly reduced following knockdown of ISG15 in ATDC5 cells despite the presence of IFN-γ. ISGylation of cellular proteins found in chondrogenic differentiated cells was related to activation of IFN-γ signaling. In addition, ISG15/ISGylation was significantly observed in the regenerated cartilage tissue 7 days after FTCI of young mice compared with sham control. Our findings showed that upregulation of ISG15 and/or ISGylation of cellular proteins may play a critical role in cartilage regeneration through activation of IFN-γ signaling. • IFN-γ signal increases chondrogenic differentiation and ISG15 expression. • IFN-γ receptor or ISG15 silencing inhibits chondrogenic differentiation. • ISGylation of proteins increases in cartilage regeneration post-injury. [ABSTRACT FROM AUTHOR]