Isolation, characterization and application of noble bacteriophages targeting potato common scab pathogen Streptomyces stelliscabiei.

Bacteriophages have emerged as promising alternatives to pesticides for controlling bacterial pathogens in crops. Among these pathogens, Streptomyces stelliscabiei (syn. S. stelliscabiei) is a primary causative agent of potato common scab (PCS), resulting in substantial global economic losses. The traditional management methods for PCS face numerous challenges, highlighting the need for effective and environmentally friendly control strategies. In this study, we successfully isolated three novel bacteriophages, namely Psst1, Psst2, and Psst4, which exhibited a broad host range encompassing seven S. stelliscabiei strains. Morphological analysis revealed their distinct features, including an icosahedral head and a non-contractile tail. These phages demonstrated stability across a broad range of temperatures (20-50°C), pH (pH 3-11), and UV exposure time (80 min). Genome sequencing revealed double-stranded DNA phage with open reading frames encoding genes for phage structure, DNA packaging and replication, host lysis and other essential functions. These phages lacked genes for antibiotic resistance, virulence, and toxicity. Average nucleotide identity, phylogenetic, and comparative genomic analyses classified the three phages as members of the Rimavirus genus, with Psst1 and Psst2 representing novel species. All three phages efficiently lysed S. stelliscabiei in the liquid medium and alleviated scab symptom development and reduced pathogen abundance on potato slices. Furthermore, phage treatments of radish seedlings alleviated the growth inhibition caused by S. stelliscabiei with no disease symptoms. In soil potted experiments, phages significantly reduced disease incidence by 40%. This decrease is attributed to a reduction in pathogen density and the selection of S. stelliscabiei strains with reduced virulence and slower growth rates in natural environments. Our study is the first to report the isolation of three novel phages that infect S. stelliscabiei as a host bacterium. These phages exhibit a broad host range, and demonstrate stability under a variety of environmental conditions. Additionally, they demonstrate biocontrol efficacy against bacterial infections in potato slices, radish seedlings, and potted experiments, underscoring their significant potential as biocontrol agents for the effective management of PCS.

Differential regulation of alternative promoters emerges from unified kinetics of enhancer-promoter interaction.

Many eukaryotic genes contain alternative promoters with distinct expression patterns. How these promoters are differentially regulated remains elusive. Here, we apply single-molecule imaging to quantify the transcriptional regulation of two alternative promoters (P1 and P2) of the Bicoid (Bcd) target gene hunchback in syncytial blastoderm Drosophila embryos. Contrary to the previous notion that Bcd only activates P2, we find that Bcd activates both promoters via the same two enhancers. P1 activation is less frequent and requires binding of more Bcd molecules than P2 activation. Using a theoretical model to relate promoter activity to enhancer states, we show that the two promoters follow common transcription kinetics driven by sequential Bcd binding at the two enhancers. Bcd binding at either enhancer primarily activates P2, while P1 activation relies more on Bcd binding at both enhancers. These results provide a quantitative framework for understanding the kinetic mechanisms of complex eukaryotic gene regulation.

Astragalus polysaccharide regulates brown adipocytes differentiation by miR-6911 targeting Prdm16.

Brown adipose tissue (BAT) is a specialized tissue in mammals related to thermogenesis. The Astragalus polysaccharide (APS) is the major natural active component of Astragalus membranaceus, which has been recognized as one of the most popular herbal medicines worldwide. The role and possible mechanisms of APS on brown adipocytes differentiation is not well defined. Here, we explored the effect of APS on the differentiation of brown adipocytes in C3H10T 1/2 cells. The results showed that APS promoted the differentiation of brown adipocytes and improved insulin sensitivity along with significant increases in the expression of brown adipogenic marker proteins (C/EBPα, C/EBPß, and PPARγ), thermogenesis marker proteins (UCP1, PRDM16, and PGC-1α), and insulin sensitivity marker protein (GLUT4). Meanwhile, the results showed that the amount of the phosphorylation of insulin receptor substrate 1 (p-IRS1) and phospho-AKT (p-AKT) which are critical factors in the insulin signaling pathway was increased without changing the total amount of IRS and AKT. Furthermore, the results of RNA-seq showed that APS altered the expression profiles of various miRNAs, and among which the expression of miR-6911 as a universal regulatory factor was significantly decreased. Importantly, we found that miR-6911 regulated the differentiation of brown adipocytes by targeting PR domain-containing 16 (Prdm16). In addition, after transfection of miR-6911 mimics, compared with the control and inhibitor group, PRDM16 protein expression significantly decreased, which was accompanied by the decrease of PPARγ, UCP1, and PGC-1α. Collectively, our results indicated that APS regulated brown adipocytes differentiation in C3H10T 1/2 cells via miRNA-6911 targeting Prdm16.

Astragalus polysaccharide regulates brown adipogenic differentiation through miR-1258-5p-modulated cut-like homeobox 1 expression.

Astragalus polysaccharide (APS) is the major natural active component of Astragalus membranaceus, which has been recognized as one of the most popular herbal medicines worldwide. Enhancing the formation and function of brown adipose tissue increases energy expenditure and hence may potentially be used against obesity and type 2 diabetes. The aim of the present study was to explore the effect and mechanism of APS on brown adipocyte formation. Mouse C3H10T 1/2 cells were subject to APS, and both proliferation and brown adipogenic differentiation were determined. The results showed that APS exhibits a decreased proliferation ability, which is accompanied by downregulated proliferating cell nuclear antigen, cyclin D1, and cyclin-dependent kinase 4. APS promotes the differentiation of C3H10T 1/2 cells into brown adipocytes and induces the expressions of key brown adipogenic transcriptional factors, including CCAAT/enhancer-binding protein ß, uncoupling protein 1, and PR domain-containing 16. Importantly, APS enables insulin sensitization in brown adipocytes, which may proceed through activation of the canonical phosphatidylinositol-3-kinase (PI3K)/protein kinase B (AKT) signaling pathway and AMP-activated protein kinase (AMPK). Furthermore, the level of cut-like homeobox 1 (CUX1) is positively related to brown adipogenic differentiation, while APS regulates Cux1 expression through interaction with miR-1258-5p. Notably, the promotional effect of APS on brown adipogenic differentiation was abolished by Cux1 knockout. Collectively, our results suggest that APS enhances the differentiation of C3H10T 1/2 cells into brown adipocytes through regulating Cux1 via miR-1258-5p.

Leaf Structural Traits Vary With Plant Size in Even-Aged Stands of Sapindus mukorossi.

Sapindus mukorossi Gaertn., an important oleaginous woody plant, has garnered increasing research attention owing to its potential as a source of renewable energy (biodiesel). Leaf structural traits are closely related to plant size, and they affect the fruit yield and oil quality. However, plant size factors that predominantly contribute to leaf structural traits remain unknown. Therefore, the purpose of this study was to understand the associations between leaf structural traits and plant size factors in even-aged stands of S. mukorossi. Results showed that leaf length (LL) and leaf area (LA) markedly increased with the increasing diameter at breast height (DBH) and tree height (TH), although other leaf structural traits did not show noticeable changes. Difference in slopes also indicated that the degree of effect of plant size factors on leaf structural traits was in the order of TH > DBH. Leaf structural traits showed no systematic variation with crown width (CW). LA was significantly positively correlated with LL, leaf width (LW), LL/LW, and leaf thickness (LT) and was significantly but negatively correlated with leaf tissue density (LTD) and leaf dry mass content (LDMC). Specific leaf area showed a significantly negative correlation with LT, LDMC, and LTD. LTD showed a significantly positive correlation with LDMC, but a negative correlation with LT. The results were critical to understand the variability of leaf structural traits with plant size, can provide a theoretical foundation for further study in the relationship between leaf structural traits and fruit yield, and regulate leaf traits through artificial management measures to promote plant growth and fruit yield.

Neuromyelitis optica spectrum disorder in three generations of a Chinese family.

Neuromyelitis optica spectrum disorder is an inflammatory demyelinating disease that is largely sporadic. Familial disease has been reported in one or two generations, although its basis remains unknown. We report here three subjects meeting diagnostic criteria for NMOSD in one family: a father and son, and the maternal aunt of the father. Anticipation, of 27 years, was apparent in transmission from father to son. Aquaporin-4 antibodies were observed in the aunt but not the father and son, nor in other family members. A putative pathogenic mutation in the NECL2 gene was not found in this pedigree. This first report of NMOSD in three generations of one family underlines the heterogeneity of familial NMOSD.