Quorum Quenchers from Reynoutria japonica in the Battle against Methicillin-Resistant Staphylococcus aureus (MRSA).

Over the past decade, methicillin-resistant Staphylococcus aureus (MRSA) has become a major source of biofilm formation and a major contributor to antimicrobial resistance. The genes that govern biofilm formation are regulated by a signaling mechanism called the quorum-sensing system. There is a need for new molecules to treat the infections caused by dangerous pathogens like MRSA. The current study focused on an alternative approach using juglone derivatives from Reynoutria japonica as quorum quenchers. Ten bioactive compounds from this plant, i.e., 2-methoxy-6-acetyl-7-methyljuglone, emodin, emodin 8-o-b glucoside, polydatin, resveratrol, physcion, citreorosein, quercetin, hyperoside, and coumarin were taken as ligands and docked with accessory gene regulator proteins A, B, and C and the signal transduction protein TRAP. The best ligand was selected based on docking score, ADMET properties, and the Lipinski rule. Considering all these parameters, resveratrol displayed all required drug-like properties with a docking score of -8.9 against accessory gene regulator protein C. To further assess the effectiveness of resveratrol, it was compared with the commercially available antibiotic drug penicillin. A comparison of all drug-like characteristics showed that resveratrol was superior to penicillin in many aspects. Penicillin showed a binding affinity of -6.7 while resveratrol had a score of -8.9 during docking. This was followed by molecular dynamic simulations wherein inhibitors in complexes with target proteins showed stability inside the active site during the 100 ns simulations. Structural changes due to ligand movement inside the cavity were measured in the protein targets, but they remained static due to hydrogen bonds. The results showed acceptable pharmacokinetic properties for resveratrol as compared to penicillin. Thus, we concluded that resveratrol has protective effects against Staphylococcus aureus infections and that it suppresses the quorum-sensing ability of this bacterium by targeting its infectious proteins.

Effects of microscopic testa color and morphologyon the water uptake ability and drought tolerance of germination-stage rapeseed (Brassica napus L.).

Drought is one of the most important abiotic stressors that affect crop yield. Therefore, the aim of the present study was to investigate correlations between germination-stage drought tolerance and the microscopic testa (i.e., seed coat) characteristics (color and papilla morphology) and imbibition abilities of 35 rapeseed (Brassica napus L.) accessions. After 2 h imbibition, seed water uptake (fresh weight increase) was significantly positively correlated with testa hue (HHSB), brightness (BHSB,), blue (BRGB), and lightness (L*), with correlation coefficients of 0.38, 0.34, 0.53, and 0.36, respectively, and significantly negatively correlated with saturation (SHSB), greenness-redness (a*), blueness-yellowness (b*), magenta (M), and yellow components (Y), with correlation coefficients of -0.53, -0.40, -0.53, -0.39, and -0.55, respectively. Furthermore, 5-h seed water uptake was significantly positively correlated with number of papillae (No.P), mean papillae area (APA), the papillae area ratio (PAR), gray value of red channel of papillae, with correlation coefficients of 33, 0.36, 0.43, and 0.43, respectively. Under drought conditions, genotypes with more rapid water absorption exhibited higher germination rates and stronger drought tolerance, and the germination rate and drought tolerance of black-seeded accessions were highest, followed by red-seeded accessions and then yellow-seeded accessions, which exhibited the lowest germination rate and drought tolerance. Germination rate was significantly negatively correlated with BRGB, HHSB, L*, Dg, and Db and significantly positively correlated with SHSB and Y, regardless of drought conditions. At the germination stage, DbTP was negatively correlated with drought tolerance.