Physiological and biochemical changes in ‘Fuyu’ persimmon buds during dormancy

ABSTRACT: This study identified physiological and biochemical changes in ‘Fuyu’ persimmon buds during dormancy. Branches were collected between March and August 2015. Dormancy was evaluated by biological testing of isolated node cuttings at 25 °C and a photoperiod of 16 h. The variables analyzed were water content; reducing sugar content; respiratory activity; activity of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), guaiacol peroxidase (POD) and polyphenol oxidase (PPO) enzymes; hydrogen peroxide content (H2O2) and lipid peroxidation. At the end of March 2015, the plants were already dormant, and the leaves and fruits present indicated a paradormancy effect. Induction of endodormancy may have occurred in June 2015, when chilling hours (CH) below 7.2 °C and higher CH below 12 °C began to accumulate, which coincided with the period in which there was a decrease in water content and respiratory activity, an increase in reducing sugars, a decrease in SOD, CAT, APX and PPO and an increase in H2O2. After an accumulation of 553 CH below 12 °C, the budburst capacity increased, and the buds presented increased water content, decreased reducing sugars content, increased respiratory activity, low activity in SOD, CAT, APX and POD and high levels of H2O2.

Photothermal Therapy may be a Double-edge Sword by Inducing the Formation of Bacterial Antibiotic Tolerance

Photothermal nanoparticles are thought to be the most potential candidates against infectious disease, by disrupting cell membrane and inhibiting metabolism. However, subpopulation survived with this low-activity state may be endowed...

Antioxidant activity of winter wheat when treated with the biopreparation Nigor++

The influence of stress factors on the plant can lead to deterioration of plant functioning and loss of yield. The use of biological preparations based on plant cell elicitors in the technology of grain cultivation makes it possible to regulate the antioxidant activity of plants under abiotic stress. Treatment with the biopreparation Nigor++ in the tillering phase leads to noticeable changes in the balance of antioxidant substances in winter wheat plants Moskovskaya 39. Repeated treatment of Nigor++ after 16 days in the earing phase reduces AOA by 21.8, and by the flowering phase leads to a drop in this indicator by 51% relative to the tillering phase and by 59% relative to control plants. The use of Nigor++ increases the immune status of plants, reduces the concentration of antioxidant substances or reduces their activity due to the formation of stable complexes with magnesium ions included in BP, as well as binding them to highly active free radicals that occur during autoxidation, converting them to low-activity. Keywords: ANTIOXIDANTS, BIOLOGICAL PRODUCTS, WINTER WHEAT, ANTIOXIDANT ACTIVITY, REACTIVE OXYGEN SPECIES, ELICITORS, BIOFLAVONOIDS

Antibacterial Activity of Salam (Syzygium polyanthum) Leaves 70% Ethanolic Extract on Staphylococcus aureus and Staphylococcus epidermidis

Indonesia has a high diversity of potential medicinal plants, which are the second-largest number of indigenous medicinal plants in the world. Syzygium polyanthum, known as Indonesian Bay Leaf or Salam, easily found, widely used in Indonesia as a spice in cooking and traditional medicine. Salam contains secondary metabolites such as flavonoids, alkaloids, tannins, essential oils, sesquiterpenes, triterpenes, phenols, steroids, and saponins. Staphylococcus aureus and Staphylococcus epidermidis are the main bacteria that cause commensal infection and the most common nosocomial infections. This study aims to know the antibacterial activity of the Salam ethanolic extract against Staphylococcus aureusand Staphylococcus epidermidis bacteria. Salam leaves were extracted by 70% ethanol in the maceration method. Antibacterial activity was conducted by the disk diffusion method. The extract exhibits moderate activity (10.51±0.3 mm) at 75% of concentration and low activity (3.69±0.4 mm) at 100% of concentration against Staphylococcus aureus and Staphylococcus epidermidis respectively. The test showed that salam leaves extract had antibacterial activity against Staphylococcus aureus and Staphylococcus epidermidis.

Evaluation of Site-Diversified, Fully Functionalized Diazirine Probes for Chemical Proteomic Applications

Photoaffinity probes combined with the chemical proteomic platform have emerged as versatile tools for ligand and target discovery. However, photoaffinity probes with retained activity cannot always label the known target, indicating that it is challenging to profile a ligand’s targets based on its photoaffinity probe modified at a single site. Herein, we construct a series of site-diversified probes (P1-P6) of 4-anilinoquinazoline, a scaffold shared by several marketed EGFR-targeted drugs, via attaching a “fully functionalized” diazirine tag to six different sites, respectively. Chemical proteomic analysis revealed that these probes show different proteome-wide profiles and distinct competition patterns by erlotinib. Remarkably, low activity P4 towards EGFR inhibition has better EGFR labelling efficiency than the higher one, P5, which highlights the dominance of labelling accessibility of diazirine over probe affinity. In addition, the integrated analysis of protein targets of site-diversified probes can also help distinguish false positive targets. We anticipate that site-diversification of the probes of a given scaffold is an indispensable strategy to truly harness the power of photoaffinity-based chemoproteomics in drug discovery.

Systemic L-ornithine supplementation specifically increases ovarian putrescine levels during ovulation in mice

In all mammalian species examined thus far, the ovaries produce a burst of ornithine decarboxylase (ODC) and putrescine during ovulation or after application of human chorionic gonadotropin (hCG). Aged mice have significantly reduced levels of this periovulatory ODC and putrescine rise. Putrescine supplementation, in vitro during oocyte maturation or in mouse drinking water during the periovulatory period, reduces egg aneuploidies and embryo resorption, improving fertility of aged mice. These studies suggest that periovulatory putrescine supplementation may be a simple and effective therapy for reproductive aging for women. However, putrescine supplementation is expected to increase widespread tissue putrescine levels, raising concerns of nonspecific and unwanted side effects. Given that ODC is highly expressed in the ovaries during ovulation but otherwise exhibits low activity in most tissues, we hypothesized that periovulatory supplementation of L-ornithine, the substrate of ODC, might be suitable for delivering putrescine specifically to the ovaries. In this study, we have demonstrated that systemic application of L-ornithine via oral gavage or subcutaneous injection increased ovarian putrescine levels; the increase was restricted to animals that had been injected with hCG. Furthermore, L-ornithine specifically increased ovarian putrescine levels without affecting putrescine levels in any other tissues. However, our attempts to improve fertility of aged mice through L-ornithine supplementation in mouse drinking water produced either no effects (1% L-ornithine) or negative impact on fertility (4% ornithine). Our results suggest that it might not be feasible to achieve fertility-enhancing ovarian putrescine levels via L-ornithine supplementation in drinking water without encountering undesired consequences of high dose of exogenous L-ornithine.