[en] Often and in various connotations one can hear or read the following syntagma: “Let’s leave the past in the past - and turn to the future”. Even more frequent and numerous are opposite opinions, e.g. “There is no future without past”, “Future is built on past” or “Remembering our past – reaching for our future”, and many more

[en] Highlights: • SVBV P6 is an RNA silencing suppressor. • SVBV P6 suppresses local RNA silencing triggered by single-stranded but not double-stranded GFP RNAs. • SVBV P6 inhibits systemic spread of RNA silencing. • NLS of the SVBV P6 is critical for suppressing PTGS. • SVBV P6 is also a pathogenicity determinant. RNA silencing is a common mechanism that plays a key role in antiviral defense. To overcome host defense responses, plant viruses encode silencing-suppressor proteins to target one or several key steps in the silencing machinery. Here, we report that the P6 protein encoded by Strawberry vein banding virus (SVBV) is an RNA silencing suppressor through Agrobacterium-mediated co-infiltration assays. SVBV P6 protein can suppress green fluorescent protein (GFP) gene silencing induced by single-stranded RNA but not by double-stranded RNA. The P6 protein can also inhibit systemic silencing of GFP through interfering the systemic spread of GFP silencing signal. Subcellular localization study indicated that P6 protein formed irregular bodies and distributed in both cytoplasm and nucleus of Nicotiana benthamiana cells. Furthermore, deletion analysis indicated that a nuclear localization signal (NLS, aa 402–426) in the P6 protein is responsible for the silencing suppression efficiency. In addition, expression of the P6 protein via a Potato virus X (PVX)-based vectors induced more severe mosaic symptoms in N. benthamiana leaves, and transgenic N. benthamiana plants expressing P6 showed obvious vein yellowing as well as severe mosaic symptoms in leaves. Taken together, our results demonstrates that SVBV P6 is a suppressor of RNA silencing, possibly acting at a upstream step for dsRNA generation.

No abstract available

[en] Bay leaves (Laurus nobilis L.) refers to aromatic leaves which are native to minor regions of Asia. In order to extend the shelf life of the bay leaves its water activity and the surface micro-organisms were reduced using microwave heating at different power densities in the range 32.14 to 142.85 Wg-1. Treatment time at each power level was maintained constant at 150 s. The maximum reduction in water activity and moisture content occurred at highest power density. The heating time-temperature profile was obtained at all power levels. TPC, color change and browning index (BI) of bay leaves were measured in order to determine the effect of microwave treatment on microbial reduction and quality. The highest reduction in TPC was found in leaves heated at 142.85 Wg-1 power density along with acceptable quality parameters of the treated bay leaves. (Author)

[en] Basal leaves frequently senesce before anthesis in high population density crops. This paper evaluates the hypothesis that quantitative and qualitative changes in the light environment associated with a high leaf area index (LAI) trigger leaf senescence in sunflower (Helianthus annuus L.) canopies. Mean leaf duration (LD, time from achievement of maximum leaf area) of leaf 8 was significantly (P < 0.05) reduced from 51 to 19 days as crop population density was increased from 0.47 to 4.76 plants m−2. High compared to low plant population density was associated with earlier reduction in the photosynthetically active radiation (PAR) and red/far-red ratio (R/FR) reaching the target leaf. However the changes in R/FR preceded those in PAR. When the light environment of individual leaves of isolated plants growing under field conditions was manipulated using filters and FR-reflecting mirrors, LD was positively and linearly related with the mean daily PAR (MDR) received in the FR- (no FR enrichment) treatments. FR enrichment of light reaching the abaxial surface of the leaf significantly (P < 0.05) reduced LD by 9 days at intermediate PAR levels with respect to FR-controls, but did not affect LD at the maximum PAR used in these experiments. However, when light reaching both leaf surfaces was enriched with FR, LD (for leaves receiving maximum PAR) was 13 days shorter than that of the FR- control. These results show that basal leaf senescence in sunflower is enhanced both by a decrease in PAR and by a decrease in R/FR. (author)

[en] Highlights: • Green synthesis of AgNPs is using Enicostemma axillare. • Characterization of AgNPs was done by TEM, SEM and XRD. • The synthesized AgNP solution was stable for more than two months. • The method was eco-friendly, benign and cost-effective. In the present article, the facile green synthesis of silver nanoparticles (AgNPs) using aqueous leaf extract of Enicostemma axillare (Lam.) has reported. This is a simple, cost-effective, stable for a long time and reproducible aqueous synthesis method to obtain a self-assembly Ag nanoparticles. The size and shape of Ag nanoparticles were characterized by XRD, TEM, and SEM-EDS. The formation and stability of the reduced silver nanoparticles in the colloidal solution were monitored by UV–Vis spectrophotometer analysis. Zeta potential was confirmed by DLS study. The mean particle diameter of silver nanoparticles was calculated from the TEM, SEM and the size of the particles was measured between 15 and 20 nm. TEM analysis revealed the spherical shape of the particles. Crystalline nature of the nanoparticles in the face-centred cubic structure are confirmed by the peaks in the XRD pattern corresponding to (111), (200), (220) and (311) planes. This study showed the biogenic, environmentally friendly and cost-effective synthesis and characterization of the silver nanoparticles.

[en] The structure constants of an algebra determine a cube called the cubical array associated with the algebra. The permuted indices of the cubical array associated with a finite semifield generate new division algebras. We do not not require that the algebra be finite and ask 'Is it possible to choose a basis for the algebra such any permutation of the indices of the structure constants leaves the algebra unchanged?' What are the associated algebras? Author shows that the property 'weakly quadratic' is invariant under all permutations of the indices of the corresponding cubical array and presents two algebras for which the cubical array is invariant under all permutations of the indices.

[en] Plants form a natural source of key bioactive chemicals equipped with excellent antioxidant and anti-tyrosinase properties. The restorative plant Combretum indicum (C. indicum), which belongs to the Combretaceae family, was widely used in customary treatment in the past. The target of this study is to assess the effects of water as a solvent, traditional extraction strategies (maceration and Soxhlet extraction), and extraction time on C. indicum yield. The total phenolic content (TPC), as well as antioxidant and tyrosinase inhibitory activities, were observed by utilising an ultraviolet-visible spectrophotometer. DPPH radical scavenging was used to determine the antioxidant property, while a mushroom tyrosinase inhibition assay was utilised to evaluate the anti-tyrosinase activity. Maceration carried out for 72 h showed good outcomes for TPC, antioxidant, and anti-tyrosinase activities. The results showed that TPC, antioxidant assay, and anti-tyrosinase activities had a significant linear correlation (p<0.05). It is evident from the study that C. indicum leaves, which contain numerous phytochemicals, are strong antioxidants and tyrosinase inhibitors that can potentially play a significant role in the pharmaceutical and cosmetic industries. (author)

No abstract available

[en] For environmental quality assessment, INAA has been applied for determining chemical elements in small (200 mg) and large (200 g) samples of leaves from 200 trees. By applying the Ingamells' constant, the expected percent standard deviation was estimated in 0.9-2.2% for 200 mg samples. Otherwise, for composite samples (200 g), expected standard deviation varied from 0.5 to 10% in spite of analytical uncertainties ranging from 2 to 30%. Results thereby suggested the expression of the degree of representativeness as a source of uncertainty, contributing for increasing of the reliability of environmental studies mainly in the case of composite samples. (author)