Biostimulants Derived from Moroccan Seaweeds: Seed Germination Metabolomics and Growth Promotion of Tomato Plant

Polysaccharides extracted from seaweeds can function as plant biostimulants. The aim of this study was to assess the effects of Polysaccharide Enriched Extracts (PEEs) obtained from 17 Moroccan seaweeds, on tomato seed germination and plant growth. Three concentrations (0.02, 0.05 and 0.1 mg mL⁻¹) of PEEs were applied to tomato seeds to evaluate their effect on 3 germination parameters: germination percentage (GP), germination speed (GS) and mean germination time (MGT). Metabolomic analysis by GC–MS was subsequently performed on seedlings. In the second experiment, four PEEs concentrations (0.02, 0.05, 0.1 and 0.2 mg mL⁻¹) were used as foliar spray or as soil application to tomato plants. Their growth parameters (number of leaves, shoot length, fresh and dry weight of stem and roots) and biochemical parameters (chlorophyll a and b) were measured. Results indicated a significant increase of GP and GS associated with a significant reduction of MGT of tomato seeds treated with 0.02 mg mL⁻¹ of PEEs obtained from Gigartina sp., Gigartina pistillata, Chondracanthus acicularis, Gelidium crinale, Schizymenia dubyi, Cystoseira. foeniculacea and Fucus spiralis. Similar results were also obtained by application of higher PEEs concentration (0.1 mg mL⁻¹) extracted from Ulva rigida, Codium tomentosum, Codium decorticatum and Bifurcaria bifurcata. Metabolomic analysis on seedlings detected the presence of some metabolites which could possibly be involved in seed germination enhancement or inhibition. The results of the second experiment showed that the same PEEs cited above at the same concentrations enhanced plant dry weight and chlorophyll a content except Gigartina sp., C. foeniculacea and C. decorticatum. Furthermore, soil application of PEEs was more effective in improving plant growth parameters than foliar application. The study shows the potential of PEEs from Moroccan seaweed to be used as biostimulants for a sustainable agriculture.

     

Reliability and time-of-day effect on measures of change of direction deficit in young healthy physical education students

ABSTRACT

This study aimed to examine the reliability and the time-of-day effect of the 505 change of direction (CoD), 10-m sprint, and change of direction deficit test (CoDD). At two different time of days, 39 young diurnally active physical education male students performed different physical tests: 505 CoD, and sprint tests. Measurements were taken at two separate testing sessions, i.e. in the morning (07:00–08:30 h) and early evening (17:00–18:30 h) in a randomized and counter-balanced setting on nonconsecutive days in 21 of them (21.5 ± 1.5 y of age). The results showed that the 505 CoD test, 10-m sprint, and CoDD performances were a reliable test, and performances were better in the evening the 505 CoD, 10-m sprint, and CoDD testing provided reliable and sensitive scores. In addition, phase 2 showed that CoD, speed, and CoDD are affected by the time of day.     

Structure-based prediction of protein–protein interactions between GhWlim5 Domain1 and GhACTIN-1 proteins: a practical evidence with improved fibre strength

Cotton fibre quality is a multigenic trait. Genetic modification of different genes to achieve high quality fibre is difficult without knowing the mechanism lying behind genes interaction. Based on background knowledge an attempt to explore the potential structural interactions between Gossypium hirsutum Wlim5 domain1 and Gossypium hirsutum ACTIN-1 proteins was done in current study. Sequence features of the LIM domain1 of GhWlim5 protein were identified through multiple sequence alignment analysis, and a phylogenetic tree was built to identify evolutionary relationships between sequences. Conservation indicated the evolutionary importance of side chain residues and the presence of several aliphatic and/or bulky residues, which stabilize the protein core and facilitate packing of zinc fingers. The structures of GhWlim5 domain1 and GhACTIN-1 proteins were modelled and validated through computational methods. Validation of GhACTIN-1 and GhWlim5 domain1 structures indicated good structural quality with 99.7% and 100% of the favoured number of residues in allowed regions and Z-score, within the ranges of − 9.87 and − 4.17, respectively. Docking analysis indicated various possible modes of interaction between these two proteins with favourable binding affinities. Based on our strong binding interaction results between GhWlim5 domain1 and GhACTIN-1 proteins, we further investigated the role of over-expression of GhWlim5 by transformation in cotton plants under fibre specific promoter and transgenic plants displayed significant increases in fibre strength.

     

Correlative Imaging of Motoneuronal Cell Elasticity by Pump and Probe Spectroscopy

Because of their role of information transmitter between the spinal cord and the muscle fibers, motor neurons are subject to physical stimulation and mechanical property modifications. We report on motoneuron elasticity investigated by time-resolved pump and probe spectroscopy. A dual picosecond geometry simultaneously probing the acoustic impedance mismatch at the cell-titanium transducer interface and acoustic wave propagation inside the motoneuron is presented. Such noncontact and nondestructive microscopy, correlated to standard atomic force microscopy or a fluorescent labels approach, has been carried out on a single cell to address some physical properties such as bulk modulus of elasticity, dynamical longitudinal viscosity, and adhesion.     

Characterization of binding kinetics of A2AR to Gαs protein by surface plasmon resonance

Because of their surface localization, G protein-coupled receptors (GPCRs) are often pharmaceutical targets as they respond to a variety of extracellular stimuli (e.g., light, hormones, small molecules) that may activate or inhibit a downstream signaling response. The adenosine A_2A receptor (A_2AR) is a well-characterized GPCR that is expressed widely throughout the human body, with over 10 crystal structures determined. Truncation of the A_2AR C-terminus is necessary for crystallization as this portion of the receptor is long and unstructured; however, previous work suggests shortening of the A_2AR C-terminus from 412 to 316 amino acids (A_2AΔ316R) ablates downstream signaling, as measured by cAMP production, to below that of constitutive full-length A_2AR levels. As cAMP production is downstream of the first activation event—coupling of G protein to its receptor—investigating that first step in activation is important in understanding how the truncation effects native GPCR function. Here, using purified receptor and Gα_s proteins, we characterize the association of A_2AR and A_2AΔ316R to Gα_s with and without GDP or GTPγs using surface plasmon resonance (SPR). Gα_s affinity for A_2AR was greatest for apo-Gα_s, moderately affected in the presence of GDP and nearly completely ablated by the addition of GTPγs. Truncation of the A_2AR C-terminus (A_2AΔ316R) decreased the affinity of the unliganded receptor for Gα_s by ～20%, suggesting small changes to binding can greatly impact downstream signaling.     

Population Dynamics of Intermediate-Host Snails in the White Nile River,Sudan: A Year-Round Observational Descriptive Study

We aimed to explore the population dynamics of snail in 3 sites of the White Nile in Sudan. More specifically, we aimed to investigate the annual patterns of snail populations that act as intermediate hosts of schistosomes and monthly snail infection rates and ecological characteristics presumably related to snail populations. We collected snails for 1 year monthly at 3 different shore sites in the vicinity of El Shajara along the White Nile river in Khartoum State, Sudan. In addition, we measured air and water temperatures, water turbidities, vegetation coverages, and water depths and current speeds. Most of the collected snails were Biomphalaria pfeifferi and Bulinus truncatus. The population densities of snails and their infection rates varied across survey sites. The collected snails liberated S. mansoni and S. haematobium cercariae as well as Amphistome and Echinostome cercariae. Infected snails were found during March–June. The ecological characteristics found to be associated with the absence of snails population were: high turbidity, deep water, low vegetation coverage (near absence of vegetation), high water temperature, and high current speed. To our knowledge, this is the first longitudinal study of the snail population and ecological characteristics in the main basin of the White Nile river.     

Chitosan and silver nanoparticles are attractive auxin carriers: A comparative study on the adventitious rooting of microcuttings in apple rootstocks

Nanocarriers for encapsulation and sustained release of agrochemicals such as auxins have emerged as an attractive strategy to provide enhanced bioavailability and efficacy for improved crop yields and nutrition quality. Here, a comparative study was conducted on the effectiveness of chitosan-as a biopolymeric nanocarrier- and silver-as a metallic nanocarrier- on in vitro adventitious rooting potential of microcuttings in apple rootstocks, for the first time. Auxins indole-3-acetic acid (IAA) and indole-3-butyric acid (IBA) loaded silver (nAg) or chitosan nanoparticles (nChi) were synthesized. Scanning electron microscopy and transmission electron microscopy studies showed the spherical shape of the nanoparticles. The average particle size of IAA-nChi was 167.5 ± 0.1 nm while that of IBA-nChi was 123.2 ± 2.6 nm. The hydrodynamic diameter of the nAg-IAA and nAg-IBA particles were measured as 93.66 ± 5 nm and 71.41 ± 3 nm, respectively. Fourier transform infrared spectroscopy analyses confirmed the encapsulation of IAA or IBA in the chitosan nanoparticles. Meanwhile, the characteristic peaks of IAA or IBA were detected on silver nanoparticles. In-vitro adventitious rooting of microcuttings of Malling Merton 106 (MM 106) was significantly higher both in chitosan and silver nanoparticles loaded with IAA or IBA (91.7%–62.5%) compared to free IAA or IBA applications (50.0%–33.3%), except for 2.0 mg L^–1 IBA (66.7%). However, the application of 2 mg L^–1 IBA and IBA-nChi at all concentrations caused an undesirable large callus development.     

Abutilon indicum Exhibits Anxiolytic and Antidepressant Effects in Mice Models

Doklady Biochemistry and Biophysics - Abutilon indicum Linn (A. indicum) is native to tropical and subtropical zones and traditionally used in ulcer, diabetes, piles, jaundice, gonorrhoea and...     

Eremophilane Sesquiterpenes and Benzene Derivatives from the Endophyte Microdiplodia sp. WGHS5

Three new eremophilane sesquiterpenes phomadecalins G−I ( 1 – 3 ) and two new benzene derivatives microdiplzenes A and B ( 12 and 13 ), together with nine known eremophilane sesquiterpenes ( 4 – 11 and 14 ) were isolated from an endophytic fungus, Microdiplodia sp. WGHS5. Their structures were elucidated by the interpretation of HR-ESI-MS and NMR data; meanwhile, the absolute configurations of new compounds were determined on the base of ECD calculations. All compounds were evaluated for the antimicrobial activities and antiproliferative effect on human gastric cancer cell lines (BGC-823).