Lipid changes after leaf wounding in Arabidopsis thaliana: expanded lipidomic data form the basis for lipid co‐occurrence analysis

A direct‐infusion electrospray ionization triple–quadrupole mass spectrometry method with multiple reaction monitoring (MRM) was employed to measure 264 lipid analytes extracted from leaves of Arabidopsis thaliana subjected to mechanical wounding. The method provided precise measurements with an average coefficient of variation of 6.1%. Lipid classes analyzed comprised galactolipids and phospholipids (including monoacyl molecular species, molecular species with oxidized acyl chains, phosphatidic acids (PAs)), tri‐ and tetra‐galactosyldiacylglycerols (TrGDGs and TeGDGs), head‐group‐acylated galactolipids, and head‐group‐acylated phosphatidylglycerol (acPG), sulfoquinovosyldiacylglycerols (SQDGs), sphingolipids, di‐ and tri‐acylglycerols (DAGs and TAGs), and sterol derivatives. Of the 264 lipid analytes, 254 changed significantly in response to wounding. In general, levels of structural lipids decreased, whereas monoacyl molecular species, galactolipids and phosphatidylglycerols (PGs) with oxidized fatty acyl chains, PAs, TrGDGs, TeGDGs, TAGs, head‐group‐acylated galactolipids, acPG, and some sterol derivatives increased, many transiently. The observed changes are consistent with activation of lipid oxidizing, hydrolyzing, glycosylating, and acylating activities in the wounding response. Correlation analysis of the levels of lipid analytes across individual control and treated plants was used to construct a lipid dendrogram and to define clusters and sub‐clusters of lipid analytes, each composed of a group of lipids which occurred in a coordinated manner. Current knowledge of metabolism supports the notion that observed sub‐clusters comprise lipids generated by a common enzyme and/or metabolically downstream of a common enzyme. This work demonstrates that co‐occurrence analysis, based on correlation of lipid levels among plants, is a powerful approach to defining lipids generated in vivo by a common enzymatic pathway.     

A Luminal Glycoprotein Drives Dose-Dependent Diameter Expansion of the Drosophila melanogaster Hindgut Tube

An important step in epithelial organ development is size maturation of the organ lumen to attain correct dimensions. Here we show that the regulated expression of Tenectin (Tnc) is critical to shape the Drosophila melanogaster hindgut tube. Tnc is a secreted protein that fills the embryonic hindgut lumen during tube diameter expansion. Inside the lumen, Tnc contributes to detectable O-Glycans and forms a dense striated matrix. Loss of tnc causes a narrow hindgut tube, while Tnc over-expression drives tube dilation in a dose-dependent manner. Cellular analyses show that luminal accumulation of Tnc causes an increase in inner and outer tube diameter, and cell flattening within the tube wall, similar to the effects of a hydrostatic pressure in other systems. When Tnc expression is induced only in cells at one side of the tube wall, Tnc fills the lumen and equally affects all cells at the lumen perimeter, arguing that Tnc acts non-cell-autonomously. Moreover, when Tnc expression is directed to a segment of a tube, its luminal accumulation is restricted to this segment and affects the surrounding cells to promote a corresponding local diameter expansion. These findings suggest that deposition of Tnc into the lumen might contribute to expansion of the lumen volume, and thereby to stretching of the tube wall. Consistent with such an idea, ectopic expression of Tnc in different developing epithelial tubes is sufficient to cause dilation, while epidermal Tnc expression has no effect on morphology. Together, the results show that epithelial tube diameter can be modelled by regulating the levels and pattern of expression of a single luminal glycoprotein.     

Disruption of Yarrowia lipolytica biofilms by rhamnolipid biosurfactant

Background

Biosynthesis of nanoparticles has received increasing attention due to the growing need to develop safe, time-effective and environmentally friendly technologies for nano-materials synthesis. This paper reports the one pot green synthesis of silver nanoparticles (AgNPs) using the leaf bud extract of a mangrove plant, Rhizophora mucronata and their antimicrobial effects against aquatic pathogens. Highly stable AgNPs were synthesized by treating the mangrove leaf bud extract with aqueous silver nitrate solution at 15?psi pressure and 121°C for 5 minutes.

Results

The biosynthesized AgNPs were characterized by UV-visible spectrum, at 426?nm. The X-Ray Diffraction (XRD) pattern revealed the face-centered cubic geometry of AgNPs. Fourier Transform Infra Red (FTIR) spectroscopic analysis was carried out to identify the possible biomolecules responsible for biosynthesis of AgNPs from the leaf bud extract. The size and shape of the well-dispersed AgNPs were documented with the help of High Resolution Transmission Electron Microscopy (HRTEM) with a diameter ranged from 4 to 26?nm. However a maximum number of particles were observed at 4?nm in size. The antibacterial effects of AgNPs were studied against aquatic pathogens Proteus spp., Pseudomonas fluorescens and Flavobacterium spp., isolated from infected marine ornamental fish, Dascyllus trimaculatus.

Conclusion

This study reveals that the biosynthesized AgNPs using the leaf bud extract of a mangrove plant (R. mucronata) were found equally potent to synthetic antibiotics. The size of the inhibition zone increases when the concentration of the AgNPs increased and varies according to species.     

Adaptation to abundant low quality food improves the ability to compete for limited rich food in Drosophila melanogaster

The rate of food consumption is a major factor affecting success in scramble competition for a limited amount of easy-to-find food. Accordingly, several studies report positive genetic correlations between larval competitive ability and feeding rate in Drosophila; both become enhanced in populations evolving under larval crowding. Here, we report the experimental evolution of enhanced competitive ability in populations of D. melanogaster previously maintained for 84 generations at low density on an extremely poor larval food. In contrast to previous studies, greater competitive ability was not associated with the evolution of higher feeding rate; if anything, the correlation between the two traits across lines tended to be negative. Thus, enhanced competitive ability may be favored by nutritional stress even when competition is not intense, and competitive ability may be decoupled from the rate of food consumption.     

A dietary colorant crocin mitigates arthritis and associated secondary complications by modulating cartilage deteriorating enzymes,inflammatory mediators and antioxidant status

Articular cartilage degeneration and inflammation are the hallmark of progressive arthritis and is the leading cause of disability in 10–15% of middle aged individuals across the world. Cartilage and synovium are mainly degraded by either enzymatic or non-enzymatic ways. Matrix metalloproteinases (MMPs), hyaluronidases (HAases) and aggrecanases are the enzymatic mediators and inflammatory cytokines and reactive oxygen species being non-enzymatic mediators. In addition, MMPs and HAases generated end-products act as inflammation inducers via CD44 and TLR-4 receptors involved NF-κB pathway. Although several drugs have been used to treat arthritis, numerous reports describe the side effects of these drugs that may turn fatal. On this account several medicinal plants and their isolated molecules have been involved in modern medicine strategies to fight against arthritis. In view of this, the present study investigated the antiarthritic potentiality of Crocin, a dietary colorant carotenoid isolated from stigma of Crocus sativus. Crocin effectively neutralized the augmented serum levels of enzymatic (MMP-13, MMP-3 and MMP-9 and HAases) and non-enzymatic (TNF-α, IL-1β, NF-κB, IL-6, COX-2, PGE₂ and ROS) inflammatory mediators. Further, Crocin re-established the arthritis altered antioxidant status of the system (GSH, SOD, CAT and GST). It also protected the bone resorption by inhibiting the elevated levels of bone joint exoglycosidases, cathepsin-D and tartrate resistant acid phosphatases. Taken together, Crocin revitalized the arthritis induced cartilage and bone deterioration along with inflammation and oxidative damage that could be accredited to its antioxidant nature. Thus, Crocin could be an effective antiarthritic agent which can equally nullify the arthritis associated secondary complication.     

The cytoplasmic C2A domain of synaptotagmin shows sequence specific interaction with its own mRNA

Synaptotagmin-1 (Syt1) is essential in Ca²⁺-dependent neurotransmitter release, but its expression regulation is unknown. Here we report that the cytoplasmic Syt1 fragment forms ribonucleoprotein complex by interacting with the 3′ untranslated region (3^′UTR) of its own mRNA. Two protein-binding domains, GU₁₅ repeat and GUCAAUG, within the Syt 3′UTR and the C2 domains in Syt1, especially C2A, are essential in this ribonucleoprotein complex formation. Furthermore, in in vitro assay the translation efficiency of Syt1 mRNA was downregulated in presence of 3′UTR. These results demonstrate for the fist time that the soluble fraction of Syt1 can interact with its own mRNA in a highly sequence specific manner.     

Molecular architecture of myelinated peripheral nerves is supported by calorie restriction with aging

Peripheral nerves from aged animals exhibit features of degeneration, including marked fiber loss, morphological irregularities in myelinated axons and notable reduction in the expression of myelin proteins. To investigate how protein homeostatic mechanisms change with age within the peripheral nervous system, we isolated Schwann cells from the sciatic nerves of young and old rats. The responsiveness of cells from aged nerves to stress stimuli is weakened, which in part may account for the observed age-associated alterations in glial and axonal proteins in vivo . Although calorie restriction is known to slow the aging process in the central nervous system, its influence on peripheral nerves has not been investigated in detail. To determine if dietary restriction is beneficial for peripheral nerve health and glial function, we studied sciatic nerves from rats of four distinct ages (8, 18, 29 and 38 months) kept on an ad libitum (AL) or a 40% calorie restricted diet. Age-associated reduction in the expression of the major myelin proteins and widening of the nodes of Ranvier are attenuated by the dietary intervention, which is paralleled with the maintenance of a differentiated Schwann cell phenotype. The improvements in nerve architecture with diet restriction, in part, are underlined by sustained expression of protein chaperones and markers of the autophagy–lysosomal pathway. Together, the in vitro and in vivo results suggest that there might be an age-limit by which dietary intervention needs to be initiated to elicit a beneficial response on peripheral nerve health.     

Synthesis of <Emphasis Type="Italic">tert</Emphasis>-butyl (substituted benzamido)phenylcarbamate derivatives: anti-inflammatory activity and docking studies

A series of new tert-butyl 2-(substituted benzamido) phenylcarbamate (4a–4j) were synthesized by the condensation of tert-butyl 2-amino phenylcarbamate (3) with various substituted carboxylic acid in the presence of EDCI and HOBt as coupling reagent, obtain in excellent yields. The structures of all newly synthesized compounds were characterized spectroscopically and evaluated for in vivo anti-inflammatory activity compared to the standard drug, indomethacin, by using the carrageenan-induced rat paw edema protocol. Most of the compounds exhibited a promising anti-inflammatory activity within 9 to 12 h, the percentage of inhibition values ranging from 54.239 to 39.021%. The results revealed that the compounds 4i and 4a exhibited better or equivalent anti-inflammatory activity with the percentage of inhibition of 54.239 and 54.130%, respectively, which was comparable to standard drug. In addition to experimental results, in silico docking studies was used as a tool to verify and expand the experimental outcomes.     

Social convergence of gut microbiomes in vampire bats

The ‘social microbiome’ can fundamentally shape the costs and benefits of group-living, but understanding social transmission of microbes in free-living animals is challenging due to confounding effects of kinship and shared environments (e.g. highly associated individuals often share the same spaces, food and water). Here, we report evidence for convergence towards a social microbiome among introduced common vampire bats, Desmodus rotundus, a highly social species in which adults feed only on blood, and engage in both mouth-to-body allogrooming and mouth-to-mouth regurgitated food sharing. Shotgun sequencing of samples from six zoos in the USA, 15 wild-caught bats from a colony in Belize and 31 bats from three colonies in Panama showed that faecal microbiomes were more similar within colonies than between colonies. To assess microbial transmission, we created an experimentally merged group of the Panama bats from the three distant sites by housing these bats together for four months. In this merged colony, we found evidence that dyadic gut microbiome similarity increased with both clustering and oral contact, leading to microbiome convergence among introduced bats. Our findings demonstrate that social interactions shape microbiome similarity even when controlling for past social history, kinship, environment and diet.     

Optimization of medium constituents and fermentation conditions for the production of L-Glutamic acid by the coimmobilized whole cells of Micrococcus glutamicus and Pseudomonas reptilivora

Statistical experimental design was used to optimize medium constituents and the conditions of fermentation, viz., temperature, pH?and the time of fermentation. Higher yields of L-glutamic acid (37.1?kg/m³) was obtained after optimizing medium components and the conditions of fermentation. The optimal levels of medium components were: 61.5575?kg/m³ glucose, 7.3272?kg/m³ urea and 1.783?μg/dm³ biotin. The optimum productivity was achieved using optimized medium at the fermentation temperature of 33.7?°C, initial pH?7.74, and at the time of fermentation of 58.4?h.