Storage oil hydrolysis during early seedling growth

Storage oil breakdown plays an important role in the life cycle of many plants by providing the carbon skeletons that support seedling growth immediately following germination. This metabolic process is initiated by lipases (EC: 3.1.1.3), which catalyze the hydrolysis of triacylglycerols (TAGs) to release free fatty acids and glycerol. A number of lipases have been purified to near homogeneity from seed tissues and analysed for their in vitro activities. Furthermore, several genes encoding lipases have been cloned and characterised from plants. However, only recently has data been presented to establish the molecular identity of a lipase that has been shown to be required for TAG breakdown in seeds. In this review we briefly outline the processes of TAG synthesis and breakdown. We then discuss some of the biochemical literature on seed lipases and describe the cloning and characterisation of a lipase called SUGAR-DEPENDENT1, which is required for TAG breakdown in Arabidopsis thaliana seeds

INs and OUTs of faces in consciousness: a study of the temporal evolution of consciousness of faces during binocular rivalry

Contents of consciousness change over time. However, the study of dynamics in consciousness has been largely neglected. Aru and Bachmann have recently brought to the attention of scientists dealing with consciousness the relevance of making inquiries about its temporal evolution. Importantly, they also pointed out several experimental questions as guidelines for researchers interested in studying the temporal evolution of consciousness, including the phases of formation and dissolution of content. They also suggested that these two phases could be characterized by asymmetric inertia. The main objective of the present investigation was to approximate the dynamics of these two phases in the context of conscious face perception. To this aim, we tested the time course of content transitions during a binocular rivalry task using face stimuli and asked participants to map their subjective experience of transitions from one content to the other through a joystick. We then computed metrics of joystick velocity linked to content transitions as proxies of the formation and dissolution phases. We found a general phase effect such that the formation phase was slower than the dissolution phase. Furthermore, we observed an effect specific to happy facial expressions, such that their contents were slower to form and dissolve than that of neutral expressions. We further propose to include a third phase of stabilization of conscious content between formation and dissolution

Auxin-Binding Protein 1 is a negative regulator of the SCF(TIR1/AFB) pathway

International audienceAuxin is a major plant hormone that controls most aspects of plant growth and development. Auxin is perceived by two distinct classes of receptors: transport inhibitor response 1 (TIR1, or auxin-related F-box (AFB)) and auxin/indole-3-acetic acid (AUX/IAA) coreceptors, that control transcriptional responses to auxin, and the auxin-binding protein 1 (ABP1), that controls a wide variety of growth and developmental processes. To date, the mode of action of ABP1 is still poorly understood and its functional interaction with TIR1/AFB-AUX/IAA coreceptors remains elusive. Here we combine genetic and biochemical approaches to gain insight into the integration of these two pathways. We find that ABP1 is genetically upstream of TIR1/AFBs; ABP1 knockdown leads to an enhanced degradation of AUX/IAA repressors, independently of its effects on endocytosis, through the SCF TIR1/AFB E3 ubiquitin ligase pathway. Combining positive and negative regulation of SCF ubiquitin-dependent pathways might be a common mechanism conferring tight control of hormone-mediated responses

Suppression of oxidative stress by grape seed supplementation in rats

Polyphenol-rich grape seeds have a beneficial effect on human health. The present study was performed to investigate the effects of grape seeds on antioxidant activities in rats. Male Sprague-Dawley rats were randomly divided into a control diet group (C), a high-fat diet group (HF), a 5% grape seed-supplemented control diet group (G), and a 5% grape seed-supplemented high-fat diet group (HG). Dietary supplementation with grape seeds reduced serum concentrations of lipid peroxides compared with those in the C and HF groups. The hepatic level of lipid peroxides decreased significantly in the grape seed groups compared with that in the C and HF groups. Superoxide dismutase activity in the G group increased significantly compared with that in the C group. Catalase activity tended to be higher by feeding grape seeds. The grape seed diet increased glutathione peroxidase activity in the C group. Glutathione-S-transferase activity increased significantly in the G group compared with that in the C group. Hepatic content of total glutathione increased significantly in the HG group but decreased significantly in the HF group. The ratio of reduced glutathione and oxidized glutathione increased by feeding the grape seed diet. Total vitamin A concentration was significantly higher in HG group than in other groups. Liver tocopherol content of the G and HG groups was significantly higher than that of the control groups. These results suggest that dietary supplementation with grape seeds is beneficial for suppressing lipid peroxidation in high fat-fed rats

A Work Proposal for a Collaborative Study of Magnet Technology for a Future Muon Collider

In this paper we elaborate on the nature and challenges for the magnet systems of a muon collider as presently considered within the scope of the International Muon Collider Collaboration (IMCC). We outline the structure of the work proposed over the coming period of five years to study and demonstrate relevant magnet technology. The proposal, which is part of the overall work planned to establish feasibility of a muon collider, is in direct response to the recent recommendations received from the Laboratories Directors Group (LDG). The plan is to profit from joint activities, within the scope of the IMCC and beyond, implemented through direct and EU-funded contributions.Comment: contribution to Snowmass 202

Antioxidant, Antimicrobial and Antiproliferative Activities of Five Lichen Species

The antioxidative, antimicrobial and antiproliferative potentials of the methanol extracts of the lichen species Parmelia sulcata, Flavoparmelia caperata, Evernia prunastri, Hypogymnia physodes and Cladonia foliacea were evaluated. The total phenolic content of the tested extracts varied from 78.12 to 141.59 mg of gallic acid equivalent (GA)/g of extract and the total flavonoid content from 20.14 to 44.43 mg of rutin equivalent (Ru)/g of extract. The antioxidant capacities of the lichen extracts were determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals scavenging. Hypogymnia physodes with the highest phenolic content showed the strongest DPPH radical scavenging effect. Further, the antimicrobial potential of the lichen extracts was determined by a microdilution method on 29 microorganisms, including 15 strains of bacteria, 10 species of filamentous fungi and 4 yeast species. A high antimicrobial activity of all the tested extracts was observed with more potent inhibitory effects on the growth of Gram (+) bacteria. The highest antimicrobial activity among lichens was demonstrated by Hypogymnia physodes and Cladonia foliacea. Finally, the antiproliferative activity of the lichen extracts was explored on the colon cancer adenocarcinoma cell line HCT-116 by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) viability assay and acridine orange/ethidium bromide staining. The methanol extracts of Hypogymnia physodes and Cladonia foliacea showed a better cytotoxic activity than the other extracts. All lichen species showed the ability to induce apoptosis of HCT-116 cells

Hypoglycaemic and Hypolipidaemic Effects of Withania somnifera Root and Leaf Extracts on Alloxan-Induced Diabetic Rats

Withania somnifera is an important medicinal plant, which is used in traditional medicine to cure many diseases. Flavonoids were determined in the extracts of W. somnifera root (WSREt) and leaf (WSLEt). The amounts of total flavonoids found in WSREt and WSLEt were 530 and 520 mg/100 g dry weight (DW), respectively. Hypoglycaemic and hypolipidaemic effects of WSREt and WSLEt were also investigated in alloxan-induced diabetic rats. WSREt and WSLEt and the standard drug glibenclamide were orally administered daily to diabetic rats for eight weeks. After the treatment period, urine sugar, blood glucose, haemoglobin (Hb), glycosylated haemoglobin (HbA1C), liver glycogen, serum and tissues lipids, serum and tissues proteins, liver glucose-6-phosphatase (G6P) and serum enzymes like aspartate transaminase (AST), alanine transaminase (ALT), acid phosphatase (ACP) and alkaline phosphatase (ALP) levels were determined. The levels of urine sugar, blood glucose, HbA1C, G6P, AST, ALT, ACP, ALP, serum lipids except high density lipoprotein-bound cholesterol (HDL-c) and tissues like liver, kidney and heart lipids were significantly (p < 0.05) increased, however Hb, total protein, albumin, albumin:globulin (A:G) ratio, tissues protein and glycogen were significantly (p < 0.05) decreased in alloxan-induced diabetic rats. Treatment of the diabetic rats with WSREt, WSLEt and glibenclamide restored the changes of the above parameters to their normal level after eight weeks of treatment, indicating that WSREt and WSLEt possess hypoglycaemic and hypolipidaemic activities in alloxan-induced diabetes mellitus (DM) rats

The lipoxygenase-dependent oxygenation of lipid body membranes is promoted by a patatin-type phospholipase in cucumber cotyledons

Oilseed germination is characterized by the mobilization of storage lipids as a carbon and energy source for embryonic growth. In addition to storage lipid degradation in germinating oilseeds via the direct action of a triacylglycerol lipase (TGL) on the storage lipids, a second degradation pathway that is dependent on a specific lipid body trilinoleate 13-lipoxygenase (13-LOX) has been proposed in several plant species. The activity of this specific 13-LOX leads first to the formation of ester lipid hydroperoxides. These hydroperoxy fatty acids are then preferentially cleaved off by a TGL and serve as a substrate for glyoxysomal β-oxidation. As a prerequisite for triacylglycerol (TAG) mobilization, a partial degradation of the phospholipid monolayer and/or membrane proteins of the oil body has been discussed. Evidence has now been found for both processes: partial degradation of the proteins caleosin and oleosin was observed and simultaneously a patatin-like protein together with transient phospholipase (PLase) activity could be detected at the oil body membranes during germination. Moreover, in vitro experiments with isolated oil bodies from mature seeds revealed that the formation of 13-LOX-derived lipid peroxides in lipid body membranes is increased after incubation with the purified recombinant patatin-like protein. These experiments suggest that in vivo the degradation of storage lipids in cucumber cotyledons is promoted by the activity of a specific oil body PLase, which leads to an increased decomposition of the oil body membrane by the 13-LOX and thereby TAGs may be better accessible to LOX and TGL