Seed longevity is controlled by metacaspases.

To survive extreme desiccation, seeds enter a period of quiescence that can last millennia. Seed quiescence involves the accumulation of protective storage proteins and lipids through unknown adjustments in protein homeostasis (proteostasis). Here, we show that mutation of all six type-II metacaspase (MCA-II) proteases in Arabidopsis thaliana disturbs proteostasis in seeds.

Unusual vitamin E profile in the oil of a wild African oil palm tree ( Jacq.) enhances oxidative stability of provitamin A.

Introduction: The African oil palm ( Jacq.) is the predominant oil crop in the world. In addition to triacylglycerols, crude palm oil (CPO) extracted from the mesocarp of the fruits, contains high amounts of provitamin A (carotenes) and vitamin E (tocochromanols).

Plasticity of the Arabidopsis leaf lipidome and proteome in response to pathogen infection and heat stress.

Plants must cope with a variety of stressors during their life cycle, and the adaptive responses to these environmental cues involve all cellular organelles. Among them, comparatively little is known about the contribution of cytosolic lipid droplets (LDs) and their core set of neutral lipids and associated surface proteins to the rewiring of cellular processes in response to stress. Here, we analyzed the changes that occur in the lipidome and proteome of Arabidopsis (Arabidopsis thaliana) leaves after pathogen infection with Botrytis cinerea or Pseudomonas syringae, or after heat stress.

Vitamin E biofortification: enhancement of seed tocopherol concentrations by altered chlorophyll metabolism.

Homogentisate Phytyltransferase () catalyzes condensation of homogentisate (HGA) and phytyl diphosphate (PDP) to produce tocopherols, but can also synthesize tocotrienols using geranylgeranyl diphosphate (GGDP) in plants engineered for deregulated HGA synthesis. In contrast to prior tocotrienol biofortification efforts, engineering enhanced tocopherol concentrations in green oilseeds has proven more challenging due to the integral role of chlorophyll metabolism in supplying the PDP substrate. This study show that RNAi suppression of coupled with overexpression increases tocopherol concentrations by >two-fold in Arabidopsis seeds.

Tocopherol and phylloquinone biosynthesis in chloroplasts requires the phytol kinase VITAMIN E PATHWAY GENE5 (VTE5) and the farnesol kinase (FOLK).

Chlorophyll degradation causes the release of phytol, which is converted into phytyl diphosphate (phytyl-PP) by phytol kinase (VITAMIN E PATHWAY GENE5 [VTE5]) and phytyl phosphate (phytyl-P) kinase (VTE6). The kinase pathway is important for tocopherol synthesis, as the Arabidopsis (Arabidopsis thaliana) vte5 mutant contains reduced levels of tocopherol. Arabidopsis harbors one paralog of VTE5, farnesol kinase (FOLK) involved in farnesol phosphorylation.

PHD finger proteins function in plant development and abiotic stress responses: an overview.

The plant homeodomain (PHD) finger with a conserved Cys4-His-Cys3 motif is a common zinc-binding domain, which is widely present in all eukaryotic genomes. The PHD finger is the "reader" domain of methylation marks in histone H3 and plays a role in the regulation of gene expression patterns. Numerous proteins containing the PHD finger have been found in plants.

The Bacterial G Signal Transduction Inhibitor FR900359 Impairs Soil-Associated Nematodes.

The cyclic depsipeptide FR900359 (FR) is derived from the soil bacterium Chromobacterium vaccinii and known to bind G proteins of mammals and insects, thereby abolishing the signal transduction of their G protein-coupled receptors, a process that leads to severe physiological consequences. Due to their highly conserved structure, G family of proteins are a superior ecological target for FR producing organisms, resulting in a defense towards a broad range of harmful organisms. Here, we focus on the question whether bacteria like C.

Analysis of isoprenyl-phosphates by liquid chromatography-mass spectrometry.

Isoprenoids in plants are synthesized following the plastidial methylerythritol-4-phosphate (MEP) pathway or the mevalonate pathway localized to the cytosol and peroxisomes. Isoprenyl-diphosphates (isoprenyl-PP) are important intermediates for the synthesis of chlorophyll, carotenoids, sterols, and other isoprenoids in plants. The quantification of isoprenyl-PP is challenging due to the amphipathic structure, the low abundance, and the susceptibility to hydrolysis during extraction and storage.

Lack of a protective effect of the Tmem106b "protective SNP" in the Grn knockout mouse model for frontotemporal lobar degeneration.

Genetic variants in TMEM106B are a common risk factor for frontotemporal lobar degeneration and the most important modifier of disease risk in patients with progranulin (GRN) mutations (FTLD-GRN). TMEM106B is encoding a lysosomal transmembrane protein of unknown molecular function. How it mediates its disease-modifying function remains enigmatic.

Modulating Expression Levels of TCP Transcription Factors by Volatiles-An Allelopathic Tool to Influence Leaf Growth?

Peppermint (Mentha x piperita) is a species with inhibitory allelopathic properties due to its high amounts of terpenes. Recent studies have disclosed dosage dependent growth promotion or defense reactions in plants when facing appropriate amounts of Mentha bouquet terpenes. These positive effects could be of interest for agricultural applications.

Roles of Abscisic Acid and Gibberellins in Stem/Root Tuber Development.

Root and tuber crops are of great importance. They not only contribute to feeding the population but also provide raw material for medicine and small-scale industries. The yield of the root and tuber crops is subject to the development of stem/root tubers, which involves the initiation, expansion, and maturation of storage organs.

Polar lipid characterization and description of sp. nov., isolated from high CO-containing atmosphere and emended descriptions of the genus , and the species , , , , , , and .

Modified atmosphere (MA) packaging plays an important role in improving food quality and safety. By using different gas mixtures and packaging materials the shelf life of fresh produce can significantly be increased. A Gram-negative-staining, rod-shaped, orange-pigmented strain DH-B6, has been isolated from MA packed raw pork sausage (20% CO, 80% O).

Two AMP-Binding Domain Proteins from Involved in Import of Exogenous Fatty Acids.

Arbuscular mycorrhizal fungi (AMF) colonize roots, where they provide nutrients in exchange for sugars and lipids. Because AMF lack genes for cytosolic fatty acid de novo synthase (FAS), they depend on host-derived fatty acids. AMF colonization is accompanied by expression of specific lipid genes and synthesis of -2 monoacylglycerols (MAGs).

Exogenous fatty acids affect membrane properties and cold adaptation of Listeria monocytogenes.

Listeria monocytogenes is a food-borne pathogen that can grow at very low temperatures close to the freezing point of food and other matrices. Maintaining cytoplasmic membrane fluidity by changing its lipid composition is indispensable for growth at low temperatures. Its dominant adaptation is to shorten the fatty acid chain length and, in some strains, increase in addition the menaquinone content.

Stress memory responses and seed priming correlate with drought tolerance in plants: an overview.

Environmental-friendly techniques based on plant stress memory, cross-stress tolerance, and seed priming help sustainable agriculture by mitigating negative effects of dehydration stress. The frequently uneven rainfall distribution caused by global warming will lead to more irregular and multiple abiotic stresses, such as heat stress, dehydration stress, cold stress or the combination of these stresses. Dehydration stress is one of the major environmental factors affecting the survival rate and productivity of plants.

2-Hydroxy-phytanoyl-CoA lyase (AtHPCL) is involved in phytol metabolism in Arabidopsis.

During chlorophyll degradation, large amounts of the isoprenoid alcohol phytol are released. The pathway of phytol catabolism has been studied in humans, because chlorophyll is part of the human diet, but little is known for plants. In humans, phytanoyl-CoA derived from phytol is degraded via α-oxidation by phytanoyl-CoA hydroxylase (PAHX) and 2-hydroxy-phytanoyl-CoA lyase (HPCL).

Differential Regulation of NAPDH Oxidases in Salt-Tolerant and Salt-Sensitive .

Reactive oxygen species (ROS) signalling is crucial in modulating stress responses in plants, and NADPH oxidases (NOXs) are an important component of signal transduction under salt stress. The goal of this research was to investigate whether the regulation of NOX-dependent signalling during mild and severe salinity differs between the halophyte and the glycophyte . Gene expression analyses showed that salt-induced expression patterns of two NOX genes, and , varied between the halophyte and the glycophyte.

Synthesis of the unusual lipid bis(monoacylglycero)phosphate in environmental bacteria.

The bacterial membrane is constantly remodelled in response to environmental conditions and the external supply of precursor molecules. Some bacteria are able to acquire exogenous lyso-phospholipids and convert them to the corresponding phospholipids. Here, we report that some soil-dwelling bacteria have alternative options to metabolize lyso-phosphatidylglycerol (L-PG).

sp. nov., a new species isolated from pork steak packed under modified atmosphere.

Species belonging to the genus have been isolated from environments such as soil, water and plant tissues. Many strains are known for their capability of degrading aromatic molecules and producing extracellular polymers. A Gram-stain-negative, strictly aerobic, motile, red-pigmented, oxidase-negative, catalase-positive, rod-shaped strain, designated DH-S5, has been isolated from pork steak packed under CO-enriched modified atmosphere.

24(R, S)-Saringosterol - From artefact to a biological medical agent.

Enhancing the cholesterol turnover in the brain via activation of liver x receptors can restore memory in a mouse model for Alzheimer's disease. The edible Asian brown alga Sargassum fusiforme (Hijiki) contains high amounts of oxysterols such as (3β, 24ξ)-stigmasta-5, 28-dien-3, 24-diol (24[R, S]-saringosterol) that are a potent liver x receptor agonists. We aimed to find native European seaweed species with contents of 24(R, S)-saringosterol that are comparable to those found in Sargassum fusiforme.

Studying Lipid-Protein Interactions Using Protein-Lipid Overlay and Protein-Liposome Association Assays.

The study of lipid-protein interactions is crucial for understanding reactions of proteins involved in lipid metabolism, lipid transport, and lipid signaling. Different detection methods can be employed for the identification of lipid-binding interactions. Isothermal titration calorimetry (ITC) and surface plasmon resonance (SPR) spectroscopy enable real-time monitoring of lipid protein interactions and provide thermodynamic parameters of the interacting partners.

Structural Analysis of Glycosylglycerolipids Using NMR Spectroscopy.

Glycosylglycerolipids are essential components of plant and bacterial membranes. These lipids exert central roles in physiological processes such as photosynthesis in plants or to maintain membrane stability in bacteria. They are composed of a glycerol backbone esterified with two fatty acids at the sn-1 and sn-2 positions, and carbohydrate moieties connected via a glycosidic bond at the sn-3 position.

Direct Infusion Mass Spectrometry for Complex Lipid Analysis.

Direct infusion or "shotgun" mass spectrometry provides a fast strategy to measure different classes of lipids, combining rapid analysis and short idle time. In contrast to liquid chromatography-mass spectrometry (LC-MS), the lipids are infused into the mass spectrometer without prior separation by liquid chromatography. Ions are separated in the quadrupole of a tandem mass spectrometer, and after collision-induced dissociation fragments are quantified relative to internal standards in the third quadrupole or in the time-of-flight mass analyzer of a triple quadrupole or quadrupole time of flight (Q-TOF) mass spectrometer.

Lipid Analysis by Gas Chromatography and Gas Chromatography-Mass Spectrometry.

Gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) represent powerful tools for the quantitative and structural analysis of plant lipids. Here, we outline protocols for the isolation, separation, and derivatization of plant lipids for subsequent GC and GC-MS analysis. Plant lipids are extracted with organic solvents and separated according to their polarity by thin-layer chromatography or solid phase extraction.

Thin-Layer Chromatography.

Lipid extracts from plants represent a mixture of polar membrane lipids and nonpolar lipids. The main constituents of the polar lipid fraction are glycerolipids, that is, galactolipids, sulfolipid, and phospholipids. In addition, betaine lipids are found in pteridophytes, bryophytes, and algae.