Membrane fluidity control by the Magnaporthe oryzae acyl-CoA binding protein sets the thermal range for host rice cell colonization.

Following leaf cuticle penetration by specialized appressorial cells, the devastating blast fungus Magnaporthe oryzae grows as invasive hyphae (IH) in living rice cells. IH are separated from host cytoplasm by plant-derived membranes forming an apoplastic compartment and a punctate biotrophic interfacial complex (BIC) that mediate the molecular host-pathogen interaction. What molecular and cellular processes determine the temperature range for this biotrophic growth stage is an unanswered question pertinent to a broader understanding of how phytopathogens may cope with environmental stresses arising under climate change.

From sensing to acclimation: The role of membrane lipid remodeling in plant responses to low temperatures.

Low temperatures pose a dramatic challenge to plant viability. Chilling and freezing disrupt cellular processes, forcing metabolic adaptations reflected in alterations to membrane compositions. Understanding the mechanisms of plant cold tolerance is increasingly important due to anticipated increases in the frequency, severity, and duration of cold events.

Exploring cotton SFR2's conundrum in response to cold stress.

Cotton is an important agricultural crop to many regions across the globe but is sensitive to low-temperature exposure. The activity of the enzyme SENSITIVE TO FREEZING 2 (SFR2) improves cold tolerance of plants and produces trigalactosylsyldiacylglycerol (TGDG), but its role in cold sensitive plants, such as cotton remains unknown. Recently, it was reported that cotton SFR2 produced very little TGDG under normal and cold conditions.

Rhythmic lipid and gene expression responses to chilling in panicoid grasses.

Chilling stress threatens plant growth and development, particularly affecting membrane fluidity and cellular integrity. Understanding plant membrane responses to chilling stress is important for unraveling the molecular mechanisms of stress tolerance. Whereas core transcriptional responses to chilling stress and stress tolerance are conserved across species, the associated changes in membrane lipids appear to be less conserved, as which lipids are affected by chilling stress varies by species.

All members of the Arabidopsis DGAT and PDAT acyltransferase families operate during high and low temperatures.

The accumulation of triacylglycerol (TAG) in vegetative tissues is necessary to adapt to changing temperatures. It has been hypothesized that TAG accumulation is required as a storage location for maladaptive membrane lipids. The TAG acyltransferase family has five members (DIACYLGLYCEROL ACYLTRANSFERSE1/2/3 and PHOSPHOLIPID:DIACYLGLYCEROL ACYLTRANSFERASE1/2), and their individual roles during temperature challenges have either been described conflictingly or not at all.

Introducing high school biology students to biochemistry with a short, content-oriented module.

Many STEM disciplines are underrepresented to High School students. This is problematic as many students' decisions for college are shaped by their experiences and achievements in high school. Short content-oriented modules have been shown to encourage science identity and otherwise benefit the students' learning.

Oligogalactolipid production during cold challenge is conserved in early diverging lineages.

Severe cold, defined as a damaging cold beyond acclimation temperatures, has unique responses, but the signaling and evolution of these responses are not well understood. Production of oligogalactolipids, which is triggered by cytosolic acidification in Arabidopsis (Arabidopsis thaliana), contributes to survival in severe cold. Here, we investigated oligogalactolipid production in species from bryophytes to angiosperms.

Three Methods to Extract Membrane Glycerolipids: Comparing Sensitivity to Lipase Degradation and Yield.

Glycerolipids form the largest fraction of all membrane lipids and their composition changes quickly during plant development, the diurnal cycle, and in response to hormones and biotic or abiotic stress. A challenge to accurate glycerolipid measurement is that lipid-degrading enzymes tend to remain active during extraction, and special care must be taken to ensure their inactivation. Multiple extraction methods have arisen to cope with this challenge but only a few comparative studies are available in the literature.

Predicting transcriptional responses to cold stress across plant species.

Although genome-sequence assemblies are available for a growing number of plant species, gene-expression responses to stimuli have been cataloged for only a subset of these species. Many genes show altered transcription patterns in response to abiotic stresses. However, orthologous genes in related species often exhibit different responses to a given stress.

Teaching Metabolism in Upper-Division Undergraduate Biochemistry Courses using Online Computational Systems and Dynamical Models Improves Student Performance.

Understanding metabolic function requires knowledge of the dynamics, interdependence, and regulation of metabolic networks. However, multiple professional societies have recognized that most undergraduate biochemistry students acquire only a surface-level understanding of metabolism. We hypothesized that guiding students through interactive computer simulations of metabolic systems would increase their ability to recognize how individual interactions between components affect the behavior of a system under different conditions.

Introducing climate change into the biochemistry and molecular biology curriculum.

Our climate is changing due to anthropogenic emissions of greenhouse gases from the production and use of fossil fuels. Present atmospheric levels of CO were last seen 3 million years ago, when planetary temperature sustained high Arctic camels. As scientists and educators, we should feel a professional responsibility to discuss major scientific issues like climate change, and its profound consequences for humanity, with students who look up to us for knowledge and leadership, and who will be most affected in the future.

Interactive learning modules with 3D printed models improve student understanding of protein structure-function relationships.

Ensuring undergraduate students become proficient in relating protein structure to biological function has important implications. With current two-dimensional (2D) methods of teaching, students frequently develop misconceptions, including that proteins contain a lot of empty space, that bond angles for different amino acids can rotate equally, and that product inhibition is equivalent to allostery. To help students translate 2D images to 3D molecules and assign biochemical meaning to physical structures, we designed three 3D learning modules consisting of interactive activities with 3D printed models for amino acids, proteins, and allosteric regulation with coordinating pre- and post-assessments.

An Arabidopsis protoplast isolation method reduces cytosolic acidification and activation of the chloroplast stress sensor SENSITIVE TO FREEZING 2.

Chloroplasts adapt to freezing and other abiotic stresses in part by modifying their membranes. One key-remodeling enzyme is SENSITIVE TO FREEZING2 (SFR2). SFR2 is unusual because it does not respond to initial cold stress or cold acclimation, instead it responds during freezing conditions in Arabidopsis.

Parallels between natural selection in the cold-adapted crop-wild relative Tripsacum dactyloides and artificial selection in temperate adapted maize.

Artificial selection has produced varieties of domesticated maize that thrive in temperate climates around the world. However, the direct progenitor of maize, teosinte, is indigenous only to a relatively small range of tropical and subtropical latitudes and grows poorly or not at all outside of this region. Tripsacum, a sister genus to maize and teosinte, is naturally endemic to the majority of areas in the western hemisphere where maize is cultivated.

Student Understanding of DNA Structure-Function Relationships Improves from Using 3D Learning Modules with Dynamic 3D Printed Models.

Understanding the relationship between molecular structure and function represents an important goal of undergraduate life sciences. Although evidence suggests that handling physical models supports gains in student understanding of structure-function relationships, such models have not been widely implemented in biochemistry classrooms. Three-dimensional (3D) printing represents an emerging cost-effective means of producing molecular models to help students investigate structure-function concepts.

Low-temperature tolerance in land plants: Are transcript and membrane responses conserved?

Plants' tolerance of low temperatures is an economically and ecologically important limitation on geographic distributions and growing seasons. Tolerance for low temperatures varies significantly across different plant species, and different mechanisms likely act in different species. In order to survive low-temperature stress, plant membranes must maintain their fluidity in increasingly cold and oxidative cellular environments.

Lipid transport required to make lipids of photosynthetic membranes.

Photosynthetic membranes provide much of the usable energy for life on earth. To produce photosynthetic membrane lipids, multiple transport steps are required, including fatty acid export from the chloroplast stroma to the endoplasmic reticulum, and lipid transport from the endoplasmic reticulum to the chloroplast envelope membranes. Transport of hydrophobic molecules through aqueous space is energetically unfavorable and must be catalyzed by dedicated enzymes, frequently on specialized membrane structures.

Differentially Regulated Orthologs in Sorghum and the Subgenomes of Maize.

Identifying interspecies changes in gene regulation, one of the two primary sources of phenotypic variation, is challenging on a genome-wide scale. The use of paired time-course data on cold-responsive gene expression in maize () and sorghum () allowed us to identify differentially regulated orthologs. While the majority of cold-responsive transcriptional regulation of conserved gene pairs is species specific, the initial transcriptional responses to cold appear to be more conserved than later responses.

Correction: Genome, Functional Gene Annotation, and Nuclear Transformation of the Heterokont Oleaginous Alga Nannochloropsis oceanica CCMP1779.

[This corrects the article DOI: 10.1371/journal.pgen.

Polyglycine Acts as a Rejection Signal for Protein Transport at the Chloroplast Envelope.

PolyGly is present in many proteins in various organisms. One example is found in a transmembrane β-barrel protein, translocon at the outer-envelope-membrane of chloroplasts 75 (Toc75). Toc75 requires its N-terminal extension (t75) for proper localization.