How FocA facilitates fermentation and respiration of formate by .

Formic acid is an important source of reductant and energy for many microorganisms. Formate is also produced as a fermentation product, e.g.

Dormancy: Metabolite pools prime the cyanobacterial dormancy-resuscitation switch.

Non-N-fixing cyanobacteria enter a state of dormancy when fixed nitrogen becomes limiting. Resuscitation from this state involves a complex program of events. A new study reveals how the dormancy-resuscitation switch is governed by metabolite-level control of glucose-6-phosphate dehydrogenase activity.

Maladaptation in cereal crop landraces following a soot-producing climate catastrophe.

Aerosol-producing global catastrophes such as nuclear war, super-volcano eruption, or asteroid strike, although rare, pose a serious threat to human survival. Light-absorbing aerosols would sharply reduce temperature and solar radiation reaching the earth's surface, decreasing crop productivity including for locally adapted traditional crop varieties, i.e.

Teosinte populations exhibit weak local adaptation to their rhizosphere biota despite strong effects of biota source on teosinte fitness and traits.

While biotic interactions often impose selection, species and populations vary in whether they are locally adapted to biotic interactions. Evolutionary theory predicts that environmental conditions drive this variable local adaptation by altering the fitness impacts of species interactions. To investigate the influence of an environmental gradient on adaptation between a plant and its associated rhizosphere biota, we cross-combined teosinte (Zea mays ssp.

The ancestral environment of teosinte populations shapes their root microbiome.

Background: The composition of the root microbiome affects the host's growth, with variation in the host genome associated with microbiome variation. However, it is not known whether this intra-specific variation of root microbiomes is a consequence of plants performing targeted manipulations of them to adapt to their local environment or varying passively with other traits. To explore the relationship between the genome, environment and microbiome, we sampled seeds from teosinte populations across its native range in Mexico.

Maize zinc uptake is influenced by arbuscular mycorrhizal symbiosis under various soil phosphorus availabilities.

The antagonistic interplay between phosphorus (P) and zinc (Zn) in plants is well established. However, the molecular mechanisms mediating those interactions as influenced by arbuscular mycorrhizal (AM) symbiosis remain unclear. We investigated Zn concentrations, root AM symbiosis, and transcriptome profiles of maize roots grown under field conditions upon different P levels.

The formate-hydrogen axis and its impact on the physiology of enterobacterial fermentation.

Formic acid (HCOOH) and dihydrogen (H) are characteristic products of enterobacterial mixed-acid fermentation, with H generation increasing in conjunction with a decrease in extracellular pH. Formate and acetyl-CoA are generated by radical-based and coenzyme A-dependent cleavage of pyruvate catalysed by pyruvate formate-lyase (PflB). Formate is also the source of H, which is generated along with carbon dioxide through the action of the membrane-associated, cytoplasmically-oriented formate hydrogenlyase (FHL-1) complex.

Seedling root system adaptation to water availability during maize domestication and global expansion.

The maize root system has been reshaped by indirect selection during global adaptation to new agricultural environments. In this study, we characterized the root systems of more than 9,000 global maize accessions and its wild relatives, defining the geographical signature and genomic basis of variation in seminal root number. We demonstrate that seminal root number has increased during maize domestication followed by a decrease in response to limited water availability in locally adapted varieties.

Heritable microbiome variation is correlated with source environment in locally adapted maize varieties.

Beneficial interactions with microorganisms are pivotal for crop performance and resilience. However, it remains unclear how heritable the microbiome is with respect to the host plant genotype and to what extent host genetic mechanisms can modulate plant-microbiota interactions in the face of environmental stresses. Here we surveyed 3,168 root and rhizosphere microbiome samples from 129 accessions of locally adapted Zea, sourced from diverse habitats and grown under control and different stress conditions.

Evidence that variation in root anatomy contributes to local adaptation in Mexican native maize.

Mexican native maize ( ssp. ) is adapted to a wide range of climatic and edaphic conditions. Here, we focus specifically on the potential role of root anatomical variation in this adaptation.

Evidence the Isc iron-sulfur cluster biogenesis machinery is the source of iron for [NiFe]-cofactor biosynthesis in Escherichia coli.

[NiFe]-hydrogenases have a bimetallic NiFe(CN)CO cofactor in their large, catalytic subunit. The 136 Da Fe(CN)CO group of this cofactor is preassembled on a distinct HypC-HypD scaffold complex, but the intracellular source of the iron ion is unresolved. Native mass spectrometric analysis of HypCD complexes defined the [4Fe-4S] cluster associated with HypD and identified + 26 to 28 Da and + 136 Da modifications specifically associated with HypC.

Evidence for bidirectional formic acid translocation in vivo via the Escherichia coli formate channel FocA.

Pentameric FocA permeates either formate or formic acid bidirectionally across the cytoplasmic membrane of anaerobically growing Escherichia coli. Each protomer of FocA has its own hydrophobic pore, but it is unclear whether formate or neutral formic acid is translocated in vivo. Here, we measured total and dicyclohexylcarbodiimide (DCCD)-inhibited proton flux out of resting, fermentatively grown, stationary-phase E.

Mycorrhizal status and host genotype interact to shape plant nutrition in field grown maize (Zea mays ssp. mays).

Arbuscular mycorrhizal fungi (AMF) establish symbioses with the major cereal crops, providing plants with increased access to nutrients while enhancing their tolerance to toxic heavy metals. However, not all plant varieties benefit equally from this association. In this study, we used quantitative trait loci (QTL) mapping to evaluate the combined effect of host genotypic variation (G) and AMF across 141 genotypes on the concentration of 20 mineral elements in the leaves and grain of field grown maize (Zea mays spp.

Differences in mucilage properties and stomatal sensitivity of locally adapted in relation with precipitation seasonality and vapour pressure deficit regime of their native environment.

With ongoing climate change and the increase in extreme weather events, especially droughts, the challenge of maintaining food security is becoming ever greater. Locally adapted landraces of crops represent a valuable source of adaptation to stressful environments. In the light of future droughts-both by altered soil water supply and increasing atmospheric water demand (vapor pressure deficit [VPD])-plants need to improve their water efficiency.

Genetic analysis and QTL mapping of domestication-related traits in chili pepper ( L).

Chili pepper ( L.) is one of the oldest and most phenotypically diverse pre-Columbian crops of the Americas. Despite the abundance of genetic resources, the use of wild germplasm and landraces in chili pepper breeding is limited.

Landscape transcriptomics as a tool for addressing global change effects across diverse species.

Landscape transcriptomics is an emerging field studying how genome-wide expression patterns reflect dynamic landscape-scale environmental drivers, including habitat, weather, climate, and contaminants, and the subsequent effects on organismal function. This field is benefitting from advancing and increasingly accessible molecular technologies, which in turn are allowing the necessary characterization of transcriptomes from wild individuals distributed across natural landscapes. This research is especially important given the rapid pace of anthropogenic environmental change and potential impacts that span levels of biological organization.

Perspective elucidating the physiology of a microbial cell: Neidhardt's Holy Grail.

A living microbial cell represents a system of high complexity, integration, and extreme order. All processes within that cell interconvert free energy through a multitude of interconnected metabolic reactions that help to maintain the cell in a state of low entropy, which is a characteristic of all living systems. The study of macromolecular interactions outside this cellular environment yields valuable information about the molecular function of macromolecules but represents a system in comparative disorder.

A redox-active HybG-HypD scaffold complex is required for optimal ATPase activity during [NiFe]-hydrogenase maturation in Escherichia coli.

Four Hyp proteins build a scaffold complex upon which the Fe(CN) CO group of the [NiFe]-cofactor of hydrogenases (Hyd) is made. Two of these Hyp proteins, the redox-active, [4Fe-4S]-containing HypD protein and the HypC chaperone, form the basis of this scaffold complex. Two different scaffold complexes exist in Escherichia coli, HypCD, and the paralogous HybG-HypD complex, both of which exhibit ATPase activity.

Genetic mapping of maize metabolites using high-throughput mass profiling.

Plant metabolites are the basis of human nutrition and have biological relevance in ecology. Farmers selected plants with favorable characteristics since prehistoric times and improved the cultivars, but without knowledge of underlying mechanisms. Understanding the genetic basis of metabolite production can facilitate the successful breeding of plants with augmented nutritional value.

Allele-specific Expression Reveals Multiple Paths to Highland Adaptation in Maize.

Maize is a staple food of smallholder farmers living in highland regions up to 4,000 m above sea level worldwide. Mexican and South American highlands are two major highland maize growing regions, and population genetic data suggest the maize's adaptation to these regions occurred largely independently, providing a case study for convergent evolution. To better understand the mechanistic basis of highland adaptation, we crossed maize landraces from 108 highland and lowland sites of Mexico and South America with the inbred line B73 to produce F1 hybrids and grew them in both highland and lowland sites in Mexico.

FocA and its central role in fine-tuning pH homeostasis of enterobacterial formate metabolism.

During enterobacterial mixed-acid fermentation, formate is generated from pyruvate by the glycyl-radical enzyme pyruvate formate-lyase (PflB). In , especially at low pH, formate is then disproportionated to CO and H by the cytoplasmically oriented, membrane-associated formate hydrogenlyase (FHL) complex. If electron acceptors are available, however, formate is oxidized by periplasmically oriented, respiratory formate dehydrogenases.

Distinguishing functional from structural roles of conserved pore residues during formate translocation by the FocA anion channel.

The formate-specific anion channel FocA of Escherichia coli belongs to the superfamily of homopentameric formate-nitrite transporters (FNT). Minimally nine amino acid residues are conserved in the formate translocation pore of each protomer of the pentamer, including a histidine (H209) and a threonine (T91), both of which are crucial for bidirectional formate translocation through the pore. Information regarding in vivo functional or structural roles for the other seven conserved residues is limited, or nonexistent.

The allele of conditions misregulation of the phosphorus starvation response in maize ( ssp. L.).

Plant PHO1 proteins play a central role in the translocation and sensing of inorganic phosphate. The maize ( ssp. ) genome encodes two co-orthologs of the gene, designated and .

An adaptive teosinte introgression modulates phosphatidylcholine levels and is associated with maize flowering time.

Native Americans domesticated maize ( ssp. ) from lowland teosinte ( ssp. in the warm Mexican southwest and brought it to the highlands of Mexico and South America where it was exposed to lower temperatures that imposed strong selection on flowering time.