Benthic remineralization under future Arctic conditions and evaluating the potential for changes in carbon sequestration in warming sediments.

Benthic (seafloor) remineralization of organic material determines the fate of carbon in the ocean and its sequestration. Bottom water temperature and labile carbon supply to the seafloor are expected to increase in a warming Arctic and correspondingly, benthic remineralization rates. We provide some of the first experimental data on the response of sediment oxygen demand (SOD), an established proxy for benthic remineralization, to increased temperature and/or food supply across a range of Arctic conditions and regimes.

Dietary plasticity in small Arctic copepods as revealed with prey metabarcoding.

Objectives: Small copepods (<2 mm) compose an important constituent of the Arctic marine food web, but their trophic interactions remain largely unexplored, partly due to methodological limitations.

Methods: We here characterize the prey of the abundant cyclopoid , harpacticoid and calanoid spp. from the Arctic Barents Sea and Nansen Basin during four seasons using brute force prey metabarcoding of the 18S rRNA gene.

High uptake of sympagic organic matter by benthos on an Arctic outflow shelf.

On Arctic shelves, benthic food-webs are tightly linked to overlying primary production. In the seasonal ice zone, sympagic (ice-associated) primary production can be a major source of carbon for the benthos on productive inflow shelves. However, the role of sympagic organic matter is less well-understood in food webs of heavily ice-covered, less- productive outflow shelves, such as the northeast Greenland shelf.

Draft genome sequences for four isolates of the hemp () fungal pathogen .

Four isolates of , collected from diseased hemp () plants over a period of 2 years and shown to be pathogenic on were examined in this study. Their genome sizes ranged between 42.8 and 44.

Seafloor warm water temperature anomalies impact benthic macrofauna communities of a high-Arctic cold-water fjord.

Amid the alarming atmospheric and oceanic warming rates taking place in the Arctic, western fjords around the Svalbard archipelago are experiencing an increased frequency of warm water intrusions in recent decades, causing ecological shifts in their ecosystems. However, hardly anything is known about their potential impacts on the until recently considered stable and colder northern fjords. We analyzed macrobenthic fauna from four locations in Rijpfjorden (a high-Arctic fjord in the north of Svalbard) along its axis, sampled intermittently in the years 2003, 2007, 2010, 2013 and 2017.

Reduced efficiency of pelagic-benthic coupling in the Arctic deep sea during lower ice cover.

Pelagic-benthic coupling describes the connection between surface-water production and seafloor habitats via energy, nutrient and mass exchange. Massive ice loss and warming in the poorly studied Arctic Chukchi Borderland are hypothesized to affect this coupling. The strength of pelagic-benthic coupling was compared between 2 years varying in climate settings, 2005 and 2016, based on δC and δN stable isotopes of food-web end-members and pelagic and deep-sea benthic consumers.

Isotopic turnover in polar cod (Boreogadus saida) muscle determined through a controlled feeding experiment.

Polar cod (Boreogadus saida) is an important trophic link within Arctic marine food webs and is likely to experience diet shifts in response to climate change. One important tool for assessing organism diet is bulk stable isotope analysis. However, key parameters necessary for interpreting the temporal context of stable isotope values are lacking, especially for Arctic species.

Asymmetrical lineage introgression and recombination in populations of Aspergillus flavus: Implications for biological control.

Aspergillus flavus is an agriculturally important fungus that causes ear rot of maize and produces aflatoxins, of which B1 is the most carcinogenic naturally-produced compound. In the US, the management of aflatoxins includes the deployment of biological control agents that comprise two nonaflatoxigenic A. flavus strains, either Afla-Guard (member of lineage IB) or AF36 (lineage IC).

Ablation of the miRNA cluster 24 in cartilage and osteoblasts impairs bone remodeling.

MicroRNAs (miRNAs) post-transcriptionally regulate cartilage and bone development and function, however, only few miRNAs have been described to play a role for cartilage to bone transition in vivo. Previously, we showed that cartilage-specific deletion of the Mirc24 cluster in newborn male mice leads to impaired growth plate cartilage development due to increased RAF/MEK/ERK signaling and affects the stability of the cartilage extracellular matrix on account of decreased SOX6 and SOX9 and increased MMP13 levels. Here, we studied how Mirc24 cluster inactivation in cartilage and osteoblasts leads to an increased bone density associated with defects in collagen remodeling in trabecular bone.

, sp. nov., is an emerging root-associated pathogen responsible for taproot decline of soybean in the southern United States.

Taproot decline (TRD) is a disease of soybean that has been reported recently from the southern United States (U.S.).

Arctic coastal benthos long-term responses to perturbations under climate warming.

Climate warming influences structure and function of Arctic benthic ecosystems. Assessing the response of these systems to perturbations requires long-term studies addressing key ecological processes related to recolonization and succession of species. Based on unique time-series (1980-2017), this study addresses successional patterns of hard-bottom benthos in two fjords in NW Svalbard after a pulse perturbation in 1980 and during a period of rapid climate warming.

Ablation of the miRNA Cluster 24 Has Profound Effects on Extracellular Matrix Protein Abundance in Cartilage.

MicroRNAs (miRNAs) regulate cartilage differentiation and contribute to the onset and progression of joint degeneration. These small RNA molecules may affect extracellular matrix organization (ECM) in cartilage, but for only a few miRNAs has this role been defined . Previously, we showed that cartilage-specific genetic ablation of the Mirc24 cluster in mice leads to impaired cartilage development due to increased RAF/MEK/ERK pathway activation.

101 genomes: A test case for predicting lifestyles and emergence of pathogens.

is the largest class of kingdom Fungi and comprises an incredible diversity of lifestyles, many of which have evolved multiple times. Plant pathogens represent a major ecological niche of the class and they are known to infect most major food crops and feedstocks for biomass and biofuel production. Studying the ecology and evolution of has significant implications for our fundamental understanding of fungal evolution, their adaptation to stress and host specificity, and practical implications with regard to the effects of climate change and on the food, feed, and livestock elements of the agro-economy.

Pelagic occurrences of the ice amphipod throughout the Arctic.

is a common, sea ice-associated amphipod found throughout the Arctic Ocean and has long been considered permanently associated with the sea ice habitat. However, pelagic occurrences of have also been reported. It was recently suggested that overwinters at depth within the Atlantic-water inflow near Svalbard, to avoid being exported out of the Arctic Ocean through the Fram Strait.

Variable genome evolution in fungi after transposon-mediated amplification of a housekeeping gene.

Background: Transposable elements (TEs) can be key drivers of evolution, but the mechanisms and scope of how they impact gene and genome function are largely unknown. Previous analyses revealed that TE-mediated gene amplifications can have variable effects on fungal genomes, from inactivation of function to production of multiple active copies. For example, a DNA methyltransferase gene in the wheat pathogen (synonym ) was amplified to tens of copies, all of which were inactivated by Repeat-Induced Point mutation (RIP) including the original, resulting in loss of cytosine methylation.

Effectiveness of a Seed Plate Assay for Evaluating Charcoal Rot Resistance in Soybean and the Relationship to Field Performance.

Charcoal rot of soybean, caused by , is a disease of economic significance in the United States. Although there are soybean cultivars with moderate resistance, identifying and quantifying resistance is challenging. Existing assays are time consuming, and results are often highly variable.

Respiratory chain inactivation links cartilage-mediated growth retardation to mitochondrial diseases.

In childhood, skeletal growth is driven by transient expansion of cartilage in the growth plate. The common belief is that energy production in this hypoxic tissue mainly relies on anaerobic glycolysis and not on mitochondrial respiratory chain (RC) activity. However, children with mitochondrial diseases causing RC dysfunction often present with short stature, which indicates that RC activity may be essential for cartilage-mediated skeletal growth.

Changes in the Fungal Microbiome of Maize During Hermetic Storage in the United States and Kenya.

Prior to harvest, maize kernels are invaded by a diverse population of fungal organisms that comprise the microbiome of the grain mass. Poor post-harvest practices and improper drying can lead to the growth of mycotoxigenic storage fungi and deterioration of grain quality. Hermetic storage bags are a low-cost technology for the preservation of grain during storage, which has seen significant adoption in many regions of Sub-Saharan Africa.

Depletion of Collagen IX Alpha1 Impairs Myeloid Cell Function.

The trabecular extracellular matrix (ECM) forms a three-dimensional scaffold to stabilize the bone marrow, provide substrates for cell-matrix interactions and retain, present or release signals to modulate hematopoietic stem and progenitor cell development. However, the impact of trabecular ECM components on hematopoiesis has been poorly studied. Using collagen IX alpha1 - deficient (Col9a1 ) mice, we revealed that a lack of collagen IX alpha1 results in a disorganized trabecular network enriched in fibronectin, and in a reduction in myeloid cells, which was accompanied by a decrease in colony-stimulating factor 1 receptor expression on monocytes from the bone marrow.

Genome Sequences of Three Races of Peronospora effusa: A Resource for Studying the Evolution of the Spinach Downy Mildew Pathogen.

Downy mildew disease, caused by the obligate oomycete pathogen Peronospora effusa, is the most important economic constraint for spinach production. Three races (races 12, 13, and 14) of P. effusa have been sequenced and assembled.

Sea ice meiofauna distribution on local to pan-Arctic scales.

Arctic sea ice provides microhabitats for biota that inhabit the liquid-filled network of brine channels and the ice-water interface. We used meta-analysis of 23 published and unpublished datasets comprising 721 ice cores to synthesize the variability in composition and abundance of sea ice meiofauna at spatial scales ranging from within a single ice core to pan-Arctic and seasonal scales. Two-thirds of meiofauna individuals occurred in the bottom 10 cm of the ice.

Draft genome sequence of sp., the causal agent of taproot decline of soybean in the southern United States.

The draft genome of sp. isolate MSU_SB201401, causal agent of taproot decline of soybean in the southern U.S.

IMA Genome-F 8: Draft genome of , , and .

The genomes of , , and are presented in this genome announcement. Three of these genomes are from plant pathogens and otherwise economically important fungal species. and are not known to cause significant disease but are closely related to species of economic importance.

The genome sequence of Bipolaris cookei reveals mechanisms of pathogenesis underlying target leaf spot of sorghum.

Bipolaris cookei (=Bipolaris sorghicola) causes target leaf spot, one of the most prevalent foliar diseases of sorghum. Little is known about the molecular basis of pathogenesis in B. cookei, in large part due to a paucity of resources for molecular genetics, such as a reference genome.