Elevated CO Can Worsen Fusarium Head Blight Disease Severity in Wheat but the QTL Provides Reliable Disease Resistance.

Fusarium head blight (FHB) is a destructive fungal disease of wheat that causes significant economic loss due to lower yields and the contamination of grain with fungal toxins (mycotoxins), particularly deoxynivalenol (DON). FHB disease spread and mycotoxin contamination has been shown to worsen at elevated CO, therefore, it is important to identify climate-resilient FHB resistance. This work evaluates whether wheat with the quantitative trait locus (QTL), the most widely deployed FHB resistance locus in wheat breeding programs, provides reliable disease resistance at elevated CO.

disease resistance QTL does not exacerbate wheat grain protein loss at elevated CO.

Fusarium head blight, a devastating cereal crop disease, can cause significant yield losses and contaminate grain with hazardous fungal toxins. Concerningly, recent evidence indicates that substantial grain protein content loss is likely to occur in wheat that is moderately resistant to head blight when it is grown at elevated CO. Although wheat breeders in North America utilize a number of resistance sources and genes to reduce pathogen damage, the gene is widely deployed.

Climate change may outpace current wheat breeding yield improvements in North America.

Variety adaptation to future climate for wheat is important but lacks comprehensive understanding. Here, we evaluate genetic advancement under current and future climate using a dataset of wheat breeding nurseries in North America during 1960-2018. Results show that yields declined by 3.

A Homolog of the Gene Is Involved in Nonhost Resistance to Wheat Stem Rust in .

Plants resist infection by pathogens using both preexisting barriers and inducible defense responses. Inducible responses are governed in a complex manner by various hormone signaling pathways. The relative contribution of hormone signaling pathways to nonhost resistance to pathogens is not well understood.

Heritable temporal gene expression patterns correlate with metabolomic seed content in developing hexaploid oat seed.

Oat ranks sixth in world cereal production and has a higher content of health-promoting compounds compared with other cereals. However, there is neither a robust oat reference genome nor transcriptome. Using deeply sequenced full-length mRNA libraries of oat cultivar Ogle-C, a de novo high-quality and comprehensive oat seed transcriptome was assembled.

Genetic Variation for Seed Metabolite Levels in .

Metabolite composition and concentrations in seed grains are important traits of cereals. To identify the variation in the seed metabolotypes of a model grass, namely , we applied a widely targeted metabolome analysis to forty inbred lines of and examined the accumulation patterns of 183 compounds in the seeds. By comparing the metabolotypes with the population structure of these lines, we found signature metabolites that represent different accumulation patterns for each of the three subpopulations.

Genomic Dissection of Nonhost Resistance to Wheat Stem Rust in Brachypodium distachyon.

The emergence of new races of Puccinia graminis f. sp. tritici, the causal pathogen of wheat stem rust, has spurred interest in developing durable resistance to this disease in wheat.

Quantitative Trait Loci Associated with Drought Tolerance in .

The temperate wild grass (Brachypodium) serves as model system for studying turf and forage grasses. Brachypodium collections show diverse responses to drought stress, but little is known about the genetic mechanisms of drought tolerance of this species. The objective of this study was to identify quantitative trait loci (QTLs) associated with drought tolerance traits in Brachypodium.

De Novo Transcriptome Assembly in Polyploid Species.

In the absence of a reference genome, the ultimate goal of a de novo transcriptome assembly is to accurately and comprehensively reconstruct the set of messenger RNA transcripts represented in the sample. Non-reference assembly of the transcriptome of polyploid species poses a particular challenge because of the presence of homeologs that are difficult to disentangle at the sequence level. This is especially true for hexaploid oats, which have three highly similar subgenomes, two of which are thought to be nearly identical.

Genetic Architecture of Flowering-Time Variation in Brachypodium distachyon.

The transition to reproductive development is a crucial step in the plant life cycle, and the timing of this transition is an important factor in crop yields. Here, we report new insights into the genetic control of natural variation in flowering time in Brachypodium distachyon, a nondomesticated pooid grass closely related to cereals such as wheat (Triticum spp.) and barley (Hordeum vulgare L.

Quantitative trait loci associated with natural diversity in water-use efficiency and response to soil drying in Brachypodium distachyon.

All plants must optimize their growth with finite resources. Water use efficiency (WUE) measures the relationship between biomass acquisition and transpired water. In the present study, we performed two experiments to understand the genetic basis of WUE and other parameters of plant-water interaction under control and water-limited conditions.

Cell Wall Composition and Biomass Recalcitrance Differences Within a Genotypically Diverse Set of Brachypodium distachyon Inbred Lines.

Brachypodium distachyon (Brachypodium) has emerged as a useful model system for studying traits unique to graminaceous species including bioenergy crop grasses owing to its amenability to laboratory experimentation and the availability of extensive genetic and germplasm resources. Considerable natural variation has been uncovered for a variety of traits including flowering time, vernalization responsiveness, and above-ground growth characteristics. However, cell wall composition differences remain underexplored.

Subgenome-specific assembly of vitamin E biosynthesis genes and expression patterns during seed development provide insight into the evolution of oat genome.

Vitamin E is essential for humans and thus must be a component of a healthy diet. Among the cereal grains, hexaploid oats (Avena sativa L.) have high vitamin E content.

A spontaneous segmental deletion from chromosome arm 3DL enhances Fusarium head blight resistance in wheat.

Much effort has been directed at identifying sources of resistance to Fusarium head blight (FHB) in wheat. We sought to identify molecular markers for what we hypothesized was a new major FHB resistance locus originating from the wheat cultivar 'Freedom' and introgressed into the susceptible wheat cultivar 'USU-Apogee'. An F2:3 mapping population from a cross between Apogee and A30, its BC4 near-isoline exhibiting improved FHB resistance, was evaluated for resistance.

Brachypodium distachyon-Cochliobolus sativus Pathosystem is a New Model for Studying Plant-Fungal Interactions in Cereal Crops.

Cochliobolus sativus (anamorph: Bipolaris sorokiniana) causes spot blotch, common root rot, and kernel blight or black point in barley and wheat. However, little is known about the molecular mechanisms underlying the pathogenicity of C. sativus or the molecular basis of resistance and susceptibility in the hosts.

Update on the genomics and basic biology of Brachypodium: International Brachypodium Initiative (IBI).

The scientific presentations at the First International Brachypodium Conference (abstracts available at http://www.brachy2013.unimore.

Genome diversity in Brachypodium distachyon: deep sequencing of highly diverse inbred lines.

Brachypodium distachyon is small annual grass that has been adopted as a model for the grasses. Its small genome, high-quality reference genome, large germplasm collection, and selfing nature make it an excellent subject for studies of natural variation. We sequenced six divergent lines to identify a comprehensive set of polymorphisms and analyze their distribution and concordance with gene expression.

Molecular and comparative mapping of genes governing spike compactness from wild emmer wheat.

The development and morphology of the wheat spike is important because the spike is where reproduction occurs and it holds the grains until harvest. Therefore, genes that influence spike morphology are of interest from both theoretical and practical stand points. When substituted for the native chromosome 2A in the tetraploid Langdon (LDN) durum wheat background, the Triticum turgidum ssp.

Parallel analysis of RNA ends enhances global investigation of microRNAs and target RNAs of Brachypodium distachyon.

Background: The wild grass Brachypodium distachyon has emerged as a model system for temperate grasses and biofuel plants. However, the global analysis of miRNAs, molecules known to be key for eukaryotic gene regulation, has been limited in B. distachyon to studies examining a few samples or that rely on computational predictions.

Analysis and annotation of the hexaploid oat seed transcriptome.

Background: Next generation sequencing provides new opportunities to explore transcriptomes. However, challenges remain for accurate differentiation of homoeoalleles and paralogs, particularly in polyploid organisms with no supporting genome sequence. In this study, RNA-Seq was employed to generate and characterize the first gene expression atlas for hexaploid oat.

Infection of Brachypodium distachyon by formae speciales of Puccinia graminis: early infection events and host-pathogen incompatibility.

Puccinia graminis causes stem rust, a serious disease of cereals and forage grasses. Important formae speciales of P. graminis and their typical hosts are P.

Fine mapping of the Bsr1 barley stripe mosaic virus resistance gene in the model grass Brachypodium distachyon.

The ND18 strain of Barley stripe mosaic virus (BSMV) infects several lines of Brachypodium distachyon, a recently developed model system for genomics research in cereals. Among the inbred lines tested, Bd3-1 is highly resistant at 20 to 25 °C, whereas Bd21 is susceptible and infection results in an intense mosaic phenotype accompanied by high levels of replicating virus. We generated an F(6:7) recombinant inbred line (RIL) population from a cross between Bd3-1 and Bd21 and used the RILs, and an F(2) population of a second Bd21 × Bd3-1 cross to evaluate the inheritance of resistance.

QTLs for resistance to the false brome rust Puccinia brachypodii in the model grass Brachypodium distachyon L.

The potential of the model grass Brachypodium distachyon L. (Brachypodium) for studying grass-pathogen interactions is still underexploited. We aimed to identify genomic regions in Brachypodium associated with quantitative resistance to the false brome rust fungus Puccinia brachypodii .

Grain dormancy and light quality effects on germination in the model grass Brachypodium distachyon.

• Lack of grain dormancy in cereal crops such as barley and wheat is a common problem affecting farming areas around the world, causing losses in yield and quality because of preharvest sprouting. Control of seed or grain dormancy has been investigated extensively using various approaches in different species, including Arabidopsis and cereals. However, the use of a monocot model plant such as Brachypodium distachyon presents opportunities for the discovery of new genes related to grain dormancy that are not present in modern commercial crops.