Understanding the genetic basis of heat stress tolerance in wheat (Triticum aestivum L.) through genome-wide association studies.

Heat stress can reduce the production potential of wheat (Triticum aestivum L.) by affecting the various developmental stages of wheat including the seedling stage. Understanding the genetic basis of heat stress tolerance can help in breeding resilient wheat cultivars with improved productivity.

Identification and mapping of quantitative trait loci for Fusarium head blight resistance in a synthetic hexaploid × hard red spring wheat population.

Fusarium head blight (FHB), caused by Fusarium graminearum Schwabe, is one of the most devastating diseases in wheat (Triticum aestivum L.). The synthetic hexaploid wheat line Largo was developed from a cross between the durum wheat [T.

Development of diagnostic markers for the disease susceptibility gene Tsn1 in wheat reveals novel resistance alleles and a new locus required for ToxA sensitivity.

The wheat gene Tsn1 confers susceptibility to tan spot, septoria nodorum blotch, and spot blotch. The markers developed here may be immediately deployed in breeding programs to eliminate Tsn1. The wheat Tsn1 gene recognizes the necrotrophic effector ToxA, which is produced by three different necrotrophic fungal pathogens.

Identification of a novel genetic locus conferring virulence in the wheat tan spot pathogen Pyrenophora tritici-repentis.

The ascomycete Pyrenophora tritici-repentis (Ptr) is the causal agent of tan spot, a common and economically important wheat disease worldwide. Three necrotrophic effectors (NEs), known as Ptr ToxA, Ptr ToxB, and Ptr ToxC, have been identified from the fungal pathogen as major virulence factors. The race 2 isolate 86-124 which produces Ptr ToxA is capable of causing disease on wheat lines that is insensitive to Ptr ToxA, suggesting the use of additional NEs during the infection.

f. , Causal Agent of Spot Form Net Blotch of Barley, Is an Emerging Pathogen of Durum Wheat.

Emergent plant pathogens threaten global food security, as they evolve to infect new hosts and spread to new geographic regions. f. is a foliar pathogen of barley that is present worldwide and can cause significant yield losses.

Protein Kinase-Major Sperm Protein (PK-MSP) Genes Mediate Recognition of the Fungal Necrotrophic Effector SnTox3 to Cause Septoria nodorum Blotch in Wheat.

The wheat- pathosystem has emerged as a model system for plant-necrotrophic fungal pathogen interactions. In this system, fungal necrotrophic effectors are recognized by specific host genes in an inverse gene-for-gene manner to induce programmed cell death and other host responses, which leads to disease. We previously cloned a wheat gene () encoding protein kinase and major sperm protein domains that recognizes the necrotrophic effector SnTox3.

Genetic mapping of QTLs for resistance to bacterial leaf streak in hexaploid wheat.

Robust QTLs conferring resistance to bacterial leaf streak in wheat were mapped on chromosomes 3B and 5A from the variety Boost and on chromosome 7D from the synthetic wheat line W-7984. Bacterial leaf streak (BLS), caused by Xanthomonas translucens pv. undulosa poses a significant threat to global wheat production.

Evaluation of Durum and Hard Red Spring Wheat Panels for Sensitivity to Necrotrophic Effectors Produced by .

Septoria nodorum blotch (SNB) is an important disease of both durum and hard red spring wheat (HRSW) worldwide. The disease is caused by the necrotrophic fungal pathogen when compatible gene-for-gene interactions occur between pathogen-produced necrotrophic effectors (NEs) and corresponding host sensitivity genes. To date, nine sensitivity gene-NE interactions have been identified, but there is little information available regarding their overall frequency in durum and HRSW.

Association mapping of tan spot and septoria nodorum blotch resistance in cultivated emmer wheat.

A total of 65 SNPs associated with resistance to tan spot and septoria nodorum blotch were identified in a panel of 180 cultivated emmer accessions through association mapping Tan spot and septoria nodorum blotch (SNB) are foliar diseases caused by the respective fungal pathogens Pyrenophora tritici-repentis and Parastagonospora nodorum that affect global wheat production. To find new sources of resistance, we evaluated a panel of 180 cultivated emmer wheat (Triticum turgidum ssp. dicoccum) accessions for reactions to four P.

Evolution, diversity, and function of the disease susceptibility gene Snn1 in wheat.

Septoria nodorum blotch (SNB), caused by Parastagonospora nodorum, is a disease of durum and common wheat initiated by the recognition of pathogen-produced necrotrophic effectors (NEs) by specific wheat genes. The wheat gene Snn1 was previously cloned, and it encodes a wall-associated kinase that directly interacts with the NE SnTox1 leading to programmed cell death and ultimately the development of SNB. Here, sequence analysis of Snn1 from 114 accessions including diploid, tetraploid, and hexaploid wheat species revealed that some wheat lines possess two copies of Snn1 (designated Snn1-B1 and Snn1-B2) approximately 120 kb apart.

Identification of robust yield quantitative trait loci derived from cultivated emmer for durum wheat improvement.

Durum wheat (Triticum turgidum ssp. durum L.) is an important world food crop used to make pasta products.

Sequencing 4.3 million mutations in wheat promoters to understand and modify gene expression.

Wheat is an important contributor to global food security, and further improvements are required to feed a growing human population. Functional genetics and genomics tools can help us to understand the function of different genes and to engineer beneficial changes. In this study, we used a promoter capture assay to sequence 2-kb regions upstream of all high-confidence annotated genes from 1,513 mutagenized plants from the tetraploid wheat variety Kronos.

The Necrotrophic Pathogen Is a Master Manipulator of Wheat Defense.

is a necrotrophic pathogen of wheat that is particularly destructive in major wheat-growing regions of the United States, northern Europe, Australia, and South America. secretes necrotrophic effectors that target wheat susceptibility genes to induce programmed cell death (PCD), resulting in increased colonization of host tissue and, ultimately, sporulation to complete its pathogenic life cycle. Intensive research over the last two decades has led to the functional characterization of five proteinaceous necrotrophic effectors, , , , , and , and three wheat susceptibility genes, , , and Functional characterization has revealed that these effectors, in addition to inducing PCD, have additional roles in pathogenesis, including chitin binding that results in protection from wheat chitinases, blocking defense response signaling, and facilitating plant colonization.

Linkage drag analysis in three Aegilops speltoides introgressions carrying Sr47 in modern durum and hard red spring wheat germplasm.

Yield and quality tests of wheat lines derived from RWG35 show they carry little, or no linkage drag and are the preferred source of Sr47 for stem rust resistance. Three durum wheat (Triticum turgidum L. subsp.

Genome-wide association mapping of resistance to the foliar diseases septoria nodorum blotch and tan spot in a global winter wheat collection.

Unlabelled: Septoria nodorum blotch (SNB) and tan spot, caused by the necrotrophic fungal pathogens and , respectively, often occur together as a leaf spotting disease complex on wheat ( L.). Both pathogens produce necrotrophic effectors (NEs) that contribute to the development of disease.

Association Mapping of Resistance to Tan Spot in the Global Durum Panel.

Tan spot, caused by the necrotrophic fungal pathogen (Ptr), is an important disease of durum and common wheat worldwide. Compared with common wheat, less is known about the genetics and molecular basis of tan spot resistance in durum wheat. We evaluated 510 durum lines from the Global Durum Wheat Panel (GDP) for sensitivity to the necrotrophic effectors (NEs) Ptr ToxA and Ptr ToxB and for reaction to Ptr isolates representing races 1 to 5.

Prevalence and Importance of the Necrotrophic Effector Gene in Populations Collected from Spring Wheat and Barley.

is a necrotrophic fungal pathogen that causes foliar and root diseases on wheat and barley. These diseases are common in all wheat- and barley-growing regions, with more severe outbreaks occurring under warm and humid conditions. can also infect a wide range of grass species in the family Poaceae and secrete , an important necrotrophic effector also identified other wheat leaf spotting pathogens.

Optimization of highly efficient exogenous-DNA-free Cas9-ribonucleoprotein mediated gene editing in disease susceptibility loci in wheat ().

The advancement of precision engineering for crop trait improvement is important in the face of rapid population growth, climate change, and disease. To this end, targeted double-stranded break technology using RNA-guided Cas9 has been adopted widely for genome editing in plants. or particle bombardment-based delivery of plasmids encoding Cas9 and guide RNA (gRNA) is common, but requires optimization of expression and often results in random integration of plasmid DNA into the plant genome.

Identification of stable QTL controlling multiple yield components in a durum × cultivated emmer wheat population under field and greenhouse conditions.

Crop yield gains are needed to keep pace with a growing global population and decreasing resources to produce food. Cultivated emmer wheat is a progenitor of durum wheat and a useful source of genetic variation for trait improvement in durum. Here, we evaluated a recombinant inbred line population derived from a cross between the North Dakota durum wheat variety Divide and the cultivated emmer wheat accession PI 272527 consisting of 219 lines.

Genomic Analysis and Delineation of the Tan Spot Susceptibility Locus in Wheat.

The necrotrophic fungal pathogen () causes the foliar disease tan spot in both bread wheat and durum wheat. Wheat lines carrying the tan spot susceptibility gene are sensitive to the -produced necrotrophic effector (NE) Ptr ToxC. A compatible interaction results in leaf chlorosis, reducing yield by decreasing the photosynthetic area of leaves.

A Conserved Hypothetical Gene Is Required but Not Sufficient for Ptr ToxC Production in .

The fungus causes tan spot, an important foliar disease of wheat worldwide. The fungal pathogen produces three necrotrophic effectors, namely Ptr ToxA, Ptr ToxB, and Ptr ToxC to induce necrosis or chlorosis in wheat. Both Ptr ToxA and Ptr ToxB are proteins, and their encoding genes have been cloned.

Genetics of resistance to septoria nodorum blotch in wheat.

Septoria nodorum blotch (SNB) is a foliar disease of wheat caused by the necrotrophic fungal pathogen Parastagonospora nodorum. Research over the last two decades has shown that the wheat-P. nodorum pathosystem mostly follows an inverse gene-for-gene model.

Characterization of synthetic wheat line Largo for resistance to stem rust.

Resistance breeding is an effective approach against wheat stem rust caused by Puccinia graminis f. sp. tritici (Pgt).

The Parastagonospora nodorum necrotrophic effector SnTox5 targets the wheat gene Snn5 and facilitates entry into the leaf mesophyll.

Parastagonospora nodorum is an economically important necrotrophic fungal pathogen of wheat. Parastagonospora nodorum secretes necrotrophic effectors that target wheat susceptibility genes to induce programmed cell death (PCD). In this study, we cloned and functionally validated SnTox5 and characterized its role in pathogenesis.