The prominent multiplication of Japanese soil-borne wheat mosaic virus co-infected with barley yellow mosaic virus in barley.

Various members of the viral genera Furovirus and Bymovirus are damaging pathogens of a range of crop species. Infection of the soil-borne plasmodiophorid Polymyxa graminis transmits both Japanese soil-borne wheat mosaic virus (JSBWMV) and the barley yellow mosaic virus (BaYMV) to barley, but their interaction during an episode of their co-infection has not been characterized to date. Here, we present an analysis of the titer of JSBWMV and BaYMV in plants of winter barley growing over a five-month period from late fall until mid-spring.

Identification of Isolates Breaking Resistance in Japan.

In early spring 2018, significant mosaic disease symptoms were observed for the first time on barley leaves ( L., cv. New Sachiho Golden) in Takanezawa, Tochigi Prefecture, Japan.

Accumulation of mutations in the homoeologs causes suppression of anther extrusion with altered spike and culm development in hexaploid wheat.

Unlabelled: Cleistogamy or closed flowering is a widely used trait in barley () breeding because it reduces the risk of fungal infection in florets at anthesis. Cleistogamy in barley is caused by a point mutation within the microRNA172 (miR172) target site of the gene, which encodes the Apetala2 (AP2) transcription factor. Because cleistogamy is not apparent in cultivars of hexaploid wheat (), a strategy to develop cleistogamous wheat was proposed by inducing point mutations in all three homoeologs, which are the wheat orthologs of barley .

HOMEOBOX2, the paralog of SIX-ROWED SPIKE1/HOMEOBOX1, is dispensable for barley spikelet development.

The HD-ZIP class I transcription factor Homeobox 1 (HvHOX1), also known as Vulgare Row-type Spike 1 (VRS1) or Six-rowed Spike 1, regulates lateral spikelet fertility in barley (Hordeum vulgare L.). It was shown that HvHOX1 has a high expression only in lateral spikelets, while its paralog HvHOX2 was found to be expressed in different plant organs.

Most Tibetan weedy barleys originated via recombination between Btr1 and Btr2 in domesticated barley.

Tibetan weedy barleys reside at the edges of qingke (hulless barley) fields in Tibet (Xizang). The spikes of these weedy barleys contain or lack a brittle rachis, with either two- or six-rowed spikes and either hulled or hulless grains at maturity. Although the brittle rachis trait of Tibetan weedy barleys is similar to that of wild barley (Hordeum vulgare ssp.

Series of Resistance Genes in Barley () that Control Barley Yellow Mosaic Virus Multiplication and the Root-to-Leaf Systemic Movement.

The infection of young winter barley (e L.) root system in winter by barley yellow mosaic virus (BaYMV) can lead to high yield losses. Resistance breeding is critical for managing this virus, but there are only a few reports on resistance genes that describe how the genes control BaYMV propagation and the systemic movement from the roots to the leaves.

Mutations within the miR172 target site of wheat homoeologs regulate lodicule size and rachis internode length.

Closed fertilization in flowers, or cleistogamy, reduces the risk of fungal infection in Triticeae crops. In barley (), cleistogamy is determined by a single recessive gene, , which results from a single nucleotide polymorphism within the microRNA172 target site of the () transcription factor gene. The recessive allele negatively regulates the development of lodicules, keeping florets closed at anthesis.

Organ-enriched gene expression during floral morphogenesis in wild barley.

Floral morphology varies considerably between dicots and monocots. The ABCDE model explaining how floral organ development is controlled was formulated using core eudicots and applied to grass crops. Barley (Hordeum.

Genetic resistance in barley against functions in the roots.

Infection by the (JSBWMV) can lead to substantial losses in the grain yield of barley and wheat crops. While genetically based resistance to this virus has been documented, its mechanistic basis remains obscure. In this study, the deployment of a quantitative PCR assay showed that the resistance acts directly against the virus rather than by inhibiting the colonization of the roots by the virus' fungal vector .

Wheat originated from and confers resistance to soil-borne infection to the roots.

(WYMV) is a pathogen transmitted into its host's roots by the soil-borne vector . and genes protect the host from the significant yield losses caused by the virus, but the mechanistic basis of these resistance genes remains poorly understood. Here, it has been shown that and act within the root either by hindering the initial movement of WYMV from the vector into the root and/or by suppressing viral multiplication.

Integrated transcriptome and metabolome analysis reveals that flavonoids function in wheat resistance to powdery mildew.

Powdery mildew is a fungal disease devastating to wheat, causing significant quality and yield loss. Flavonoids are important secondary plant metabolites that confer resistance to biotic and abiotic stress. However, whether they play a role in powdery mildew resistance in wheat has yet to be explored.

Genome-Wide Analysis of Gene Family Reveals Potential Role in Regulation of Spike Development in Barley.

Sucrose nonfermenting 2 (Snf2) family proteins, as the catalytic core of ATP-dependent chromatin remodeling complexes, play important roles in nuclear processes as diverse as DNA replication, transcriptional regulation, and DNA repair and recombination. The gene family has been characterized in several plant species; some of its members regulate flower development in Arabidopsis. However, little is known about the members of the family in barley ().

Wheat Elongator Subunit 4 Negatively Regulates Freezing Tolerance by Regulating Ethylene Accumulation.

Freezing stress is a major factor limiting production and geographical distribution of temperate crops. Elongator is a six subunit complex with histone acetyl-transferase activity and is involved in plant development and defense responses in . However, it is unknown whether and how an elongator responds to freezing stress in plants.

Grain Disarticulation in Wild Wheat and Barley.

Our industrial-scale crop monocultures, which are necessary to provide grain for large-scale food and feed production, are highly vulnerable to biotic and abiotic stresses. Crop wild relatives have adapted to harsh environmental conditions over millennia; thus, they are an important source of genetic variation and crop diversification. Despite several examples where significant yield increases have been achieved through the introgression of genomic regions from wild relatives, more detailed understanding of the differences between wild and cultivated species for favorable and unfavorable traits is still required to harness these valuable resources.

Precise Genome Editing in miRNA Target Site via Gene Targeting and Subsequent Single-Strand-Annealing-Mediated Excision of the Marker Gene in Plants.

Gene targeting (GT) enables precise genome modification-e.g., the introduction of base substitutions-using donor DNA as a template.

A novel mutant allele at the Cleistogamy 1 locus in barley.

A chasmogamous mutant was induced by exposing a cleistogamous cultivar to sodium azide. The altered cly1 sequence in the mutant was not in the miR172 binding site, as is the case in other known cleistogamous alleles, but rather in a region encoding one of the gene product's two AP2 domains. The genetic basis of cleistogamy (in which pollination occurs before the flower opens) in barley is centered on the Cleistogamy 1 locus (cly1).

The Independent Domestication of Timopheev's Wheat: Insights from Haplotype Analysis of the () Gene.

and are two tetraploid wheat species sharing as a common ancestor, and domesticated accessions from both of these allopolyploids exhibit nonbrittle rachis (i.e., nonshattering spikes).

A genetic analysis of the resistance in barley to .

(SBWMV), a ubiquitous pathogen commonly encountered in temperate regions of the Northern hemisphere, can damage a number of economically important cereal crops, notably wheat and barley. Given that the plasmodiophorid cercozoan , which acts as the vector of SBWMV, can survive in the soil for many decades, the only feasible control measure is the deployment of resistant cultivars. Here, a quantitative trait locus (QTL) approach was taken to characterize the genetic basis of the SBWMV resistance exhibited by the barley cultivar Haruna Nijo.

The Ectopic Expression of in Switches the Disarticulation Layer From Above to Below the Rachis Node.

Seed dispersal among wild species belonging to the tribe Triticeae is typically achieved by the formation of a brittle rachis. The trait relies on the development of a disarticulation layer, most frequently above the rachis node (resulting in wedge type dispersal units), but in some species below the rachis node (resulting in barrel type dispersal units). The genes responsible for the former type are the complementary pair and , while the genetic basis of the latter type has yet to be determined.

The Brittle Rachis Trait in Species Belonging to the Triticeae and Its Controlling Genes and .

In many non-cultivated angiosperm species, seed dispersal is facilitated by the shattering of the seed head at maturity; in the Triticeae tribe, to which several of the world's most important cereals belong, shattering takes the form of a disarticulation of the rachis. The products of the genes and are both required for disarticulation to occur above the rachis nodes within the genera (barley) and (wheat). Here, it has been shown that both and are specific to the Triticeae tribe, although likely paralogs ( and ) are carried by the family Poaceae including Triticeae (the donor of the bread wheat D genome) lacks a copy of and disarticulation in this species occurs below, rather than above the rachis node; thus, the product of appears to be required for disarticulation to occur above the rachis node.

The unique disarticulation layer formed in the rachis of Aegilops longissima probably results from the spatial co-expression of Btr1 and Btr2.

Background And Aims: The brittle rachis trait is a feature of many wild grasses, particularly within the tribe Triticeae. Wild Hordeum and Triticum species form a disarticulation layer above the rachis node, resulting in the production of wedge-type dispersal units. In Aegilops longissima, only one or two of the nodes in the central portion of its rachis are brittle.

Wheat domestication in light of haplotype analyses of the Brittle rachis 1 genes (BTR1-A and BTR1-B).

Wheat domestication was a milestone in the rise of agrarian societies in the Fertile Crescent. As opposed to the freely dispersing seeds of its tetraploid progenitor wild emmer, the hallmark trait of domesticated wheat is intact, harvestable spikes. During domestication, wheat acquired recessive loss-of-function mutations in the Brittle Rachis 1 genes, both in the A genome (BTR1-A) and B genome (BTR1-B).