Identification of Barley yellow mosaic virus Isolates Breaking rym3 Resistance in Japan.

In early spring 2018, significant mosaic disease symptoms were observed for the first time on barley leaves (Hordeum vulgare L., cv. New Sachiho Golden) in Takanezawa, Tochigi Prefecture, Japan. This cultivar carries the resistance gene rym3 (rym; resistance to yellow mosaic). Through RNA-seq analysis, Barley yellow mosaic virus (BaYMV-Takanezawa) was identified in the roots of all five plants (T01-T05) in the field. Phylogenetic analysis of RNA1, encompassing known BaYMV pathotypes I through V, revealed that it shares the same origin as isolate pathotype IV (BaYMV-Ohtawara pathotype). However, RNA2 analysis of isolates revealed the simultaneous presence of two distinct BaYMV isolates, BaYMV-Takanezawa-T01 (DRR552862, closely related to pathotype IV) and BaYMV-Takanezawa-T02 (DRR552863, closely related to pathotype III). The amino acid sequences of the BaYMV-Takanezawa isolates displayed variations, particularly in the VPg and N-terminal region of CP, containing mutations not found in other domains of the virus genome. Changes in the CI (RNA1 amino acid residue 459) and CP (RNA1 amino acid residue 2138) proteins correlated with pathogenicity. These findings underscore the importance of monitoring and understanding the genetic diversity of BaYMV for effective disease management strategies in crop breeding.

Genetic resistance in barley against Japanese soil-borne wheat mosaic virus functions in the roots.

Infection by the Japanese soil-borne wheat mosaic virus (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 Polymyxa graminis. In the susceptible barley cultivar (cv.) Tochinoibuki, the JSBWMV titre was maintained at a high level in the roots during the period December-April, and the virus was translocated from the root to the leaf from January onwards. In contrast, in the roots of both cv. Sukai Golden and cv. Haruna Nijo, the titre was retained at a low level, and translocation of the virus to the shoot was strongly suppressed throughout the host's entire life cycle. The roots of wild barley (Hordeum vulgare ssp. spontaneum) accession H602 responded in the early stages of infection similarly to those of the resistant cultivated forms, but the host was unable to suppress the translocation of the virus to the shoot from March onwards. The virus titre in the root was presumed to have been restricted by the action of the gene product of Jmv1 (on chromosome 2H), while the stochastic nature of the infection was suppressed by the action of that of Jmv2 (on chromosome 3H), a gene harbored by cv. Sukai Golden but not by either cv. Haruna Nijo or accession H602.

Genomic traces of Japanese malting barley breeding in two modern high-quality cultivars, 'Sukai Golden' and 'Sachiho Golden'.

Two modern high-quality Japanese malting barley cultivars, 'Sukai Golden' and 'Sachiho Golden', were subjected to RNA-sequencing of transcripts extracted from 20-day-old immature seeds. Despite their close relation, 2,419 Sukai Golden-specific and 3,058 Sachiho Golden-specific SNPs were detected in comparison to the genome sequences of two reference cultivars: 'Morex' and 'Haruna Nijo'. Two single nucleotide polymorphism (SNP) clusters respectively showing the incorporation of (1) the barley yellow mosaic virus (BaYMV) resistance gene rym5 from six-row non-malting Chinese landrace Mokusekko 3 on the long arm of 3H, and (2) the anthocyanin-less ant2 gene from a two-row Dutch cultivar on the long arm of 2H were detected specifically in 'Sukai Golden'. Using 221 recombinant inbred lines of a cross between 'Ishukushirazu' and 'Nishinochikara', another BaYMV resistance rym3 gene derived from six-row non-malting Japanese cultivar 'Haganemugi' was mapped to a 0.4-cM interval on the proximal region of 5H. Haplotype analysis of progenitor accessions of the two modern malting cultivars revealed that rym3 of 'Haganemugi' was independently introduced into 'Sukai Golden' and 'Sachiho Golden'. Residual chromosome 5H segments of 'Haganemugi' surrounding rym3 were larger in 'Sukai Golden'. Available results suggest possibilities for malting quality improvement by minimizing residual segments surrounding rym3.

Two dominant genes in barley (Hordeum vulgare L.) complementarily encode perfect resistance to Japanese soil-borne wheat mosaic virus.

Japanese soil-borne wheat mosaic virus (Furovirus) is a damaging pathogen of wheat and barley. This virus can survive in the soil for several decades, so the deployment of resistant cultivars represents the only practical control measure. Here, a genetic analysis has identified two regions of the barley genome-one on chromosome 2H and the other on chromosome 3H-as harboring gene(s) encoding resistance to this virus. The joint presence of both loci, termed Jmv1 and Jmv2, made the plants essentially immune, with resistance being dominant over susceptibility at each locus. Phylogenetic analysis showed that the virus is not closely related to the type Furovirus species Soil-borne wheat mosaic virus. There was a difference between the RNA1- and RNA2-based phylogenies of the virus species in Furovirus implying the independent segregation of the virus subgenomes.

Utility of a GFP-expressing Barley yellow mosaic virus for analyzing disease resistance genes.

The soil-borne plasmodiophorid Polymyxa graminis is a vector for Barley yellow mosaic virus (BaYMV), which can severely damage barley plants. Although 22 disease resistance genes have been identified, only a few have been used for breeding virus-resistant cultivars. Recently, BaYMV strains capable of overcoming the effects of some of these genes have been detected. In this study, green fluorescent protein (GFP)-expressing BaYMV was constructed and used to examine viral dynamics in inoculated barley plants. Leaf inoculations resulted in higher infection rates than root or crown inoculations. Additionally, inoculations of some resistant cultivars produced infections that were similar to those observed in a field test. The results of this study indicate that the GFP-expressing virus is a useful tool for visualizing virus replication and dynamics, and for understanding resistance mechanisms.

Syncopal-type reactions tend to be delayed and result in falls among elderly blood donors.

BACKGROUND: Delayed syncopal-type complications are infrequent among blood donors, but sometimes have critical consequences, such as severe injury. We retrospectively investigated the characteristics of donors with delayed syncopal-type complications or falls. STUDY DESIGN AND METHODS: We defined a delayed reaction (DR) as syncopal-type complications occurring >20 min after needle removal. Subjects were stratified by sex, age, estimated blood volume (EBV), body mass index (BMI) and frequency of donation. Multiple logistic regression analysis and propensity score weighted M estimation were performed to evaluate the covariate-adjusted risk of syncopal DRs among donors giving 400 ml of whole blood (WB). The DR rate was calculated as the number of DRs divided by the number of all syncopal-type reactions after needle removal. The risk of falls was assessed similarly. Donors who discontinued before completing phlebotomy (donation of 400 ml) were excluded. RESULTS: Among 3818 syncopal-type reactions after needle removal, there were 359 DRs and 93 falls. Elderly donors and female donors with syncopal-type reactions had a significantly higher risk of DRs (P for trend < 0·001). Elderly donors with syncopal-type reactions also had a higher risk of falls (P for trend < 0·001). Among all donors with syncopal-type reactions, the risk of DRs or falls was not correlated with EBV, BMI or donation frequency. CONCLUSION: In female donors and elderly donors (donating 400 ml of WB), syncopal-type reactions tended to be delayed. Elderly donors with syncopal-type reactions had a significantly higher risk of falls.

A genetic analysis of the resistance in barley to Soil-borne wheat mosaic virus.

Soil-borne wheat mosaic virus (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 Polymyxa graminis, 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 analysis revealed that between 33% and 41% of the variation for the measure chosen to represent resistance was under the control of a gene(s) mapping to a region at the distal end of the short arm of chromosome 2H. In contrast to most of the genes known to encode resistance to soil-borne mosaic viruses, the allele specifying resistance was dominant over those present in a susceptible genotype.

Difference in Eye Gaze for Floor Apportionment in Native- and Second-Language Conversations.

In face-to-face communication, eye gaze is known to play various roles such as managing the attention of interlocutors, expressing intimacy, exercising social control, highlighting particular speech content, and coordinating floor apportionment. For second language (L2) communication, one's perception of eye gaze is expected to have more importance than for native language (L1) because eye gaze is assumed to partially compensate for the deficiencies of verbal expressions. This paper examines and clarifies the efficiency of the function of eye gaze in the coordination of floor apportionment through quantitative analyses of eye gaze during three-party conversations in L1 and L2. Specifically, the authors conducted ANOVA tests on the eye-gaze statistics of a speaker and two listeners during utterances while focusing on whether floor-switch occurs subsequent to the utterance. The analysis results show that the listener who is gazed at more by the speaker is more likely to be the next speaker with a higher probability in L2 than in L1 conversations. Meanwhile, the listeners gaze more at the speaker in L2 than in L1 conversation for both the utterances just before a floor switch and cases with no floor switch. These results support the observation that the eye gaze of the speaker is efficient for floor apportionment in L2 conversations and suggest that longer listeners' eye gazes in L2 conversations also function efficiently in smooth floor apportionment.

The two-row malting barley cultivar 'New Sachiho Golden' with null lipoxygenase-1 improves flavor stability in beer and was developed by marker-assisted selection.

Lipoxygenase-1 (LOX-1) null 'New Sachiho Golden' is a two-row malting barley (Hordeum vulgare L.) cultivar released in 2015 that was developed at the Tochigi Prefectural Agricultural Experimental Station by backcross breeding using the high-yield leading cultivar 'Sachiho Golden' as a recurrent parent and the LOX-1 null mutant 'Daikei LM1' as a non-recurrent parent. To develop 'New Sachiho Golden' we used a simple LOX activity assay and marker-assisted selection. This is the first LOX-1 null malting barley cultivar in Japan that is resistant to barley yellow mosaic virus (types I-III). Agronomic characteristics and malting qualities of 'New Sachiho Golden' were similar to those of 'Sachiho Golden', except that 'New Sachiho Golden' had no LOX activity in ungerminated grains and had clearly lower LOX activity during malting than 'Sachiho Golden'. The concentrations of a trans-2-nonenal (T2N) precursor in wort and beer made from 'New Sachiho Golden' were significantly lower than in those made from 'Sachiho Golden', both before and after storage.

Distorted genetic segregation of the transposon mPing at the long arm of chromosome 12 in rice.

A class II transposable element, mPing exists in the rice genome ubiquitously and can transpose even in ordinary cultivation conditions. A copy of mPing was identified at the long arm of chromosome 12. In reciprocal backcrossed F1s between a heterozygote and a homozygote without mPing, the male gametes with this mPing from heterozygotes were transmitted to the next generation at a lower frequency than those without mPing, resulting in distorted genetic segregation in self-fertilized progenies, as well as in F1s after backcrossing. Pollens with mPing tended to germinate on stigma less than those without mPing. These results, however, could not explain the lower transmission of male gametes with mPing. In addition, no excision of mPing was observed in a homozygote. Thus, it was suggested that male gametes with mPing were eliminated partly from pollination to fertilization by negative competition against male gametes without mPing. Less formation of microspores with mPing in meiosis could also be a cause for the distorted segregation, although this could not be examined. At least two ORFs, whose functions have not been identified, are located near this mPing. It is plausible that either of these ORFs or both are necessary for the normal functioning of male gametes.

Partitioning of 13C-labelled photosynthate varies with growth stage and panicle size in high-yielding rice.

A super-high-yielding rice (Oryza sativa L.) cultivar, Takanari, and a traditional japonica rice cultivar, Nakateshinsenbon, were grown under field conditions to compare partitioning of 13C-labelled photosynthate to different plant organs during the period of reproductive development. The flag leaf and the two leaves immediately below it on the main culm were exposed individually to 13CO2 and the movement of the heavy carbon isotope to grains, hull, panicle branches and vegetative parts of plant was assessed. Also, the effect of a reduction of sink size on the partitioning of 13C to different organs was studied by removing some of the primary branches of the panicle. 13C taken up by the three leaves in the post-heading period, moved mostly to the grains and hull of the panicle. At this stage, the uppermost three leaves and the panicle consisted of a single source-sink unit. Partitioning of 13C to the rest of the vegetative structures of the plant was minimal. In the case of Nakateshinsenbon, the flag leaf supplied most of the carbon assimilates for the grains and contributions from the other two leaves were much smaller. However, in Takanari, the contribution of 13C to grains from the second leaf was equivalent to that of the flag leaf. In Takanari, removal of more than one third of the primary branches of the panicle significantly reduced partitioning from the third leaf of the culm, but partitioning from the flag leaf was not significantly changed. In contrast, branch removal treatment significantly depressed transport of carbon assimilates from the flag leaf in Nakateshinsenbon. The obligatory nature of the source-sink relationship in rice is discussed. It is concluded that in lower-yielding traditional rice, photosynthesis in the flag leaf supplies carbon assimilates to the developing grains. But in the super-yielding rice Takanari, the main source area is extended to include the two leaves below the flag leaf so as to sustain an extra large panicle. Even greater grain-filling is possible in super-yielding rice, if the source area is increased further.

An iAc/Ds gene and enhancer trapping system for insertional mutagenesis in rice.

We evaluated a two-component transposon iAc/Ds system for generating a library of insertional mutants in rice. The constructs used have gene or enhancer trapping properties, plasmid rescue and T-DNA/Ds launching pad reporter facilities. Mutagenic iAc/Ds lines were produced by three methods: crossing iAc and Ds containing lines; co-transformation with iAc and Ds constructs; and super-transformation of iAc transgenic calli with Ds constructs. First and second generation screening populations, derived from crosses (F2 and F3) or double transformation (DtT1 and DtT2), were analysed for stable insertion lines containing Ds transposed to locations unlinked to iAc. The average frequencies of putative stable insertion (PSI) lines in the F2, DtT1, F3 and DtT2 populations were 6.61, 5.58, 11.47 and 7.05% respectively, with large variations in these frequencies in screening populations derived from different mutagenic lines. Further analyses indicated that 41, 33, 65 and 64% of the PSI lines, respectively, have Ds transposed to locations unlinked to the original Ds launching pad. Using the plasmid rescue system, sequences flanking Ds from 137 PSI lines were obtained. Sixty-eight of these lines had unique insertions in genomic regions, of which 18 were known sequences. Because the average frequency of proven stable insertion lines in any of our screening populations has been less than 5%, we suggest that additional features should be incorporated in this two-component iAc/Ds system to increase the screening efficiency, and to make it suitable for large-scale insertional mutagenesis and determination of gene function in rice.