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In this paper we survey some results on the symmetric semi-perfect obstruction theory on a Deligne—Mumford stack X constructed by Chang—Li, and Behrend's theorem equating the weighted Euler characteristic of X and the virtual count of X by symmetric semi-perfect obstruction theories. As an application, we prove that Joyce's d-critical scheme admits a symmetric semi-perfect obstruction theory, which can be applied to the virtual Euler characteristics by Jiang—Thomas. [ABSTRACT FROM AUTHOR]

We provide a construction of the moduli space of stable coherent sheaves in the world of non-archimedean geometry, where we use the notion of Berkovich non-archimedean analytic spaces. The motivation for our construction is Tony Yue Yu's non-archimedean enumerative geometry in Gromov—Witten theory. The construction of the moduli space of stable sheaves using Berkovich analytic spaces will give rise to the non-archimedean version of Donaldson—Thomas invariants. In this paper we give the moduli construction over a non-archimedean field K . We use the machinery of formal schemes, that is, we define and construct the formal moduli stack of (semi)-stable coherent sheaves over a discrete valuation ring R, and taking generic fiber we get the non-archimedean analytic moduli space of semistable coherent sheaves over the fractional non-archimedean field K . We generalize Joyce's d-critical scheme structure in [37] or Kiem—Li's virtual critical manifolds in [38] to the world of formal schemes, and Berkovich non-archimedean analytic spaces. As an application, we provide a proof for the motivic localization formula for a d-critical non-archimedean K -analytic space using global motive of vanishing cycles and motivic integration on oriented formal d-critical schemes. This generalizes Maulik's motivic localization formula for the motivic Donaldson—Thomas invariants. [ABSTRACT FROM AUTHOR]

We present the quasiparticle band structure and the optical excitation spectrum of bulk LiCl, using many-body perturbation theory. Density-functional theory is used to calculate the ground-state geometry of the system. The quasiparticle band structure is calculated within the GW approximation. Taking the electron-hole interaction into consideration, electron-hole pair states and optical excitations are obtained by solving the Bethe-Salpeter equation for the electron-hole two-particle Green function. The calculated band gap is 9.5 eV, which is in good agreement with the experimental result of 9.4 eV. And the calculated optical absorption spectrum, which contains an exciton peak at 8.8 eV and a resonant-exciton peak at 9.8 eV, is also in good agreement with experimental data. [ABSTRACT FROM AUTHOR]

Summary: De‐domestication is a unique evolutionary process during which crops re‐acquire wild‐like traits to survive and persist in agricultural fields without the need for human cultivation. The re‐acquisition of seed dispersal mechanisms is crucial for crop de‐domestication. Common wheat is an important cereal crop worldwide. Tibetan semi‐wild wheat is a potential de‐domesticated common wheat subspecies. However, the crucial genes responsible for its brittle rachis trait have not been identified.Genetic mapping, functional analyses and phylogenetic analyses were completed to identify the gene associated with Qbr.sau‐5A, which is a major locus for the brittle rachis trait of Tibetan semi‐wild wheat.The cloned Qbr.sau‐5A gene is a new Q allele (Qt) with a 161‐bp transposon insertion in exon 5. Although Qt is expressed normally, its encoded peptide lacks some key features of the APETALA2 family. The abnormal functions of Qt in developing wheat spikes result in brittle rachises. Phylogenetic and genotyping analyses confirmed that Qt originated from Q in common wheat and is naturally distributed only in Tibetan semi‐wild wheat populations.The identification of Qt provides new evidence regarding the origin of Tibetan semi‐wild wheat, and new insights into the re‐acquisition of wild traits during crop de‐domestication. See also the Commentary on this article by Ellstrand, 224: 550–551. [ABSTRACT FROM AUTHOR]

Background: Phytohormones are key regulators of plant growth, development, and signalling networks involved in responses to diverse biotic and abiotic stresses. Transcriptional reference maps of hormone responses have been reported for several model plant species such as Arabidopsis thaliana, Oryza sativa, and Brachypodium distachyon. However, because of species differences and the complexity of the wheat genome, these transcriptome data are not appropriate reference material for wheat studies. Results: We comprehensively analysed the transcriptomic responses in wheat spikes to seven phytohormones, including indole acetic acid (IAA), gibberellic acid (GA), abscisic acid (ABA), ethylene (ET), cytokinin (CK), salicylic acid (SA), and methyl jasmonic acid (MeJA). A total of 3386 genes were differentially expressed at 24 h after the hormone treatments. Furthermore, 22.7% of these genes exhibited overlapping transcriptional responses for at least two hormones, implying there is crosstalk among phytohormones. We subsequently identified genes with expression levels that were significantly and differentially induced by a specific phytohormone (i.e., hormone-specific responses). The data for these hormone-responsive genes were then compared with the transcriptome data for wheat spikes exposed to biotic (Fusarium head blight) and abiotic (water deficit) stresses. Conclusion: Our data were used to develop a transcriptional reference map of hormone responses in wheat spikes. [ABSTRACT FROM AUTHOR]

Hairiness is a common character in planta. Glume hairiness (Hg) is present in the full spectrum of bread wheat and its close relatives and was mainly studied in phenotypic diversity, species evolution, and mapping as a morphological marker. Previous studies indicated that Hg was controlled by a single dominant gene Hg on the short arm of chromosome 1A. However, to date, systematic and comprehensive study of Hg is not available; and markers flanking Hg were rather limited as well, hindering the fine mapping and even cloning of this gene. In the study reported here, aiming at genetically analyze Hg gene systematically, a linkage map of a recombinant inbred line (RIL) generated from the cross between the Tibetan semi-wild wheat ( Triticum aestivum subsp. tibetanum Shao) Q1028 and a cultivated wheat Zhengmai 9023 (ZM9023) was constructed using diversity array technology (DArT) and reported simple sequence repeat (SSR) markers. Five SSR markers (saufc2, saufc9, saufc17, saufc25, saufc90) were further developed to accurately locate Hg in this study. Of these five SSR markers all linked to Hg, saufc2 was genetically most closed to Hg with a distance of 1.6 cM. The effectiveness of the five newly developed SSR markers were validated in another RIL derived from Q1028 and a cultivated line 99E18. To our knowledge, this is the first report on fine mapping of Hg in bread wheat. The accurate localization of the Hg and the development of the markers flanked it should facilitate the cloning of this gene and further the study of its possible physiological function in bread wheat. [ABSTRACT FROM AUTHOR]

A (3+1)-dimensional variable-coefficient coupled nonlinear Schrödinger equation in parity-time symmetric inhomogeneous nonlinear couplers with gain and loss is studied, and the $${\mathcal {PT}}$$ -symmetric and $${\mathcal {PT}}$$ -antisymmetric combined Kuznetsov-Ma soliton solutions are obtained via the Darboux transformation method. Nonlinear tunnelling effect of controllable combined Kuznetsov-Ma solitons such as their restraint, maintenance and postpone are discussed when they pass through the dispersion/diffraction barrier and well. [ABSTRACT FROM AUTHOR]

Tibetan semi-wild wheat ( Triticum aestivum ssp. tibetanum Shao) is a hexaploid wheat resource distributed only in Tibet that has an interesting type of seed dormancy in addition to hulled glumes and brittle spikelets. A whole-genome linkage map of T. aestivum ssp. tibetanum was constructed for a population of 186 recombinant inbred lines using 645 diversity array technology (DArT) markers, 127 simple sequence repeat markers and three R- 1 genotyping markers. Seed dormancy was evaluated at five post-ripening stages from 2010 to 2013. Comprehensive quantitative trait locus (QTL) mapping by inclusive composite interval mapping analysis identified seven QTLs for seed dormancy, designated as Qsd.sau- 1B, Qsd.sau- 3A, Qsd.sau- 3B, Qsd.sau- 3D, Qsd.sau- 4A1, Qsd.sau- 4A2, and Qsd.sau- 7A, on chromosomes 1BL, 3AL, 3BL, 3DL, 4AS, 4AL, and 7AL, which explained 8.9, 7.2, 10.8, 7.0, 11.4, 9.4, and 12.7 % of phenotypic variation, respectively. Qsd.sau- 4A1 and Qsd.sau- 7A have only rarely been reported in domesticated common wheat but were prominent in T. aestivum ssp. tibetanum accession Q1028. Qsd.sau- 4A1 was associated with intense, short-duration dormancy and was recognized as an ideal QTL for wheat breeding. [ABSTRACT FROM AUTHOR]

Tibetan semi-wild wheat (Triticum aestivum ssp. tibetanum Shao) is a semi-wild hexaploid wheat resource that is only naturally distributed in the Qinghai-Tibet Plateau. Brittle rachis and hard threshing are two important characters of Tibetan semi-wild wheat. A whole-genome linkage map of T. aestivum ssp. tibetanum was constructed using a recombinant inbred line population (Q1028×ZM9023) with 186 lines, 564 diversity array technology markers, and 117 simple sequence repeat markers. Phenotypic data on brittle rachis and threshability, as two quantitative traits, were evaluated on the basis of the number of average spike rachis fragments per spike and percent threshability in 2012 and 2013, respectively. Quantitative trait locus (QTL) mapping performed using inclusive composite interval mapping analysis clearly identified four QTLs for brittle rachis and three QTLs for threshability. However, three loci on 2DS, 2DL, and 5AL showed pleiotropism for brittle rachis and threshability; they respectively explained 5.3%, 18.6%, and 18.6% of phenotypic variation for brittle rachis and 17.4%, 13.2%, and 35.2% of phenotypic variation for threshability. A locus on 3DS showed an independent effect on brittle rachis, which explained 38.7% of the phenotypic variation. The loci on 2DS and 3DS probably represented the effect of Tg and Br1, respectively. The locus on 5AL was in very close proximity to the Q gene, but was different from the predicted q in Tibetan semi-wild wheat. To our knowledge, the locus on 2DL has never been reported in common wheat but was prominent in T. aestivum ssp. tibetanum accession Q1028. It remarkably interacted with the locus on 5AL to affect brittle rachis. Several major loci for brittle rachis and threshability were identified in Tibetan semi-wild wheat, improving the understanding of these two characters and suggesting the occurrence of special evolution in Tibetan semi-wild wheat. [ABSTRACT FROM AUTHOR]

We report the quasiparticle band structure and optical absorption spectrum of bulk LiBr calculated from first-principles approaches. The quasiparticle band structure is calculated within the GW approximation. Taking the electron-hole interaction into consideration, the optical excitation is investigated by solving the Bethe-Salpeter equation for the electron-hole two-particle Green's function. The obtained results for the band gap and optical absorption spectrum are in good agreement with experimental measurements. [ABSTRACT FROM AUTHOR]

Bombyx mori cytoplasmic polyhedrosis virus (BmCPV) is one of the major viral pathogens for the silkworm. To date, the molecular mechanism of BmCPV invasion has been unclear. We cloned the full length complementary (c)DNA which encodes the ubiquitin-activating enzyme E1-domain containing protein1 (UbE1DC1) of Bombyx mori by using suppression subtractive hybridization (SSH) and rapid amplification of complementary (c)DNA ends (RACE). The full-length cDNA of UbE1DC1gene is 1 919 bp, consisting of a 100 bp 5′ untranslated region, a 637 bp 3′ untranslated region and an 1 182 bp open reading frame (ORF), encoding a 393 amino acid protein. The protein contained the THiF_MoeB_hesA_family domain, an adenosine triphosphate binding site, which belongs to the family of ubiquitin-activating enzyme E1. Reverse transcription – polymerase chain reaction analysis from the silkworm tissues, namely silk gland, hemocyte, fat body, gonad and midgut revealed that UbE1DC1 was expressed in all the five tissues. The real-time quantitative polymerase chain reaction analysis indicated that the relative expression of UbE1DC1 in the normal midgut was approximately 9.78-fold of that in the BmCPV-infected midgut. It is implicated that UbE1DC1 may play an important role in the interaction between the host and BmCPV invasion. [ABSTRACT FROM AUTHOR]

Fusarium graminearum causes Fusarium head blight (FHB), a devastating disease of wheat. Salicylic acid (SA) is involved in the resistance of wheat to F. graminearum. Cell wall mannoprotein (CWM) is known to trigger defense responses in plants, but its role in the pathogenicity of F. graminearum remains unclear. Here, we characterized FgCWM1 (FG05_11315), encoding a CWM in F. graminearum. FgCWM1 was highly expressed in wheat spikes by 24 h after initial inoculation and was upregulated by SA. Disruption of FgCWM1 (ΔFgCWM1) reduced mannose and protein accumulation in the fungal cell wall, especially under SA treatment, and resulted in defective fungal cell walls, leading to increased fungal sensitivity to SA. The positive role of FgCWM1 in mannose and protein accumulation was confirmed by its expression in Saccharomyces cerevisiae. Compared with wild type (WT), ΔFgCWM1 exhibited reduced pathogenicity toward wheat, but it produced the same amount of deoxynivalenol both in culture and in spikes. Complementation of ΔFgCWM1 with FgCWM1 restored the WT phenotype. Localization analyses revealed that FgCWM1 was distributed on the cell wall, consistent with its structural role. Thus, FgCWM1 encodes a CWM protein that plays an important role in the cell wall integrity and pathogenicity of F. graminearum. [ABSTRACT FROM AUTHOR]

Salicylic acid (SA) is a key defense hormone associated with wheat resistance against Fusarium head blight, which is a severe disease mainly caused by Fusarium graminearum. Although F. graminearum can metabolize SA, it remains unclear how this metabolic activity affects the wheat–F. graminearum interaction. In this study, we identified a salicylate hydroxylase gene (FG05_08116; FgNahG) in F. graminearum. This gene encodes a protein that catalyzes the conversion of SA to catechol. Additionally, FgNahG was widely distributed within hyphae. Disrupting the FgNahG gene (ΔFgNahG) led to enhanced sensitivity to SA, increased accumulation of SA in wheat spikes during the early infection stage and inhibited development of head blight symptoms. However, FgNahG did not affect mycotoxin production. Re-introducing a functional FgNahG gene into the ΔFgNahG mutant recovered the wild-type phenotype. Moreover, the expression of FgNahG in transgenic Arabidopsis thaliana decreased the SA concentration and the resistance of leaves to F. graminearum. These results indicate that the endogenous SA in wheat influences the resistance against F. graminearum. Furthermore, the capacity to metabolize SA is an important factor affecting the ability of F. graminearum to infect wheat plants. [ABSTRACT FROM AUTHOR]

ATP-binding cassette (ABC) transporters hydrolyze ATP to transport a wide range of substrates. Fusarium graminearum is a major causal agent of Fusarium head blight, which is a severe disease in wheat worldwide. FgABCC9 (FG05_07325) encodes an ABC-C (ABC transporter family C) transporter in F. graminearum, which was highly expressed during the infection in wheat and was up-regulated by the plant defense hormone salicylic acid (SA) and the fungicide tebuconazole. The predicted tertiary structure of the FgABCC9 protein was consistent with the schematic of the ABC exporter. Deletion of FgABCC9 resulted in decreased mycelial growth, increased sensitivity to SA and tebuconazole, reduced accumulation of deoxynivalenol (DON), and less pathogenicity towards wheat. Re-introduction of a functional FgABCC9 gene into ΔFgABCC9 recovered the phenotypes of the wild type strain. Transgenic expression of FgABCC9 in Arabidopsis thaliana increased the accumulation of SA in its leaves without activating SA signaling, which suggests that FgABCC9 functions as an SA exporter. Taken together, FgABCC9 encodes an ABC exporter, which is critical for fungal exportation of SA, response to tebuconazole, mycelial growth, and pathogenicity towards wheat. [ABSTRACT FROM AUTHOR]