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Summary: Fusarium head blight (FHB) and the presence of mycotoxin deoxynivalenol (DON) pose serious threats to wheat production and food safety worldwide. DON, as a virulence factor, is crucial for the spread of FHB pathogens on plants. However, germplasm resources that are naturally resistant to DON and DON‐producing FHB pathogens are inadequate in plants. Here, detoxifying bacteria genes responsible for DON epimerization were used to enhance the resistance of wheat to mycotoxin DON and FHB pathogens. We characterized the complete pathway and molecular basis leading to the thorough detoxification of DON via epimerization through two sequential reactions in the detoxifying bacterium Devosia sp. D6‐9. Epimerization efficiently eliminates the phytotoxicity of DON and neutralizes the effects of DON as a virulence factor. Notably, co‐expressing of the genes encoding quinoprotein dehydrogenase (QDDH) for DON oxidation in the first reaction step, and aldo‐keto reductase AKR13B2 for 3‐keto‐DON reduction in the second reaction step significantly reduced the accumulation of DON as virulence factor in wheat after the infection of pathogenic Fusarium, and accordingly conferred increased disease resistance to FHB by restricting the spread of pathogenic Fusarium in the transgenic plants. Stable and improved resistance was observed in greenhouse and field conditions over multiple generations. This successful approach presents a promising avenue for enhancing FHB resistance in crops and reducing mycotoxin contents in grains through detoxification of the virulence factor DON by exogenous resistance genes from microbes. [ABSTRACT FROM AUTHOR]

The dominant species of a biome can be regarded as its genuine indicator. Evergreen broadleaved forests (EBLFs) in subtropical East Asia harbor high levels of species biodiversity and endemism and are vital to regional carbon storage and cycling. However, the historical assembly of this unique biome is still controversial. Fagaceae is the most essential family in East Asian subtropical EBLFs and its dominant species are vital for the existence of this biome. Here, we used the dominant Fagaceae species to shed light on the dynamic process of East Asian subtropical EBLFs over time. Our results indicate high precipitation in summer and low temperature in winter are the most influential climatic factors for the distribution of East Asian subtropical EBLFs. Modern East Asian subtropical EBLFs did not begin to appear until 23 Ma, subsequently experienced a long‐lasting development in the Miocene and markedly deteriorated at about 4 Ma, driven jointly by orogenesis and paleoclimate. We also document that there is a lag time between when one clade invaded the region and when its members become dominant species within the region. This study may improve our ability to predict and mitigate the threats to biodiversity of East Asian subtropical EBLFs and points to a new path for future studies involving multidisciplinary methods to explore the assembly of regional biomes. [ABSTRACT FROM AUTHOR]

In this article, a quasi‐continuous ratio gradient alloy steel (GAS) with a 24CrNiMo high‐strength low‐alloy steel matrix for high‐speed railway brake discs is fabricated by selective laser melting (SLM). The composition of GAS is X% 24CrNiMo + (1–X)% wear‐resistant stainless steel (WSS), in which X is 100, 65, 35, and 0. The relationship between the microstructure and the corrosion resistance is intensively studied by electron backscatter diffraction (EBSD) and potentiodynamic electrochemical equipment. With the increase in the content of WSS, the low angle grain boundaries of the GAS increases, and the microstructure refines and the texture intensity decreases. The passivation film of the external WSS strengthening layer is dense; the corresponding corrosion potential and corrosion current density are −0.109 V and 2.08 × 10−8 A cm−2, respectively. The corrosion current density is about 1% of the substrate 24CrNiMo, and the corrosion resistance of the material is significantly improved. [ABSTRACT FROM AUTHOR]

Summary: MicroRNA‐like RNAs (milRNAs) post‐transcriptionally down‐regulate target genes. We investigated Fusarium graminearum (Fg) milRNA expression during fungal vegetative growth and infection of wheat. Small RNA sequencing identified 36 milRNAs from Fg, one of which, Fgmil‐2, had >100 transcripts per million in conidia, mycelia and infected wheat, with the highest expression in conidia and the lowest expression in colonized wheat tissue. Fgmil‐2 displays perfect homology to the 3ʹ‐untranslated region (3ʹ‐UTR) of an FgbioH1 messenger RNA that is involved in biotin biosynthesis. Poly(A) polymerase‐mediated rapid amplification of cDNA ends combined with sequencing analysis demonstrated that cleavage at a specific site by FgDicer2 in the 3ʹ‐UTR of FgbioH1 transcripts generated the Fgmil‐2 precursor with a typical hairpin structure. Deletion of FgbioH1 or FgDicer2 genes abolished Fgmil‐2 biogenesis. FgbioH1 had an inversely correlated pattern of expression to that of Fgmil‐2 and FgDicer2. Deletion of FgbioH1 also showed that it is required for mycelial growth, virulence, mycotoxin biosynthesis and expression of biotin‐dependent carboxylase genes. This study reveals in Fg a novel mode of inversely correlated post‐transcriptional regulation in which Fgmil‐2 originates from its own target transcript, FgbioH, to govern biotin biosynthesis. [ABSTRACT FROM AUTHOR]

Plasma homocysteine (Hcy) levels are associated with elevated blood pressure. However, the causal association between Hcy levels and the risk of hypertension remains ambiguous. Taking the study design effect into consideration, this study aimed to investigate this issue through a cross-sectional and longitudinal analysis. Data were obtained from the Beijing Health Management Cohort study, which conducted routine health check-ups from 2012 to 2017. Multivariate logistic regression was used for the cross-sectional analysis, and a quadratic inference function approach was performed for the longitudinal analysis. A total of 30 376 subjects (mean age = 50.0 years) were included in the cross-sectional analysis, and a subgroup of 3913 subjects without hypertension at baseline was included in the longitudinal analysis. After adjusting for potential confounders, the risk of hypertension increased with Hcy levels in the cross-sectional analysis using the traditional definition of hypertension (OR = 1.262, 95% CI: 1.155-1.378, Q2 vs Q1; OR = 1.458, 95% CI: 1.335-1.593, Q3 vs Q1; OR = 1.520, 95% CI: 1.388-1.664, Q4 vs Q1) and the 2017 hypertension definition (OR = 1.159, 95% CI: 1.067-1.259, Q2 vs Q1; OR = 1.328, 95% CI: 1.221-1.445, Q3 vs Q1; OR = 1.328, 95% CI: 1.217-1.449, Q4 vs Q1). The longitudinal analysis showed that hypertension risk increased in the third quartile of Hcy (OR = 1.268, 95% CI: 1.030-1.560, Q3 vs Q1). Elevated total plasma Hcy may be used as a predictive biomarker for hypertension. Attention should be paid to gender-specific mechanisms when issuing precise precautions. [ABSTRACT FROM AUTHOR]

We reconstructed a phylogenetic tree of Chinese vascular plants (Tracheophyta) using sequences of the chloroplast genes atpB, matK, ndhF, and rbcL and mitochondrial matR. We produced a matrix comprising 6098 species and including 13 695 DNA sequences, of which 1803 were newly generated. Our taxonomic sampling spanned 3114 genera representing 323 families of Chinese vascular plants, covering more than 93% of all genera known from China. The comprehensive large phylogeny supports most relationships among and within families recognized by recent molecular phylogenetic studies for lycophytes, ferns (monilophytes), gymnosperms, and angiosperms. For angiosperms, most families in Angiosperm Phylogeny Group IV are supported as monophyletic, except for a paraphyletic Dipterocarpaceae and Santalaceae. The infrafamilial relationships of several large families and monophyly of some large genera are well supported by our dense taxonomic sampling. Our results showed that two species of Eberhardtia are sister to a clade formed by all other taxa of Sapotaceae, except Sarcosperma. We have made our phylogeny of Chinese vascular plants publically available for the creation of subtrees via SoTree (), an automated phylogeny assembly tool for ecologists. [ABSTRACT FROM AUTHOR]

There has been increasing interest in integrating a regional tree of life with community assembly rules in the ecological research. This raises questions regarding the impacts of taxon sampling strategies at the regional versus global scales on the topology. To address this concern, we constructed two trees for the nitrogen-fixing clade: (i) a genus-level global tree including 1023 genera; and (ii) a regional tree comprising 303 genera, with taxon sampling limited to China. We used the supermatrix approach and performed maximum likelihood analyses on combined matK, rbcL, and trnL-F plastid sequences. We found that the topology of the global and the regional tree of the N-fixing clade were generally congruent. However, whereas relationships among the four orders obtained with the global tree agreed with the accepted topology obtained in focused analyses with more genes, the regional topology obtained different relationships, albeit weakly supported. At a finer scale, the phylogenetic position of the family Myricaceae was found to be sensitive to sampling density. We expect that internal support throughout the phylogeny could be improved with denser taxon sampling. The taxon sampling approach (global vs. regional) did not have a major impact on fine-level branching patterns of the N-fixing clade. Thus, a well-resolved phylogeny with relatively dense taxon sampling strategy at the regional scale appears, in this case, to be a good representation of the overall phylogenetic pattern and could be used in ecological research. Otherwise, the regional tree should be adjusted according to the correspondingly reliable global tree. [ABSTRACT FROM AUTHOR]

Plant germplasm resources with natural resistance against globally important toxigenic Fusarium are inadequate. CWP2, a Fusarium genus-specific antibody, confers durable resistance to different Fusarium pathogens that infect cereals and other crops, producing mycotoxins. However, the nature of the CWP2 target is not known. Thus, investigation of the gene coding for the CWP2 antibody target will likely provide critical insights into the mechanism underlying the resistance mediated by this disease-resistance antibody., Immunoblots and mass spectrometry analysis of two-dimensional electrophoresis gels containing cell wall proteins from Fusarium graminearum ( Fg) revealed that a glyoxal oxidase ( GLX) is the CWP2 antigen. Cellular localization studies showed that GLX is localized to the plasma membrane., This GLX efficiently catalyzes hydrogen peroxide production; this enzymatic activity was specifically inhibited by the CWP2 antibody. GLX-deletion strains of Fg, F. verticillioides ( Fv) and F. oxysporum had significantly reduced virulence on plants. The GLX-deletion Fg and Fv strains had markedly reduced mycotoxin accumulation, and the expression of key genes in mycotoxin metabolism was downregulated., This study reveals a single gene-encoded and highly conserved cellular surface antigen that is specifically recognized by the disease-resistance antibody CWP2 and regulates both virulence and mycotoxin biosynthesis in Fusarium species. [ABSTRACT FROM AUTHOR]

Fusarium head blight (FHB) and Fusarium seedling blight (FSB) of wheat, caused by Fusarium pathogens, are devastating diseases worldwide. We report the expression of RNA interference (RNAi) sequences derived from an essential Fusarium graminearum (Fg) virulence gene, chitin synthase (Chs) 3b, as a method to enhance resistance of wheat plants to fungal pathogens. Deletion of Chs3b was lethal to Fg; disruption of the other Chs gene family members generated knockout mutants with diverse impacts on Fg. Comparative expression analyses revealed that among the Chs gene family members, Chs3b had the highest expression levels during Fg colonization of wheat. Three hairpin RNAi constructs corresponding to the different regions of Chs3b were found to silence Chs3b in transgenic Fg strains. Co-expression of these three RNAi constructs in two independent elite wheat cultivar transgenic lines conferred high levels of stable, consistent resistance (combined type I and II resistance) to both FHB and FSB throughout the T3 to T5 generations. Confocal microscopy revealed profoundly restricted mycelia in Fginfected transgenic wheat plants. Presence of the three specific short interfering RNAs in transgenic wheat plants was confirmed by Northern blotting, and these RNAs efficiently downregulated Chs3b in the colonizing Fusarium pathogens on wheat seedlings and spikes. Our results demonstrate that host-induced gene silencing of an essential fungal chitin synthase gene is an effective strategy for enhancing resistance in crop plants under field test conditions. [ABSTRACT FROM AUTHOR]

Fusarium head blight ( FHB) in wheat and other small grain cereals is a globally devastating disease caused by toxigenic Fusarium pathogens. Controlling FHB is a challenge because germplasm that is naturally resistant against these pathogens is inadequate. Current control measures rely on fungicides. Here, an antibody fusion comprised of the Fusarium spp.-specific recombinant antibody gene CWP2 derived from chicken, and the endochitinase gene Ech42 from the biocontrol fungus Trichoderma atroviride was introduced into the elite wheat cultivar Zhengmai9023 by particle bombardment. Expression of this fusion gene was regulated by the lemma/palea-specific promoter Lem2 derived from barley; its expression was confirmed as lemma/palea-specific in transgenic wheat. Single-floret inoculation of independent transgenic wheat lines of the T3 to T6 generations revealed significant resistance (type II) to fungal spreading, and natural infection assays in the field showed significant resistance (type I) to initial infection. Gas chromatography-mass spectrometry analysis revealed marked reduction of mycotoxins in the grains of the transgenic wheat lines. Progenies of crosses between the transgenic lines and the FHB-susceptible cultivar Huamai13 also showed significantly enhanced FHB resistance. Quantitative real-time PCR analysis revealed that the tissue-specific expression of the antibody fusion was induced by salicylic acid drenching and induced to a greater extent by F. graminearum infection. Histochemical analysis showed substantial restriction of mycelial growth in the lemma tissues of the transgenic plants. Thus, the combined tissue-specific and pathogen-inducible expression of this Fusarium-specific antibody fusion can effectively protect wheat against Fusarium pathogens and reduce mycotoxin content in grain. [ABSTRACT FROM AUTHOR]

A recently isolated Fusarium population from maize in Belgium was identified as a new species, Fusarium temperatum. From a survey of Fusarium species associated with maize ear rot in nineteen provinces in 2009 in China, ten strains isolated from Guizhou and Hubei provinces were identified as F. temperatum. Morphological and molecular phylogenetic analyses based on the DNA sequences of individual translation elongation factor 1-alpha and β-tubulin genes revealed that the recovered isolates produced macroconidia typical of four-septate with a foot-shaped basal cell and belonged to F. temperatum that is distinctly different from its most closely related species F. subglutinans and others within Gibberella fujikuroi complex species from maize. All the strains from this newly isolated species were able to infect maize and wheat in field, with higher pathogenicity on maize. Mycotoxin determination of maize grains infected by the strains under natural field condition by ultra-high-performance liquid chromatography-tandem mass spectrometry and gas chromatography-mass spectrometry analyses showed that among fifteen mycotoxins assayed, two mycotoxins fumonisin B1 and B2 ranging from 9.26 to 166.89 μg/g were detected, with massively more FB2 mycotoxin (2.8- to 108.8-fold) than FB1. This mycotoxin production profile is different from that of the Belgian population in which only fumonisin B1 was barely detected in one of eleven strains assayed. Comparative analyses of the F. temperatum and F. subglutinans strains showed that the highest fumonisin producers were present among the F. temperatum population, which were also the most pathogenic to maize. These results suggested a need for proper monitoring and controlling this species in the relevant maize-growing regions. [ABSTRACT FROM AUTHOR]

Fusarium graminearum clade species are among the main causative agents of Gibberella ear rot (GER) in maize and responsible for the various trichothecene mycotoxins accumulated in contaminated maize grains. In this study, a total of 620 isolates from diseased maize ears collected from 59 districts in 19 provinces throughout China, previously identified morphologically as Fusarium graminearum clade, was genetically characterized at the species level based on SCAR (Sequence Characterized Amplified Region) and for their potential capability of mycotoxin production using the genetic chemotyping assay. The results showed that 359 isolates were F. asiaticum (SCAR 5), which consisted of 97% nivalenol (NIV)-chemotypes, 0.8% 3-acetyldeoxynivalenol (3-ADON)-producing isolates and 2.2% 15-acetyldeoxynivalenol (15-ADON) producers, whereas the remaining 261 isolates were identified as F. graminearum sensu stricto (SCAR 1), all of which produced 15-ADON mycotoxins. This high proportion of NIV producers present in F. asiaticum is different from the chemotype patterns in F. asiaticum populations isolated from wheat and barley, where DON and its acetylated chemotypes were the predominant mycotoxins. Moreover, the majority of NIV producers (59.1%) and all the 3-ADON-producing strains were derived from the warmer regions in southern China, whereas most of the 15-ADON-producing strains (78.4%) were isolated from the colder regions in northern China. Our study is the first report of NIV chemotypes of F. asiaticum and 15-ADON chemotypes of F. graminearum sensu stricto that were associated with the GER of maize in China. [ABSTRACT FROM AUTHOR]

Vaccination with antigenic peptide-pulsed antigen-presenting cells (APC) represents an attractive approach for therapy for cancer and diseases caused by intracellular infections. It has been suggested that sufficient stable MHC/peptide complexes on the surface of APC might play an important role in the generation of antitumor and antiviral immunity in vivo. In this study, we observed that exogenous peptides that were artificially fused with an endoplasmic reticulum (ER) retrieval signal, a C-terminal Lys-Asp-Glu-Leu sequence, could be efficiently presented by intracellular MHC class I molecules in a TAP- and proteasome-independent, but brefeldin A-sensitive manner. The APC retained the capacity to display surface MHC/peptide complexes for a prolonged period. In addition, our results show that vaccination with DC bearing our fusion peptides induced greatly enhanced specific CTL response, and resulted in significant inhibition of tumor growth. Thus, the ER retrieval signal modification can be regarded as a novel method for targeting exogenous peptides into the intracellular MHC class I presentation pathway, and may improve the clinical utility of vaccines based on synthetic peptide pulsed DC. [ABSTRACT FROM AUTHOR]