Genetic analysis of stripe rust resistance in the common wheat line Kfa/2*Kachu under a Chinese rust environment.

KEY MESSAGE: We mapped a new race-specific seedling stripe rust resistance gene on wheat chromosome 5BL and a new APR locus QYr.hazu-2BS from CIMMYT wheat line Kfa/2*Kachu. Breeding resistant wheat (Triticum aestivum) varieties is the most economical and efficient way to manage wheat stripe rust, but requires the prior identification of new resistance genes and development of associated molecular markers for marker-assisted selection. To map stripe rust resistance loci in wheat, we used a recombinant inbred line population generated by crossing the stripe rust-resistant parent 'Kfa/2*Kachu' and the susceptible parent 'Apav#1'. We employed genotyping-by-sequencing and bulked segregant RNA sequencing to map a new race-specific seedling stripe rust resistance gene, which we designated YrK, to wheat chromosome arm 5BL. TraesCS5B02G330700 encodes a receptor-like kinase and is a high-confidence candidate gene for YrK based on virus-induced gene silencing results and the significant induction of its expression 24 h after inoculation with wheat stripe rust. To assist breeding, we developed functional molecular markers based on the polymorphic single nucleotide polymorphisms in the coding sequence region of YrK. We also mapped four adult plant resistance (APR) loci to wheat chromosome arms 1BL, 2AS, 2BS and 4AL. Among these APR loci, we determined that QYr.hazu-1BL and QYr.hazu-2AS are allelic to the known pleiotropic resistance gene Lr46/Yr29/Pm39 and the race-specific gene Yr17, respectively. However, QYr.hazu-2BS is likely a new APR locus, for which we converted closely linked SNP polymorphisms into breeder-friendly Kompetitive allele-specific PCR (KASP) markers. In the present study, we provided new stripe rust resistance locus/gene and molecular markers for wheat breeder to develop rust-resistant wheat variety.

Identification of Two New Loci for Adult Plant Resistance to Leaf Rust and Stripe Rust in the Chinese Wheat Variety 'Neimai 836'.

The characterization of leaf rust (caused by Puccinia triticina) and stripe rust (caused by Puccinia striiformis f. sp. tritici) resistance genes is the basis for breeding resistant wheat varieties and managing epidemics of these diseases in wheat. A cross between the susceptible wheat variety 'Apav#1' and resistant variety 'Neimai 836' was used to develop a mapping population containing 148 F5 recombinant inbred lines (RILs). Leaf rust phenotyping was done in field trials at Ciudad Obregón, Mexico, in 2017 and 2018, and stripe rust data were generated at Toluca, Mexico, in 2017 and in Mianyang, Ezhou, and Gansu, China, in 2019. Inclusive complete interval mapping (ICIM) was used to create a genetic map and identify significant resistance quantitative trait loci (QTL) with 2,350 polymorphic markers from a 15K wheat single-nucleotide polymorphism (SNP) array and simple-sequence repeats (SSRs). The pleiotropic multipathogen resistance gene Lr46/Yr29 and four QTL were identified, including two new loci, QLr.hzau-3BL and QYr.hzau-5AL, which explained 3 to 16% of the phenotypic variation in resistance to leaf rust and 7 to 14% of that to stripe rust. The flanking SNP markers for the two loci were converted to Kompetitive Allele-Specific PCR (KASP) markers and used to genotype a collection of 153 wheat lines, indicating the Chinese origin of the loci. Our results suggest that Neimai 836, which has been used as a parent for many wheat varieties in China, could be a useful source of high-level resistance to both leaf rust and stripe rust.

Four Consistent Loci Confer Adult Plant Resistance to Leaf Rust in the Durum Wheat Lines Heller#1 and Dunkler.

The durum wheat lines Heller#1 and Dunkler from the International Maize and Wheat Improvement Center Global Wheat Program showed moderate and stable adult plant resistance to leaf rust under high disease pressure over field environments in northwestern Mexico. Leaf rust phenotyping was performed on two recombinant inbred line (RIL) populations derived from crosses of Heller#1 and Dunkler with the susceptible parent Atred#2, conducted under artificially induced Puccinia triticina epidemics in 2013, 2014, 2015, and 2016. The Atred#2 × Heller#1 and Atred#2 × Dunkler populations were genotyped by single nucleotide polymorphism (SNP) platforms and diversity arrays technology markers, respectively. Four leaf rust resistance quantitative trait loci were detected simultaneously in the two RIL populations: Lr46, QLr.cim-2BC, QLr.cim-5BL, and QLr.cim-6BL based on phenotypic data across all four crop seasons. They explained 11.7 to 46.8%, 7.2 to 26.1%, 8.4 to 24.1%, and 12.4 to 28.5%, respectively, of the phenotypic variation for leaf rust resistance in Atred#2 × Heller#1 and 16.3 to 56.6%, 6.7 to 15.7%, 4.1 to 10.1%, and 5.1 to 20.2% of the variation in the Atred#2 × Dunkler population. Only the resistance allele of QLr.cim-2BC was from the susceptible parent Atred#2, and resistance alleles at other loci came from the resistant parents Heller#1 and Dunkler. The SNP markers closely linked to Lr46 and QLr.cim-2BC were converted to kompetitive allele specific PCR markers for use in marker-assisted selection to improve leaf rust resistance through crosses with Heller#1 and Dunkler sources.

Genome-Wide Mapping of Adult Plant Resistance to Leaf Rust and Stripe Rust in CIMMYT Wheat Line Arableu#1.

Leaf (brown) rust (LR) and stripe (yellow) rust (YR), caused by Puccinia triticina and P. striiformis f. sp. tritici, respectively, significantly reduce wheat production worldwide. Disease-resistant wheat varieties offer farmers one of the most effective ways to manage these diseases. The common wheat (Triticum aestivum L.) Arableu#1, developed by the International Maize and Wheat Improvement Center and released as Deka in Ethiopia, shows susceptibility to both LR and YR at the seedling stage but a high level of adult plant resistance (APR) to the diseases in the field. We used 142 F5 recombinant inbred lines (RILs) derived from Apav#1 × Arableu#1 to identify quantitative trait loci (QTLs) for APR to LR and YR. A total of 4,298 genotyping-by-sequencing markers were used to construct a genetic linkage map. The study identified four LR resistance QTLs and six YR resistance QTLs in the population. Among these, QLr.cim-1BL.1/QYr.cim-1BL.1 was located in the same location as Lr46/Yr29, a known pleiotropic resistance gene. QLr.cim-1BL.2 and QYr.cim-1BL.2 were also located on wheat chromosome 1BL at 37 cM from Lr46/Yr29 and may represent a new segment for pleiotropic resistance to both rusts. QLr.cim-7BL is likely Lr68 given its association with the tightly linked molecular marker cs7BLNLRR. In addition, QLr.cim-3DS, QYr.cim-2AL, QYr.cim-4BL, QYr.cim-5AL, and QYr.cim-7DS are probably new resistance loci based on comparisons with published QTLs for resistance to LR and YR. Our results showed the diversity of minor resistance QTLs in Arableu#1 and their role in conferring near-immune levels of APR to both LR and YR, when combined with the pleiotropic APR gene Lr46/Yr29.

Aquaporin-4 mediates astrocyte response to ß-amyloid.

It has been demonstrated that the water channel protein aquaporin-4 (AQP4) plays an important role in astrocyte plasticity in response to a variety of injuries or stimuli. However, the potential role of AQP4 in astrocyte response to ß-amyloid (Aß) has not been studied. The purpose of this study was to investigate this issue. Compared to media control, the lower concentrations of Aß(1-42) (0.1-1 µM) increased AQP4 expression in cultured mouse cortical astrocytes, while the higher concentrations of Aß(1-42) (10 µM) decreased AQP4 expression. AQP4 gene knockout reduced Aß(1-42)-induced astrocyte activation and apoptosis, which was associated with a reduction in the uptake of Aß via decreased upregulation of low-density lipoprotein receptor related protein-1. Moreover, time-course and levels of Aß(1-42)-induced mitogen-activated protein kinase phosphorylation were altered in AQP4 null astrocytes compared with wild-type controls. Our data reveal a novel role of AQP4 in the uptake of Aß by astrocytes, indicating that AQP4 is a molecular target for Alzheimer's disease.

Stripe rust and leaf rust resistance in CIMMYT wheat line "Mucuy" is conferred by combinations of race-specific and adult-plant resistance loci.

Developing wheat varieties with durable resistance is a core objective of the International Maize and Wheat Improvement Center (CIMMYT) and many other breeding programs worldwide. The CIMMYT advanced wheat line "Mucuy" displayed high levels of resistance to stripe rust (YR) and leaf rust (LR) in field evaluations in Mexico and several other countries. To determine the genetic basis of YR and LR resistance, 138 F5 recombinant inbred lines (RILs) derived from the cross of Apav#1× Mucuy were phenotyped for YR responses from 2015 to 2020 at field sites in India, Kenya, and Mexico, and LR in Mexico. Seedling phenotyping for YR and LR responses was conducted in the greenhouse in Mexico using the same predominant races as in field trials. Using 12,681 polymorphic molecular markers from the DArT, SNP, and SSR genotyping platforms, we constructed genetic linkage maps and QTL analyses that detected seven YR and four LR resistance loci. Among these, a co-located YR/LR resistance loci was identified as Yr29/Lr46, and a seedling stripe rust resistance gene YrMu was mapped on the 2AS/2NS translocation. This fragment also conferred moderate adult plant resistance (APR) under all Mexican field environments and in one season in Kenya. Field trial phenotyping with Lr37-virulent Puccinia triticina races indicated the presence of an APR QTL accounting for 18.3-25.5% of the LR severity variation, in addition to a novel YR resistance QTL, QYr.cim-3DS, derived from Mucuy. We developed breeder-friendly KASP and indel molecular markers respectively for Yr29/Lr46 and YrMu. The current study validated the presence of known genes and identified new resistance loci, a QTL combination effect, and flanking markers to facilitate accelerated breeding for genetically complex, durable rust resistance.

A Chromosome-Level Genome Assembly of the Parasitic Wasp Chelonus formosanus Sonan 1932 (Hymenoptera: Braconidae).

Chelonus formosanus Sonan 1932 (Hymenoptera: Braconidae) is a wasp capable of parasitizing a variety of lepidopteran pests at the "egg-larval" stage which distributes throughout Taiwan, Guangdong, Zhejiang, and Hainan provinces of China. This wasp has been successfully used to control pests such as Spodoptera litura Fabricius, 1775, Spodoptera frugiperda (JE Smith, 1797), Spodoptera exigua (Hübner, 1808), and Helicoverpa armigera (Hübner, 1808). So far, there is only one genome assembled from the Chelonus genus [Chelonus insularis (Cresson, 1865)] and it is fragmented with 455 scaffolds. Here, we report a chromosome-level genome assembly of C. formosanus, which was sequenced using PacBio, Illumina, and Hi-C technologies. The long reads were 35.4 Gb (∼150× coverage) with an average length of 15.23 kb. The size of the genome assembly was 139.59 Mb. More than 99.46% of the assembled sequences were anchored to seven pseudochromosomes (138.84 Mb). The Benchmarking University Single-Copy Orthologs (BUSCO) assessment results showed 99.0% of the 1,367 genes (insect_odb10 database) were completely present. We annotated 11,242 protein-coding genes including 98.6% of BUSCO complete genes that were recovered. Nearly one-fourth of the genome assembly (22.25%) was annotated as repetitive sequences and 324 noncoding RNAs were predicted. There were 58 gene families found with significant expansion including allelopathic families (odorant receptors and ionotropic receptors), which may play a crucial role in efficiently locating a wide range of hosts. This high-quality genome assembly and annotation could provide a highly valuable resource of parasitic wasp for the biological control of Lepidoptera pest.

Tanshinone IIA derivatives induced S-phase arrest through stabilizing c-myc G-quadruplex DNA to regulate ROS-mediated PI3K/Akt/mTOR pathway.

Herein, a derivate from tanshinone IIA, 1,6,6-trimethyl-11-phenyl-7,8,9,10-tetrahydro-6H-furo[2',3':1,2]phenanthro[3,4-d]imidazole (TA25), has been synthesized and investigated as potential inhibitor against the proliferation, migration and invasion of lung cancer cells. MTT assay and cell colony formation assay results showed that TA25 exhibits acceptable inhibitory effect against the proliferation of lung cancer A549 cells, and the value of IC50 was about 17.9 µM. This result was further confirmed by the inhibition of TA25 against the growth of xenograft lung cancer cells on zebrafish bearing tumor (A549 lung cancer cells). The results of wound-healing assay and FITC-gelatin invasion assay displayed that TA25 could inhibit the migration and invasion of lung cancer A549 cells. Moreover, the studies on the binding properties of TA25 interact with c-myc G-quadruplex DNA suggested that TA25 can bind in the G-quarter plane formed from G7, G11, G16 and G20 with c-myc G-quadruplex DNA through π-π stacking. Further study of the potential anti-cancer mechanism indicated that TA25 can induce S-phase arrest in lung cancer A549 cells, and this phenomenon resulted from the promotion of the production of reactive oxygen species and DNA damage in A549 cells under the action of TA25. Further research revealed that TA25 could inhibit the PI3K/Akt/mTOR signal pathway and increase the expression of p53 protein. Overall, TA25 can be developed into a promising inhibitor against the proliferation, migration and invasion of lung cancer cells and has potential clinical application in the near future.

Effect of activated carbon fiber anode structure and electrolysis conditions on electrochemical degradation of dye wastewater.

The alizarin red S (ARS) in simulated dye wastewater was electrochemically oxidized using an activated carbon fiber (ACF) felt as an anode. The influence of electrolytic conditions and anode structure on the dye degradation was investigated. The results indicated that initial pH, current density and supporting electrolyte type all played an important role in the dye degradation. The chemical oxygen demand (COD) removal efficiency of dye solution in neutral or alkaline medium was about 74% after 60 min of electrolysis, which was higher than that in acidic medium. Increasing current density would lead to a corresponding increase in the dye removal. The addition of NaCl could also improve the treatment effect by enhancing the COD removal efficiency 10.3%. For ACF anodes, larger specific surface area and higher mesopore percentage could ensure more effective electrochemical degradation of dye. The data showed that the color removal efficiency increased from 54.2 to 83.9% with the specific surface area of ACF anodes increasing correspondingly from 894 to 1,682 m(2)/g.

[Burkholderia cepacia: our enemy or friend?].

It was briefly described the beneficial and harmful effects of Burkholderia cepacia in agriculture, industry, medical science and environment protection since the bacterium was identified as causal organism of a crop in 1949. The hot-points and problems in research and regulation of the bacterium were discussed and analyzed as well as the research suggestions in China.

The Histone Acetyltransferase Gcn5 Regulates ncRNA-ICR1 and FLO11 Expression during Pseudohyphal Development in Saccharomyces cerevisiae.

Filamentous growth is one of the key features of pathogenic fungi during the early infectious phase. The pseudohyphal development of yeast Saccharomyces cerevisiae shares similar characteristics with hyphae elongation in pathogenic fungi. The expression of FLO11 is essential for adhesive growth and filament formation in yeast and is governed by a multilayered transcriptional network. Here we discovered a role for the histone acetyltransferase general control nonderepressible 5 (Gcn5) in regulating FLO11-mediated pseudohyphal growth. The expression patterns of FLO11 were distinct in haploid and diploid yeast under amino acid starvation induced by 3-amino-1,2,4-triazole (3AT). In diploids, FLO11 expression was substantially induced at a very early stage of pseudohyphal development and decreased quickly, but in haploids, it was gradually induced. Furthermore, the transcription factor Gcn4 was recruited to the Sfl1-Flo8 toggle sites at the FLO11 promoter under 3AT treatment. Moreover, the histone acetylase activity of Gcn5 was required for FLO11 induction. Finally, Gcn5 functioned as a negative regulator of the noncoding RNA ICR1, which is known to suppress FLO11 expression. Gcn5 plays an important role in the regulatory network of FLO11 expression via Gcn4 by downregulating ICR1 expression, which derepresses FLO11 for promoting pseudohyphal development.

[Effect of Baisuifang Granule on cognitive malfunction after cerebral infarction].

OBJECTIVE: To explore the mechanism of Baisuifang Granule in treating cognitive malfunction after cerebral infarction. METHODS: One hundred and sixty patients with cerebral infarction were divided randomly into two groups. Eighty patients were treated with Baisuifang Granule and 80 with nimodipine for two months. Clinical observation and laboratory examinations were performed for Mini-Mental State Examination (MMSE), clinical symptoms, Chinese Stroke Scale (CSS), hemorrheological indexes and fibrinogen before and after the treatment. RESULTS: Baisuifang Granule could improve MMSE, reduce the scores of clinical symptoms and CSS, and meliorate the blood rheology. The total effective rate for clinical symptoms in the Baisuifang treated group accounted to 76.25%, with statistical difference comparing to 58.75% of nimodipine treated group (P<0.05). There was significant difference in symptom integral, CSS and whole blood viscosity at the high shear rate, respectively (P<0.01). CONCLUSION: Baisuifang Granule is an effective Chinese medicine for treating cognitive malfunction after cerebral infarction.

Dimethyl sulfoxide damages mitochondrial integrity and membrane potential in cultured astrocytes.

Dimethyl sulfoxide (DMSO) is a polar organic solvent that is used to dissolve neuroprotective or neurotoxic agents in neuroscience research. However, DMSO itself also has pharmacological and pathological effects on the nervous system. Astrocytes play a central role in maintaining brain homeostasis, but the effect and mechanism of DMSO on astrocytes has not been studied. The present study showed that exposure of astrocyte cultures to 1% DMSO for 24 h did not significantly affect cell survival, but decreased cell viability and glial glutamate transporter expression, and caused mitochondrial swelling, membrane potential impairment and reactive oxygen species production, and subsequent cytochrome c release and caspase-3 activation. DMSO at concentrations of 5% significantly inhibited cell variability and promoted apoptosis of astrocytes, accompanied with more severe mitochondrial damage. These results suggest that mitochondrial impairment is a primary event in DMSO-induced astrocyte toxicity. The potential cytotoxic effects on astrocytes need to be carefully considered during investigating neuroprotective or neurotoxic effects of hydrophobic agents dissolved by DMSO.