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Fusarium crown rot (FCR) is an important disease on wheat (Triticum aestivum L.) all over the world. Fusarium pseudograminearum is reported the main causal agent of FCR in China (Deng et al. 2020). In 2020, FCR occurred in wheat in Langfang, Hebei Province (116.31°E, 38.82°N) with observed incidence of 37.2% (48 out of 129 plants in total). The diseased wheat showed brown lesions at the crown and then stem necrosis. Samples with diseased symptom were collected from fields in late May 2020 (at the premature stage, 36 weeks after planting) (e-Xtra 1A). To perform fungal isolation, 0.3 cm2 samples excised at the symptomatic crown were surface disinfested with 75% ethanol for 10 s, and 0.1% HgCl2 for 40 s, then washed three times with sterile ddH2O. When cultured on potato dextrose agar (PDA), the colonies of two isolates out of Langfang (11.8% frequency) initially arewhite becoming violet with age, with violet pigments produced on PDA (e-Xtra 1B). Single-spored isolates were acquired, macroconidia were slender, thin walled, with 3- to 5-septate, measurements of 15.7-31.4 µm × 2.7-6.3 µm (n=50) (e-Xtra 1C). The pure culture were named as HWA94 and HWA97, respectively. DNA was extracted from the single-spored mycelium of HWA97 using the CTAB method (Leslie and Summerell, 2006). Internal transcribed spacer (ITS) region, partial sequences of actin (ACT), translation elongation factor 1-α (EF-1α) gene, 28S ribosomal RNA (LSU), and DNA-dependent RNA polymerase II largest subunit rpb1 (RPB1) were amplified using primers ITS1/ITS4, EF-1F/EF-1R, ACT512F/ACT728R, LR/LROR and RPB1B-F/ RPB1B-R and sequenced. The ITS, EF-1α, ACT, LSU, and RPB1 sequences were deposited in GenBank under accession numbers OM459813 to OM459817. These sequences showed 99.64%, 100%, 100%, 100%, and 100% similarity with the reference strain F. nygamai CBS749.97, respectively, resulting in HWA97 being identified as F. nygamai. To confirm the pathogenicity, inoculum was prepared by inoculating fully colonized F. nygamai (HWA97) PDA plugs on sterile wheat grain medium, cultured 7 days at 25â till massive mycelium formed, and hand shaken every two days to mix the wheat grains and the F. nygamai mycelium completely. Ten wheat seeds (cv. Jimai22, susceptible to FCR) for each 10-cm pot were inoculated with 10 g of inoculum when planting, then covered with soil. Mock inoculated wheat seeds with sterile grain without inoculum were used as control. The experiment was conducted in greenhouse, and repeated three times. Symptoms (brown necrosis at the crown) appeared 35 days after inoculation (dai) (e-Xtra 1D), with 91.5% incidence and 49.5±2.6 disease index. Mock-inoculated plants remained symptomless (e-Xtra 1E). Fusarium nygamai was re-isolated from the symptomatic stem and identified by morphological and molecular analysis, fulfilling Koch's postulates. Fusarium nygamai has been previously reported and recovered from wheat root and stalk (Fard et al. 2017) and causes root rot on wheat in Iraq (Minati, 2020), rice in Sardinia (Balmas et al. 2000), sugar beet in China (Cao et al. 2018), as well as lentil (Lens culinaris Medikus) in Pakistan (Rauf et al. 2016). To our knowledge, this is the first report of F. nygamai causing FCR of wheat in China. This study contributes useful information for epidemiologic studies for FCR. Additional studies will be needed to determine the distribution, aggressiveness, and impact on yield of F. nygamai compared with the dominant causal agent F. pseudograminearum.
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Photocatalytic CO2 reduction by solar energy into carbonaceous feedstock chemicals is recognized as one of the effective ways to mitigate both the energy crisis and greenhouse effect, which fundamentally relies on the development of advanced photocatalysts. Here, the exploration of porous microrod photocatalysts based on novel NiCoO solid solutions derived from bimetallic metal-organic frameworks (MOFs) is reported. They exhibit overall enhanced photocatalytic performance with both high activity and remarkable selectivity for reducing CO2 into CO under visible-light irradiation, which are superior to most related photocatalysts reported. Accordingly, the Ni0.2 -Co0.8 -O microrod (MR-N0.2 C0.8 O) photocatalyst delivers high efficiency for photocatalytic CO2 reduction into CO at a rate up to ≈277 µmol g-1 h-1 , which is ≈35 times to that of its NiO counterpart. Furthermore, they display a high selectivity of ≈85.12%, which is not only better than that of synthesized Co3 O4 (61.25%) but also superior to that of reported Co3 O4 -based photocatalysts. It is confirmed that the Co and Ni species are responsible for CO2 CO conversion activity and selectivity, respectively. In addition, it is verified, by adjusting the Ni contents, that the band structure of NiCoO microrods can be tailored with favorable reduction band potentials, which thus enhance the selectivity toward CO2 photoreduction.
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China is the largest chili pepper producing country, and Hebei Province stands out as the forth with planting area at about 1500 km2 in China. Pepper (Capsicum annuum L.) is susceptible to Colletotrichum spp. infection during its growth, which seriously affects production yield and quality. In September 2020, widespread anthracnose was observed on pepper in Hebei (115.48° N, 38.77° E), China. Necrotic lesions on pepper fruits were suborbcular, sunken, with acervuli arranged in the middle of lesion (e-Xtra 1A). To perform fungal isolation, small tissue with 0.3 cm2 in size at the symptomatic tissue margin was surface disinfested with 75% ethanol for 10 s, and 0.1% HgCl2 for 40 s, then washed three times with sterile ddH2O. Fragments were placed on potato dextrose agar (PDA) amended with 100 mg·L-1 chloramphenicol and incubated at 28 ºC under darkness for 4 days. One of the strains of Colletotrichum spp., named HQY157, was purified by single-spore isolation, then used for morphological characterization, phylogenetic analysis, and pathogenicity tests. Colonies presented light grey aerial mycelium, occasionally mixed with gray-black strips, and the reverse was similar to the surface on PDA (e-Xtra 1B). Conidia were smooth-walled, aseptate, straight with obtuse to slightly rounded ends, 17.3-28.5 × 3.1-7.4 µm (n=50) (e-Xtra 1C). For molecular identification, the internal transcribed spacer (ITS) region, partial sequences of actin (ACT), ß-tublin (TUB), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and chitin synthase (CHS) were sequenced using the specific primers (Weir et al. 2012). Sequences were deposited in GenBank with the following accession numbers OM317600-OM317604. A Maximum-Likelihood phylogenetic tree was constructed, based on the concatenated sequences (ACT, CHS, GAPDH, TUB, and ITS) of HQY157 and other closely matching Colletotrichum species obtained from GenBank, by using MEGA-X. It showed that HQY157 was grouped with the C. sojae with bootstrap values of 100% (e-Xtra 2). To confirm the pathogenicity, surface-sterilized healthy pepper fruits and healthy fruits with wounds (deal with a sterile toothpick after surface-sterilized) were then inoculated with 2 µL of conidial suspension (106 conidia/mL). The fruits inoculated with 2 µL sterile distilled water were taken as negative controls. After inoculation, the fruits were kept in a plastic box with sterilized filter paper moistened with sterilized water, and maintained at 25°C in the dark. The experiment was repeated three times. Anthracnose symptoms were observed 7 days after inoculation on the wounded pepper fruits, whereas the unwounded and negative control fruits remained symptomless (e-Xtra 1D). Colletotrichum sojae was re-isolated from the infected pepper fruits and identified by morphological and molecular analysis, fulfilling Koch's postulates. Colletotrichum sojae occurs mainly on Fabaceae plants such as Glycine max, Medicago sativa, Phaseolus vulgaris, and Vigna unguiculata (Damm et al. 2019, Talhinhas and Baroncelli, 2021), and Panax quinquefolium (Guan et al. 2021). To our knowledge, this is the first report of C. sojae causing anthracnose on pepper in China. This study provided crucial information for epidemiologic studies and appropriate control strategies for this chili pepper disease.
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Since the possible roles of surface modifications in determining multi-walled carbon nanotube (MWCNT)-promoted endoplasmic reticulum (ER) stress-mediated lipid-laden macrophage foam cell formation are still in debate, we compared unmodified and carboxylated MWCNT-induced cytotoxicity, lipid profile changes, and expression of ER stress genes in THP-1 macrophages. Particularly, we focused on lipid profile changes by using lipidomics approaches. We found that unmodified and carboxylated MWCNTs significantly decreased cellular viability and appeared to damage the cellular membrane to a similar extent. Likewise, the results from Oil Red O staining showed that both types of MWCNTs slightly but significantly induced lipid accumulation. In keeping with Oil Red O staining results, lipidomics data showed that both types of MWCNTs up-regulated most of the lipid classes. Interestingly, almost all lipid classes were relatively higher in carboxylated MWCNT-exposed THP-1 macrophages compared with unmodified MWCNT-exposed cells, indicating that carboxylated MWCNTs more effectively changed lipid profiles. But in contrast to our expectation, none of the MWCNTs significantly induced the expression of ER stress genes. Even, compared with carboxylated MWCNTs, unmodified MWCNTs induced higher expression of lipid genes, including macrophage scavenger receptor 1 and fatty acid synthase. Combined, our results suggested that even though carboxylation did not significantly affect MWCNT-induced lipid accumulation, carboxylated MWCNTs were more potent to alter lipid profiles in THP-1 macrophages, indicating the need to use omics techniques to understand the exact nanotoxicological effects of MWCNTs. However, the differential effects of unmodified and carboxylated MWCNTs on lipid profiles might not be related with the induction of ER stress.
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Nanotubos de Carbono , Estresse do Retículo Endoplasmático , Lipidômica , Lipídeos , Macrófagos , Nanotubos de Carbono/toxicidadeRESUMO
NAC (NAM, AFAT1/2, and CUC2) transcription factors play important roles in plant growth and in resistance to abiotic and biotic stresses. Here, we show that the TaNAC35 gene negatively regulates leaf rust resistance in the wheat line Thatcher + Lr14b (TcLr14b) when challenged with a virulent isolate of Puccinia triticina (Pt). The TaNAC35 gene was cloned from this line, and blastp results showed that its open reading frame (ORF) was 96.16% identical to the NAC35-like sequence reported from Aegilops tauschii, and that it encoded a protein with 387 amino acids (aa) including a conserved NAM domain with 145 aa at the N-terminal alongside the transcriptional activation domain with 220 aa in the C-terminal. Yeast-one-hybrid analysis proved that the C-terminal of the TaNAC35 protein was responsible for transcriptional activation. A 250-bp fragment from the 3'-end of this target gene was introduced to a BSMV-VIGS vector and used to infect the wheat line Thatcher + Lr14b (TcLr14b). The BSMV-VIGS/TaNAC35-infected plant material showed enhanced resistance (infection type "1") to Pt pathotype THTT, which was fully virulent (infection type "4") on BSMV-VIGS only infected TcLr14b plants. Histological studies showed that inhibition of TaNAC35 reduced the formation of haustorial mother cells (HMC) and mycelial growth, implying that the TaNAC35 gene plays a negative role in the response of TcLr14b to Pt pathotype THTT. These results provide molecular insight into the interaction between Pt and its wheat host, and identify a potential target for engineering resistance in wheat to this damaging pathogen.
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Resistência à Doença , Puccinia/patogenicidade , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Triticum/microbiologia , Sequência de Aminoácidos , Clonagem Molecular , Interações Hospedeiro-Patógeno , Filogenia , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Folhas de Planta/genética , Folhas de Planta/microbiologia , Proteínas de Plantas/química , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Domínios Proteicos , Fatores de Transcrição/química , Ativação Transcricional , Triticum/genéticaRESUMO
OBJECTIVE: The study was primarily used to evaluate subchronic oral toxicity of rhubarb extract. METHODS: The rhubarb extract was orally administered to rats at doses of 0.00, 0.65, 1.62 and 4.05 g/kg BW/day for 13 weeks with a recovery period of 4 weeks. The weight and the relative organ weight of the kidney in the 0.65 g/kg BW group were significantly increased but no significant changes were seen in renal histopathology. When the rats received rhubarb extract at 1.62 g/kg BW or above, the relative weight of the spleen and kidney were significantly increased; the kidney was also swollen and black with hydronephrosis. Histologic examination showed that there was an obvious increase in pigment deposition in renal tubular epithelial cells. No toxic related changes were observed in the 0.65 g/kg BW group, even though organ weight was increased and relative ratio to body weight of kidney were observed at 0.65 g/kg BW dosage, no significant renal histopathologic changes were detected at this dose. Based on the current study conditions and results, the no observed adverse effect level (NOAEL) of rhubarb extract in rats is 0.65 g/kg BW/day.
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Extratos Vegetais/toxicidade , Rheum/toxicidade , Animais , Rim , Nível de Efeito Adverso não Observado , Tamanho do Órgão , Ratos , Ratos Sprague-Dawley , Testes de Toxicidade SubcrônicaRESUMO
Wheat (Triticum aestivum) common root rot (CRR) caused by predominant fungal pathogen Bipolaris sorokiniana occurs in all wheat-growing regions worldwide and is difficult to control. In this study, the efficacy of eight fungicides against Bipolaris sorokiniana was examined in in vitro assays, and we determined that the combined application of two fungicides significantly inhibits the growth of fungal mycelium. Half of the maximal effective concentration of a mixture containing fludioxonil and difenoconazole in the ratio 1:4 was 0.0372 mg/liter, and the cotoxicity coefficient was 160.14. Under an environmentally controlled pot assay, seed treatment with the mixture of fludioxonil and difenoconazole in the 1:4 ratio demonstrated the best control efficiency at seedling and adult stages, respectively. The best synergistic mixture on seed treatment was assessed in a 2-year field experiment at Hebei, China. The best control efficacy achieved at the seedling and adult stages was 82.65% and 68.48%, respectively. Overall, the in vitro mycelial growth inhibition assay and controlled-environment and field studies indicated that the synergistic action of a mixture of fludioxonil and difenoconazole provides effective control against wheat CRR. These findings highlight the potential application of the fungicide combination for controlling CRR and reducing the selection pressure on fungal pathogens by lessening the use of various fungicides in the field.
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Fungicidas Industriais , Triticum , Bipolaris , China , Fungicidas Industriais/farmacologia , Doenças das PlantasRESUMO
BACKGROUND: Wheat leaf rust is an important disease worldwide. Understanding the pathogenic molecular mechanism of Puccinia triticina Eriks. (Pt) and the inconstant toxic region is critical for managing the disease. The present study aimed to analyze the pathogenic divergence between Pt isolates. RESULTS: Total RNA was extracted from the wheat cultivar Thatcher infected by two Pt isolates, Tc361_1 (THTT) and Tc284_2 (THTS), at 144 h post inoculation (hpi). The mRNA was then sequenced, and a total of 2784 differentially expressed genes (DEGs) were detected. Forty-five genes were specifically expressed in THTT; these genes included transcription initiation factors and genes with transmembrane transporter activity and other genes. Twenty-six genes were specifically expressed in THTS, including genes with GTPase activity, ABC transporters and other genes. Fifty-four differentially expressed candidate effectors were screened from the two isolates. Two candidate effectors were chosen and validated on tobacco, and the results showed that they could inhibit necrosis induced by BAX. qRT-PCR of 12 significant DEGs was carried out to validate that the results are similar to those of RNA-seq at 144 hpi, to show the expression levels of these DEGs in the early stage and to elucidate the differences in expression between the two Pt pathotypes. CONCLUSION: The results obtained in this study showed that although the two pathotypes of THTT and THTS contribute similar virulence to wheat, there are a large number of genes participate in the interaction with the susceptible wheat cultivar Thatcher, and revealed the pathogenicity of rust is very complicated.
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Doenças das Plantas/microbiologia , Puccinia/genética , Puccinia/patogenicidade , Triticum/microbiologia , Virulência , Resistência à Doença/genética , Interações Hospedeiro-Patógeno/genética , Doenças das Plantas/genética , RNA-Seq , Transcriptoma , Triticum/genéticaRESUMO
Wheat leaf rust, caused by Puccinia triticina, is a common fungal disease of wheat in China. In order to identify races and determine the individual virulence of isolates in different wheat-growing regions in China, leaf rust samples collected from 18 provinces in 2011 to 2013 were tested on 37 Thatcher near-isogenic lines each carrying a different single leaf rust resistance gene. A total of 158 races were identified. Races THTT (19.5%), THTS (16.9%), PHTT (7.7%), THJS (5.0%), THJT (4.2%), and PHTS (4.0%) were the most predominant races in 2011 to 2013. All of these races were avirulent to resistance genes Lr9 and Lr24. The two most frequent races, THTT and THTS, were widely distributed. The frequencies of the isolates with virulence to Lr1, Lr2c, Lr3, Lr16, Lr26, Lr17, LrB, Lr10, Lr14a, Lr3bg, Lr14b, Lr33, Lr37, and Lr50 exceeded 90%. Frequencies of virulence to Lr2a, Lr3ka, Lr11, Lr30, Lr2b, and Lr32 exceeded 70% but were less than 90%. Frequencies of virulence to Lr18, Lr21, Lr15, Lr23, Lr33+34, Lr36, Lr39, and Lr44 were below 70%, whereas the frequency of virulence to Lr25 was less than 1%. All isolates were avirulent to Lr9, Lr19, Lr24, Lr28, Lr42, Lr29, Lr38, and Lr47. The identified races and individual virulence frequencies provide a basis for selection of effective leaf rust resistance genes for use in breeding programs and can also provide information for the study of race evolution of P. triticina.
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Basidiomycota , Doenças das Plantas , China , Triticum , VirulênciaRESUMO
This study evaluated the subchronic toxicity of cerium nitrate and determined the no observed adverse effect level (NOAEL) in Wistar rats. In accordance with the Organization for Economic Co-operation and Development guidelines, cerium nitrate was orally administered to Wistar rats by gavage at 0, 0.2, 75, 150, and 300â¯mg/kgâ¯bw/day for 90 days, followed by 28 days of recovery period in the 300â¯mg/kgâ¯bw/day and the control groups. The following parameters were evaluated: mortality, abnormalities, body weight, food consumption, hematology, serum biochemistry, urinanalysis, gross necropsy and histopathology. At the end of the treatment, several significant changes were observed in the 300â¯mg/kgâ¯bw/day groups: relatively decreased mean body weight of males, increased LYMPH%, RET% and decreased NEUT%, RBC of the females, increased ALT, AST and decreased ALB, T-Bil, CHO, CK, LDH of males. Significantly decreased T-Bil, CHO, CK and LDH were also observed in males of the 150â¯mg/kgâ¯bw/day group. Pathological examination revealed that the incidences of foreign body granulomatous lesions in lungs were higher in the 150 and 300â¯mg/kgâ¯bw/day groups as compared with the control group. These findings were attributed to unexpected gavage exposure because the granuloma exhibited a bronchiole-derived distribution. Taken together, the NOAEL of cerium nitrate in Wistar rats is set to be 75â¯mg/kgâ¯bw/day in the present study.
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Cério/toxicidade , Administração Oral , Animais , Peso Corporal/efeitos dos fármacos , Contagem de Células , Feminino , Pulmão/efeitos dos fármacos , Pulmão/patologia , Masculino , Nível de Efeito Adverso não Observado , Ratos Wistar , Testes de Toxicidade SubcrônicaRESUMO
Haustoria, one of the fundamental characteristics of obligate parasite, is a micro-branch produced by biotrophic fungi and oomycetes, which is composed of haustorial body, extrahaustorial matrix and extrahaustorial membrane. It is an abnormal structure that can invade the host cell interaction with the plant. Haustoria is not only the key factor of biotrophic fungi carrying on the living specimen nutrition way but also represents significant roles in the nutrition biosynthesis and inhibiting the defense reaction of host. The deeper understanding of haustoria will favor us acquaint obligate parasite enormously, so that we can control the corresponding diseases better. This paper summarized the function on nutrition and pathogenicity of haustoria, and the problems and the research trend in this area were discussed.
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Fungos/fisiologia , Oomicetos/fisiologia , Organelas/fisiologia , Doenças das Plantas/microbiologia , Fungos/genética , Interações Hospedeiro-Patógeno , Oomicetos/genética , Organelas/genéticaRESUMO
Objective: The aim of these studies was to ascertain if Camelina sativa oil is harmful in both the acute and subchronic states. Methods: Wistar rats of both sexes were used in an acute toxicity test, and the fatal dosage (LD50) of oral Camelina sativa oil was greater than 27.6 g/kg bw. Rats were gavaged with Camelina sativa oil at dosages of 0.00, 0.92, 1.84, and 3.68 g/kg bw per day for 90 days. In addition, satellite groups were established in the control and high-dose groups for a 28-day recovery period. The following factors were assessed: mortality, clinical anomalies, body weight, food intake, hematological, serum biochemistry, urine, gross necropsy, and histology. Results: There were no observable toxicity-related changes in any of the three dosage groups. There is no toxicological relevance to the change in the high-dose hematological indicator PLT at the conclusion of the recovery period because it was within the usual range for this strain in our laboratory. The test material did not result in any pathological alterations, according to a pathological examination. Conclusion: Since the results of the current study, the no-observed-adverse-effect-level (NOAEL) for Camelina sativa oil in rats has been determined to be greater than 3.68 g/kg bw.
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The inflammation and fibrosis induced by silica dust are considered to be substantial responses in silicosis progression. Interleukin-1 beta (IL-1ß) plays an important role in silica-induced lung inflammation, but the mechanisms that underlie the influence of IL-1ß on the progression of silicosis remain unclear. In this study, the role of IL-1ß in silica-induced inflammation and fibrosis was evaluated by administering a suspension of 2.5-mg silica dust, either with or without 40 µg anti-mouse IL-1ß monoclonal antibody (mAb), to the lungs of male C57BL/6 mice. Silica + anti-IL-1ß mAb-treated mice showed the depletion of IL-1ß as well as the attenuation of inflammation, as evaluated in the bronchoalveolar lavage fluid (BALF) and histological sections from 1 to 84 days after silica exposure. Further study of the BALF indicated that inhibition of IL-1ß could reduce the contents of tumor necrosis factor-alpha and monocyte chemoattractant protein-1. The real-time PCR and pathology results showed that the neutralization of IL-1ß attenuated silica-induced fibrosis by inhibiting the gene expression of transforming growth factor-beta 1, collagen I and fibronectin. The examination of Th1-cytokine and Th2-cytokine suggested that depletion of IL-1ß decelerated the Th1/Th2 balance toward a Th2-dominant response. In conclusion, the present study suggests that the neutralization of IL-1ß attenuates silica-induced inflammation and fibrosis by inhibiting other inflammatory and fibrogenic mediators and modulating the Th1/Th2 balance.
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Interleucina-1beta/antagonistas & inibidores , Fibrose Pulmonar/tratamento farmacológico , Dióxido de Silício/toxicidade , Silicose/tratamento farmacológico , Animais , Anticorpos Bloqueadores/farmacologia , Anticorpos Monoclonais/farmacologia , Líquido da Lavagem Broncoalveolar/citologia , Contagem de Células , Colágeno Tipo I/biossíntese , Fibronectinas/biossíntese , Técnicas In Vitro , Pulmão/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Alvéolos Pulmonares/patologia , Fibrose Pulmonar/patologia , Silicose/patologia , Equilíbrio Th1-Th2/efeitos dos fármacos , Fator de Crescimento Transformador beta/biossínteseRESUMO
Fusarium crown rot (FCR) on wheat is a soil-borne disease that affects the yield and quality of the produce. In 2020, 297 Fusarium pseudograminearum isolates were isolated from diseased FCR wheat samples from eight regional areas across Hebei Province in China. Baseline sensitivity of F. pseudograminearum to fludioxonil (0.0613 ± 0.0347 µg/mL) and tebuconazole (0.2328 ± 0.0840 µg/mL) were constructed based on the in vitro tests of 71 and 83 isolates, respectively. The resistance index analysis showed no resistance isolate to fludioxonil but two low-resistance isolates to tebuconazole in 2020. There was an increased frequency of resistant isolates from 2021 to 2022 based on the baseline sensitivity for tebuconazole. There was no cross-resistance between fludioxonil and tebuconazole. This study provides a significant theoretical and practical basis for monitoring the resistance of F. pseudograminearum to fungicides, especially the control of FCR.
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Fungicidas Industriais , Fusarium , Triticum , Fungicidas Industriais/farmacologiaRESUMO
Chitin/polysaccharide deacetylases belong to the carbohydrate esterases family 4 (CE4 enzymes). They play a crucial role in modifying the physiochemical characteristics of structural polysaccharides and are also involved in a wide range of biological processes such as fungal autolysis, spore formation, cell wall formation and integrity, and germling adhesion. These enzymes are mostly common in fungi, marine bacteria, and a limited number of insects. They facilitate the deacetylation of chitin which is a structural biopolymer that is abundantly found in fungal cell walls and spores and also in the cuticle and peritrophic matrices of insects. The deacetylases exhibit specificity towards a substrate containing a sequence of four GlcNAc units, with one of these units being subjected to deacetylation. Chitin deacetylation results in the formation of chitosan, which is a poor substrate for host plant chitinases, therefore it can suppress the host immune response triggered by fungal pathogens and enhance pathogen virulence and colonization. This review discusses plant pathogenic fungal chitin/polysaccharide deacetylases including their structure, substrate specificity, biological roles and some recently discovered chitin deacetylase inhibitors that can help to mitigate plant fungal diseases. This review provides fundamental knowledge that will undoubtedly lead to the rational design of novel inhibitors that target pathogenic fungal chitin deacetylases, which will also aid in the management of plant diseases, thereby safeguarding global food security.
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Currently, two-dimensional/two-dimensional (2D/2D) van der Waals heterojunctions, as novel and excellent candidates for photocatalysts, have attracted significant attention because of their fundamentally improved interfacial charge separation/transfer and massive reactive centers. Herein, novel 2D/2D Ta3N5-nanosheet/ReS2-nanosheet van der Waals heterojunction photocatalysts are rationally designed through a method combining template-assisted and solution-adsorption processes. The resultant heterojunctions exhibit enhanced interfacial charge transfer, boosted light absorption and significantly increased reaction sites for hydrogen evolution. Correspondingly, they deliver a high photocatalytic hydrogen production activity of 615 µmol g-1 h-1, which is â¼3 and â¼12 times greater than that of bare Ta3N5 nanosheets and ReS2 nanosheets, respectively, and superior to those in the most recent reports about photocatalytic water splitting on Ta3N5 material, implying their potential applications as advanced catalysts for hydrogen evolution.
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To evaluate the reproductive toxicity of gene modified rice generated by introducing phytoene synthase (Psy) and bacterial phytoene desaturase (CrtI) from maize and Erwinia uredovora, Wistar rats were allocated into 3 groups and fed with Psy and CrtI gene modified rice mixture diet (GM group), non-gene modified rice mixture diet (non-GM group), and AIN-93 diet (Blank control group) from parental generation (F0) to the offsprings (F1). GM rice, Heijinmi (HJM) and Non-GM rice, Heishuai (HS), were both formulated into diets at ratios of 73.5% and 75.5% according to the AIN93 diet for rodent animals, respectively. Relative to the non-GM group, no biologically relevant differences were observed in GM group rats concerning reproductive performance such as fertility rate, gestation rate, mean duration, hormone level, and reproductive organ pathology. The developmental parameters results were not significantly different from the non-GM group such as body weight, food consumption, developmental neurotoxicity, behavior, hematology, and serum chemistry. In terms of immunotoxicity, the IgG indicators of offspring from the GM group improved in contrast with the non-GM group. Additional gut flora analysis of F0 generation rats resulted as that the treatment elicited an increased gut microflora diversity of F0 rats. And no horizontal gene transfer of Psy and CrtI genes in rats fed a GM rice HJM diet. In conclusion, we found no adverse effects related to GM rice in the extended one-generation reproductive toxicity study, indicating that GM rice is a safe alternative for its counterpart rice regarding reproductive toxicity.
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Microbioma Gastrointestinal , beta Caroteno , Ratos , Animais , Ratos Wistar , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/efeitos adversos , ReproduçãoRESUMO
Recently, extensive studies have focused on analyzing aerodynamic performance due to its important impact on aircraft design. Most of these works compute the aerodynamic coefficient of the airfoil through computational fluid dynamics (CFD) simulation, which is too time-consuming. To reduce the computational time required, some intelligence-based methods have been presented. However, these methods also suffer from certain issues. First, most of them directly implement existing machine learning methods used to predict the aerodynamic coefficient without adding any improvements. Second, some methods convert the airfoil shape and aerodynamic curves into images, which may lead to curve distortion and the introduction of noise. Third, some methods learn the relationship between the airfoil shape and aerodynamic coefficients but ignore the influence of initial inflow conditions. Accordingly, to address these issues, we propose an intelligent method for predicting the pressure coefficients (Cp) of airfoil based on a conditional generative adversarial network (cGAN). More specifically, we first present a two-step data augmentation strategy designed to expand the original airfoil dataset. Subsequently, we design a novel cGAN-based neural network to predict the Cp curve. To the best of our knowledge, this is the first work to apply generative adversarial network (GAN) to aerodynamic coefficient prediction. Moreover, we design a new loss function to train our network. Extensive experimental results demonstrate that the Cp curve predicted by our method is very close to that generated via CFD simulation. More importantly, our method achieves a speedup close to 1000x compared with CFD simulation.
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Aprendizado de Máquina , Redes Neurais de Computação , Simulação por ComputadorRESUMO
Wheat leaf rust, caused by the obligate biotrophic fungus Puccinia triticina Eriks. (Pt), is one of the most common wheat foliar diseases that continuously threatens global wheat production. Currently, the approaches used to mitigate pathogen infestation include the application of fungicides and the deployment of resistance genes or cultivars. However, the continuous deployment of selected resistant varieties causes host selection pressures that drive Pt evolution and promote the incessant emergence of new virulent races, resulting in the demise of wheat-resistant cultivars after several years of planting. Intriguingly, diploid wheat accessions were found to confer haustorium formation-based resistance to leaf rust, which involves prehaustorial and posthaustorial resistance mechanisms. The prehaustorial resistance in the interaction between einkorn and wheat leaf rust is not influenced by specific races of the pathogen. The induced defense mechanism, known as systemic acquired resistance, also confers durable resistance against a wide array of pathogens. This review summarizes the host range, pathogenic profile, and evolutionary basis of Pt; the molecular basis underlying wheat-Pt interactions; the cloning and characterization of wheat leaf rust resistance genes; prehaustorial and posthaustorial resistance; systemic acquired resistance; and the role of reactive oxygen species. The interplay between climatic factors, genetic features, planting dates, and disease dynamics in imparting resistance is also discussed.
RESUMO
Wheat powdery mildew caused by a biotrophic fungus Blumeria graminis f. sp. tritici (Bgt), is a widespread airborne disease which continues to threaten global wheat production. One of the most chemical-free and cost-effective approaches for the management of wheat powdery mildew is the exploitation of resistant cultivars. Accumulating evidence has reported that more than 100 powdery mildew resistance genes or alleles mapping to 63 different loci (Pm1-Pm68) have been identified from common wheat and its wild relatives, and only a few of them have been cloned so far. However, continuous emergence of new pathogen races with novel degrees of virulence renders wheat resistance genes ineffective. An essential breeding strategy for achieving more durable resistance is the pyramiding of resistance genes into a single genotype. The genetics of host-pathogen interactions integrated with temperature conditions and the interaction between resistance genes and their corresponding pathogen a virulence genes or other resistance genes within the wheat genome determine the expression of resistance genes. Considerable progress has been made in revealing Bgt pathogenesis mechanisms, identification of resistance genes and breeding of wheat powdery mildew resistant cultivars. A detailed understanding of the molecular interactions between wheat and Bgt will facilitate the development of novel and effective approaches for controlling powdery mildew. This review gives a succinct overview of the molecular basis of interactions between wheat and Bgt, and wheat defense mechanisms against Bgt infection. It will also unleash the unsung roles of epigenetic processes, autophagy and silicon in wheat resistance to Bgt.