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The interactions among plant viruses, insect vectors, and host plants have been well studied; however, the roles of insect viruses in this system have largely been neglected. We investigated the effects of MpnDV infection on aphid and PVY transmission using bioassays, RNA interference (RNAi), and GC-MS methods and green peach aphid (Myzus persicae (Sulzer)), potato virus Y (PVY), and densovirus (Myzus persicae nicotianae densovirus, MpnDV) as model systems. MpnDV increased the activities of its host, promoting population dispersal and leading to significant proliferation in tobacco plants by significantly enhancing the titer of the sesquiterpene (E)-ß-farnesene (EßF) via up-regulation of expression levels of the MpFPPS1 gene. The proliferation and dispersal of MpnDV-positive individuals were faster than that of MpnDV-negative individuals in PVY-infected tobacco plants, which promoted the transmission of PVY. These results combined showed that an insect virus may facilitate the transmission of a plant virus by enhancing the locomotor activity and population proliferation of insect vectors. These findings provide novel opportunities for controlling insect vectors and plant viruses, which can be used in the development of novel management strategies.
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Áfidos , Densovirus , Nicotiana , Enfermedades de las Plantas , Áfidos/virología , Áfidos/fisiología , Animales , Nicotiana/virología , Nicotiana/parasitología , Enfermedades de las Plantas/virología , Densovirus/fisiología , Densovirus/genética , Potyvirus/fisiología , Potyvirus/patogenicidad , Sesquiterpenos/metabolismo , Virus de Plantas/fisiología , Virus de Plantas/patogenicidadRESUMEN
Skeletal muscle is the mainly edible part of fish. Eicosapentaenoic acid (EPA) is a crucial nutrient for fish. This study investigated the effect of EPA on the muscle development of grass carp along with the potential molecular mechanisms in vivo and in vitro. Muscle cells treated with 50 µM EPA in vitro showed the elevated proliferation, and the expression of mammalian target of rapamycin (mTOR) signaling pathway-related genes was upregulated (P < 0.05). In vivo experiments, 270 grass carp (27.92 g) were fed with one of the three experimental diets for 56 days: control diet (CN), 0.3% EPA-supplement diet (EPA), and the diet supplemented with 0.3% EPA and 30 mg/kg rapamycin (EPA + Rap). Fish weight gain rate (WGR) was improved in EPA group (P < 0.05). There was no difference in the viscerosomatic index (VSI) and body height (BH) among all groups (P > 0.05), whereas the carcass ratio (CR) and body length in the EPA group were obviously higher than those of other groups (P < 0.05), indicating that the increase of WGR was due to muscle growth. In addition, both muscle fiber density and muscle crude protein also increased in EPA group (P < 0.05). The principal component analysis showed that total weight of muscle amino acid in EPA group ranked first. Dietary EPA also increased protein levels of the total mTOR, S6k1, Myhc, Myog, and Myod in muscle (P < 0.05). In conclusion, EPA promoted the muscle development and nutritive value via activating the mTOR signaling pathway.
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Carpas , Ácido Eicosapentaenoico , Animales , Ácido Eicosapentaenoico/farmacología , Ácido Eicosapentaenoico/análisis , Carpas/metabolismo , Transducción de Señal , Dieta , Músculo Esquelético/metabolismo , Proteínas en la Dieta , Serina-Treonina Quinasas TOR/genética , Serina-Treonina Quinasas TOR/metabolismo , Desarrollo de Músculos , Valor Nutritivo , Alimentación Animal/análisis , Proteínas de Peces/genética , Mamíferos/metabolismoRESUMEN
Herbivore-induced plant volatiles (HIPVs) are known to be perceived by neighboring plants, resulting in induction or priming of chemical defenses. There is little information on the defense responses that are triggered by these plant-plant interactions, and the phenomenon has rarely been studied in rice. Using chemical and molecular analyses in combination with insect behavioral and performance experiments, we studied how volatiles emitted by rice plants infested by the striped stemborer (SSB) Chilo suppressalis affect defenses against this pest in conspecific plants. Compared with rice plants exposed to the volatiles from uninfested plants, plants exposed to SSB-induced volatiles showed enhanced direct and indirect resistance to SSB. When subjected to caterpillar damage, the HIPV-exposed plants showed increased expression of jasmonic acid (JA) signaling genes, resulting in JA accumulation and higher levels of defensive proteinase inhibitors. Moreover, plants exposed to SSB-induced volatiles emitted larger amounts of inducible volatiles and were more attractive to the parasitoid Cotesia chilonis. By unraveling the factors involved in HIPV-mediated defense priming in rice, we reveal a key defensive role for proteinase inhibitors. These findings pave the way for novel rice management strategies to enhance the plant's resistance to one of its most devastating pests.
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Mariposas Nocturnas , Oryza , Compuestos Orgánicos Volátiles , Animales , Oryza/genética , Plantas/metabolismo , Insectos/metabolismo , Herbivoria , Péptido Hidrolasas/metabolismo , Compuestos Orgánicos Volátiles/metabolismo , Ciclopentanos/metabolismoRESUMEN
BACKGROUND: A novel myeloperoxidase-activatable manganese-based (MPO-Mn) MRI probe may enable the activation state of inflammatory foci to be detected and monitored noninvasively. PURPOSE: To evaluate the inflammatory response in a mouse model of acute gout using MPO as an imaging biomarker and a potential therapeutic target. STUDY TYPE: Prospective. ANIMAL MODEL: A total of 40 male Swiss mice with monosodium urate crystals induced acute gout. FIELD STRENGTH/SEQUENCE: A 3.0 T/T1-weighted imaging with 2D fast spoiled gradient recalled echo and T2-weighted imaging with fast recovery fast spin-echo sequences. ASSESSMENT: The difference in contrast-to-noise ratio between left hind limb (lesion) and right hind limb (internal reference) (ΔCNR), and normalized signal-to-noise ratio (nSNR) on the right hind limb were calculated and compared. The expression level and activity of myeloperoxidase (MPO) were analyzed using western blotting and spectrophotometric quantitation activity assay. MPO-positive cell infiltration and lesion volume were evaluated using immunofluorescence staining and T2-weighted images, respectively. STATISTICAL TESTS: Student's t test. A P-value less than 0.05 was considered to be statistically significant. RESULTS: MPO-Mn resulted in a significantly higher ΔCNR than Gd-DTPA (22.54 ± 1.86 vs. 13.90 ± 2.22) but lower nSNR on the reference right hind limb (1.08 ± 0.07 vs. 1.21 ± 0.08). Compared to the nontreatment group, MPO-inhibition resulted in a significantly reduced contrast enhancement at the lesion (17.81 ± 1.58 vs. 22.96 ± 3.12), which was consistent with a remission of the inflammatory response, as evidenced by a substantial reduction of lesion volume (0.55 ± 0.16 mm3 /g vs. 1.14 ± 0.15 mm3 /g), myeloperoxidase expression level (0.98 ± 0.09 vs. 1.48 ± 0.19) and activity (0.75 ± 0.12 vs. 1.12 ± 0.07), and inflammatory cell recruitment. DATA CONCLUSION: MPO-Mn MRI has potential to evaluate the activation state of inflammatory foci in the experimental model of acute gout. EVIDENCE LEVEL: 1. TECHNICAL EFFICACY: Stage 1.
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Medios de Contraste , Gota , Masculino , Animales , Ratones , Peroxidasa/metabolismo , Estudios Prospectivos , Imagen por Resonancia Magnética/métodos , Gota/diagnóstico por imagenRESUMEN
"Shi Ying Zi" powder is a traditional Chinese herbal formula for preventing and treating coccidiosis. In our previous studies, it showed anticoccidial effects and exhibited the potential to control Eimeria tenella infection. In this research, we evaluated the antioxidation and immune effect of "Shi Ying Zi" powder and its effective active ingredient osthole on coccidiosis-infected broilers to explore the mechanism of its anticoccidial effect. We analyzed changes in the antioxidant index, the pathological changes in cecum, immune index of serum and composition of cecal flora. The results showed that the use of "Shi Ying Zi" powder and osthole alleviated the pathological changes in the cecum, spleen and bursa of Fabricius, upregulated the spleen and bursal weigh index. "Shi Ying Zi" powder of 10 g/kg effectively rocovered the contents of interleukins and immunoglobulin in serum. Osthole increased the proportion of Firmicutes, Actino-bacteria and Lactobacillus in the cecum. In summary, "Shi Ying Zi" powder and osthole have anticoccidial effects, and they also can active the immunity, antioxidant functions and upregulate the beneficial bacteria population in Eimeria tenella-infected broilers.
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Coccidiosis , Eimeria tenella , Enfermedades de las Aves de Corral , Animales , Antioxidantes/farmacología , Antioxidantes/uso terapéutico , Pollos , Polvos , Coccidiosis/tratamiento farmacológico , Coccidiosis/veterinaria , Bacterias , Enfermedades de las Aves de Corral/tratamiento farmacológico , Enfermedades de las Aves de Corral/prevención & control , Ciego/patologíaRESUMEN
BACKGROUND: Non-small cell lung cancer (NSCLC) is the most prevalent form of lung cancer globally, with average age of cancer patients becoming younger gradually. It is of significance to gain a comprehensive understanding of molecular mechanism underlying NSCLC. METHODS: Quantitative polymerase chain reaction (qPCR) and western blot were applied to measure RNA and protein levels separately. Functional assays and western blot were performed to determine the effects of miR-489-3p and USP48 on cell growth, migration and epithelial-mesenchymal transition (EMT) in NSCLC. TOP/FOP flash luciferase reporter assay was carried out to detect the activity of Wnt pathway. Besides, qPCR, RNA pulldown and luciferase reporter assays were conducted to probe into the target gene of miR-489-3p. Immunoprecipitation-western blot (IP-western blot) analysis was implemented to assess the effect of USP48 on the ubiquitination of ß-catenin. RESULTS: miR-489-3p hampers NSCLC cell proliferation, migration and EMT in vitro and NSCLC tumorigenesis and metastasis in vivo. Additionally, miR-489-3p inactivates Wnt/ß-catenin signaling pathway and regulates USP48 to inhibit the ubiquitination of ß-catenin. Moreover, USP48 propels the development of NSCLC cells. CONCLUSIONS: The current study demonstrated that miR-489-3p promotes the malignant progression of NSCLC cells via targeting USP48, which might offer a new perspective into NSCLC treatment.
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Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , MicroARNs , ARN Largo no Codificante , Proteasas Ubiquitina-Específicas , Vía de Señalización Wnt , beta Catenina , Carcinoma de Pulmón de Células no Pequeñas/metabolismo , Carcinoma de Pulmón de Células no Pequeñas/patología , Línea Celular Tumoral , Movimiento Celular/genética , Proliferación Celular/genética , Humanos , Luciferasas/genética , Luciferasas/metabolismo , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patología , MicroARNs/metabolismo , ARN Largo no Codificante/genética , Proteasas Ubiquitina-Específicas/genética , Proteasas Ubiquitina-Específicas/metabolismo , beta Catenina/genética , beta Catenina/metabolismoRESUMEN
Chilo suppressalis is a major target pest of transgenic rice expressing the Bacillus thuringiensis (Bt) Cry1C toxin in China. The evolution of resistance of this pest is a major threat to Bt rice. Since Bt functions by binding to receptors in the midgut (MG) of target insects, identification of Bt functional receptors in C. suppressalis is crucial for evaluating potential resistance mechanisms and developing effective management strategies. ATP-binding cassette (ABC) transporters have been vastly reported to interact with Cry1A toxins, as receptors and their mutations cause insect Bt resistance. However, the role of ABC transporters in Cry1C resistance to C. suppressalis remains unknown. Here, we measured CsABCC2 expression in C. suppressalis Cry1C-resistant (Cry1C-R) and Cry1C-susceptible strains (selected in the laboratory) via quantitative real-time PCR (qRT-PCR); the transcript level of CsABCC2 in the Cry1C-R strain was significantly lower than that in the Cry1C-susceptible strain. Furthermore, silencing CsABCC2 in C. suppressalis via RNA interference (RNAi) significantly decreased Cry1C susceptibility. Overall, CsABCC2 participates in Cry1C mode of action, and reduced expression of CsABCC2 is functionally associated with Cry1C resistance in C. suppressalis.
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Bacillus thuringiensis , Mariposas Nocturnas , Oryza , Animales , Bacillus thuringiensis/genética , Bacillus thuringiensis/metabolismo , Toxinas de Bacillus thuringiensis , Proteínas Bacterianas/metabolismo , Regulación hacia Abajo , Endotoxinas/genética , Endotoxinas/metabolismo , Endotoxinas/farmacología , Proteínas Hemolisinas/genética , Proteínas Hemolisinas/metabolismo , Proteínas Hemolisinas/farmacología , Larva/fisiología , Mariposas Nocturnas/metabolismo , Oryza/metabolismo , Plantas Modificadas Genéticamente/genética , Plantas Modificadas Genéticamente/metabolismoRESUMEN
The APETALA2/ethylene-responsive factor (AP2/ERF) has important roles in regulating developmental processes and hormone signaling transduction in plants. Pineapple demonstrates a special sensitivity to ethylene, and AP2/ERFs may contribute to this distinct sensitivity of pineapples to ethylene. However, little information is available on the AP2/ERF of pineapple. In this study, 97 AP2/ERF family members were identified from the pineapple genome. The AcAP2/ERF superfamily could be further divided into five subfamilies, and different subfamily existed functional divergence in multifarious biological processes. ERF and RAV subfamily genes might play important roles in the process of ethylene response of pineapple; ERF and DREB subfamily genes had particular functions in the floral organ development. This study is the first to provide detailed information on the features of AP2/ERFs in pineapple, provide new insights into the potential functional roles of the AP2/ERF superfamily members, and will facilitate a better understanding of the molecular mechanism of flower in pineapple.
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Ananas/genética , Flores/genética , Proteínas de Plantas/genética , Factores de Transcripción/genética , Ananas/crecimiento & desarrollo , Etilenos/metabolismo , Etilenos/farmacología , Flores/efectos de los fármacos , Flores/crecimiento & desarrollo , Regulación del Desarrollo de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Proteínas de Plantas/metabolismo , Factores de Transcripción/metabolismoRESUMEN
Single-atom alloys hold great promise for electrocatalytic nitrogen reduction reaction (NRR), while the comprehensive experimental/theoretical investigations of SAAs for the NRR are still missing. Herein, PdFe1 single-atom alloy metallene, in which the Fe single atoms are confined on a Pd metallene support, is first developed as an effective and robust NRR electrocatalyst, delivering exceptional NRR performance with an NH3 yield of 111.9â µg h-1 mg-1 , a Faradaic efficiency of 37.8 % at -0.2â V (RHE), as well as a long-term stability for 100â h electrolysis. In-depth mechanistic investigations by theoretical computations and operando X-ray absorption/Raman spectroscopy indentify Pd-coordinated Fe single atoms as active centers to enable efficient N2 activation via N2 -to-Fe σ-donation, reduced protonation energy barriers, suppressed hydrogen evolution and excellent thermodynamic stability, thus accounting for the high activity, selectivity and stability of PdFe1 for the NRR.
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Advancements in -omics techniques provide powerful tools to assess the potential effects in composition of a plant at the RNA, protein and metabolite levels. These technologies can thus be deployed to assess whether genetic engineering (GE) causes changes in plants that go beyond the changes introduced by conventional plant breeding. Here, we compare the extent of transcriptome and metabolome modification occurring in leaves of four GE rice lines expressing Bacillus thuringiensis genes developed by GE and seven rice lines developed by conventional cross-breeding. The results showed that both types of crop breeding methods can bring changes at transcriptomic and metabolic levels, but the differences were comparable between the two methods, and were less than those between conventional non-GE lines were. Metabolome profiling analysis found several new metabolites in GE rice lines when compared with the closest non-GE parental lines, but these compounds were also found in several of the conventionally bred rice lines. Functional analyses suggest that the differentially expressed genes and metabolites caused by both GE and conventional cross-breeding do not involve detrimental metabolic pathways. The study successfully employed RNA-sequencing and high-performance liquid chromatography mass spectrometry technology to assess the unintended changes in new rice varieties, and the results suggest that GE does not cause unintended effects that go beyond conventional cross-breeding in rice.
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Ingeniería Genética/métodos , Oryza/genética , Fitomejoramiento/métodos , Bacillus thuringiensis/genética , Ingeniería Genética/efectos adversos , Metabolómica , Plantas Modificadas Genéticamente/efectos adversos , Plantas Modificadas Genéticamente/genética , Transcriptoma/genéticaRESUMEN
With 20% of the world's population but just 7% of the arable land, China has invested heavily in crop biotechnology to increase agricultural productivity. We examine research on insect-resistant genetically engineered (IRGE) crops in China, including strategies to promote their sustainable use. IRGE cotton, rice, and corn lines have been developed and proven efficacious for controlling lepidopteran crop pests. Ecological impact studies have demonstrated conservation of natural enemies of crop pests and halo suppression of crop-pest populations on a local scale. Economic, social, and human health effects are largely positive and, in the case of Bt cotton, have proven sustainable over 20 years of commercial production. Wider adoption of IRGE crops in China is constrained by relatively limited innovation capacity, public misperception, and regulatory inaction, suggesting the need for further financial investment in innovation and greater scientific engagement with the public. The Chinese experience with Bt cotton might inform adoption of other Bt crops in China and other developing countries.
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Productos Agrícolas , Plantas Modificadas Genéticamente , Animales , Toxinas de Bacillus thuringiensis , Proteínas Bacterianas , Endotoxinas , Ingeniería Genética , Gossypium/genética , Proteínas Hemolisinas , InsectosRESUMEN
BACKGROUND: Clear cell renal cell carcinoma (ccRCC) is the most common subtype of renal cell carcinoma and accounts for cancer-related deaths. Survival rates are very low when the tumor is discovered in the late-stage. Thus, developing an efficient strategy to stratify patients by the stage of the cancer and inner mechanisms that drive the development and progression of cancers is critical in early prevention and treatment. RESULTS: In this study, we developed new strategies to extract important gene features and trained machine learning-based classifiers to predict stages of ccRCC samples. The novelty of our approach is that (i) We improved the feature preprocessing procedure by binning and coding, and increased the stability of data and robustness of the classification model. (ii) We proposed a joint gene selection algorithm by combining the Fast-Correlation-Based Filter (FCBF) search with the information value, the linear correlation coefficient, and variance inflation factor, and removed irrelevant/redundant features. Then the logistic regression-based feature selection method was used to determine influencing factors. (iii) Classification models were developed using machine learning algorithms. This method is evaluated on RNA expression value of clear cell renal cell carcinoma derived from The Cancer Genome Atlas (TCGA). The results showed that the result on the testing set (accuracy of 81.15% and AUC 0.86) outperformed state-of-the-art models (accuracy of 72.64% and AUC 0.81) and a gene set FJL-set was developed, which contained 23 genes, far less than 64. Furthermore, a gene function analysis was used to explore molecular mechanisms that might affect cancer development. CONCLUSIONS: The results suggested that our model can extract more prognostic information, and is worthy of further investigation and validation in order to understand the progression mechanism.
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Carcinoma de Células Renales/patología , Neoplasias Renales/patología , Aprendizaje Automático , Área Bajo la Curva , Carcinoma de Células Renales/genética , Femenino , Humanos , Neoplasias Renales/genética , Modelos Logísticos , Estadificación de Neoplasias , ARN/metabolismo , Curva ROCRESUMEN
The complete genomic sequence of a putative novel member of the family Secoviridae was determined by high-throughput sequencing of a pineapple accession obtained from the National Plant Germplasm Repository in Hilo, Hawaii. The predicted genome of the putative virus was composed of two RNA molecules of 6,128 and 4,161 nucleotides in length, excluding the poly-A tails. Each genome segment contained one large open reading frame (ORF) that shares homology and phylogenetic identity with members of the family Secoviridae. The presence of this new virus in pineapple was confirmed using RT-PCR and Sanger sequencing from six samples collected in Oahu, Hawaii. The name "pineapple secovirus A" (PSVA) is proposed for this putative new sadwavirus.
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Ananas/virología , Genoma Viral , Secoviridae/clasificación , Secoviridae/aislamiento & purificación , Análisis de Secuencia de ADN , Biología Computacional , Orden Génico , Hawaii , Secuenciación de Nucleótidos de Alto Rendimiento , Sistemas de Lectura Abierta , Filogenia , ARN Viral/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Secoviridae/genéticaRESUMEN
We herein report a computational study of the hydrogen bonding in gold-catalyzed ipso-cyclization to diverse polyheterocyclic frameworks. The different roles of these hydrogen bonds are analyzed for the different ipso-cyclization reactions. The fine-tunability of the electronic as well as steric properties of gold counterions contributed substantially to the popularity of the dearomatization reaction, with robust applications in total synthesis and gold catalysis. We have found correlation between the hydrogen bonding parameters and chemoselectivity in gold-catalyzed spirocyclization, playing critical roles in determining the reaction direction of counterion-based enantioselective gold catalysis. The expanded use of counterions via hydrogen bonding interaction can occupy an important role in the future concerning catalyst optimization in gold catalysis.
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CONTEXT: Fructus Meliae toosendan extracts (FMTE) have a good therapeutic effect on coccidiosis, but there is no relevant research on its prophylactic effect on coccidiosis. OBJECTIVE: This study comprehensively evaluates the anticoccidial effect of FMTE. MATERIALS AND METHODS: In vitro, the unsporulated oocysts were treated with serial dilutions of FMTE and incubated for 7 d, and the sporulated oocysts were counted for calculating the median lethal concentration (LC50) of FMTE. In vivo, 180 10-day-old broiler chickens free of coccidiosis were weighted and randomly distributed into six groups: normal group, untreated group, 4 protective groups (positive group and three FMTE groups). From day 10 to day 21, chickens in the three FMTE groups were pre-treated with FMTE at the dosage of 2.5, 5 and 10 g/kg/d, respectively, and chickens in the positive group were pre-treated with qiuliling (10 g/kg/d). On day 14, chickens in all groups except the normal group were orally infected with 1.5 × 104 sporulated oocysts. The clinical symptoms were observed from day 10 to day 21, the anticoccidial index (ACI), tissue lesions, and intestinal microflora were determined on day 21. RESULTS: FMTE showed anti-sporulation effect against E. tenella and the LC50 value was 245.83 µg/mL in vitro. In vivo, FMTE at the dosage of 10 g/kg/d was effective against E. tenella infection, and its ACI value was 162.56, which was higher than the value of positive drug qiuliling (128.81). Discussion and conclusions: FMTE have potent anticoccidial effects, and it presents an alternative anticoccidial agent for avian coccidiosis control.
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Coccidiosis/prevención & control , Meliaceae/química , Extractos Vegetales/farmacología , Enfermedades de las Aves de Corral/prevención & control , Animales , Pollos , Coccidiosis/veterinaria , Coccidiostáticos/administración & dosificación , Coccidiostáticos/aislamiento & purificación , Coccidiostáticos/farmacología , Relación Dosis-Respuesta a Droga , Eimeria tenella/efectos de los fármacos , Frutas , Dosificación Letal Mediana , Oocistos/efectos de los fármacos , Extractos Vegetales/administración & dosificación , Enfermedades de las Aves de Corral/parasitologíaRESUMEN
The area planted with insect-resistant genetically engineered crops expressing Bacillus thuringiensis (Bt) genes has greatly increased in many areas of the world. Given the nearby presence of non-Bt crops (including those planted as refuges) and non-crop habitats, pests targeted by the Bt trait have a choice between Bt and non-Bt crops or weeds, and their host preference may greatly affect insect management and management of pest resistance to Bt proteins. In this study, we examined the oviposition preference of the target pest of Bt rice, Chilo suppressalis, for Bt versus non-Bt rice plants as influenced by previous damage caused by C. suppressalis larvae. The results showed that C. suppressalis females had no oviposition preference for undamaged Bt or non-Bt plants but were repelled by conspecific-damaged plants whether Bt or non-Bt Consequently, C. suppressalis egg masses were more numerous on Bt plants than on neighbouring non-Bt plants both in greenhouse and in field experiments due to the significantly greater caterpillar damage on non-Bt plants. We also found evidence of poorer performance of C. suppressalis larvae on conspecific-damaged rice plants when compared with undamaged plants. GC-MS analyses showed that larval damage induced the release of volatiles that repelled mated C. suppressalis females in wind tunnel experiments. These findings suggest that Bt rice could act as a dead-end trap crop for C. suppressalis and thereby protect adjacent non-Bt rice plants. The results also indicate that the oviposition behaviour of target pest females should be considered in the development of Bt resistance management strategies.
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Bacillus thuringiensis/química , Herbivoria , Mariposas Nocturnas/fisiología , Oryza/química , Oviposición , Control Biológico de Vectores , Animales , Cadena Alimentaria , Cromatografía de Gases y Espectrometría de Masas , Larva/fisiología , Mariposas Nocturnas/crecimiento & desarrollo , Oryza/genética , Plantas Modificadas Genéticamente/química , Plantas Modificadas Genéticamente/genéticaRESUMEN
Genetically engineered (GE) rice lines expressing Lepidoptera-active insecticidal cry genes from the bacterium Bacillus thuringiensis (Bt) have been developed in China. Field surveys indicated that Bt rice harbours fewer rice planthoppers than non-Bt rice although planthoppers are not sensitive to the produced Bt Cry proteins. The mechanisms underlying this phenomenon remain unknown. Here, we show that the low numbers of planthoppers on Bt rice are associated with reduced caterpillar damage. In laboratory and field-cage experiments, the rice planthopper Nilapavata lugens had no feeding preference for undamaged Bt or non-Bt plants but exhibited a strong preference for caterpillar-damaged plants whether Bt or non-Bt. Under open-field conditions, rice planthoppers were more abundant on caterpillar-damaged non-Bt rice than on neighbouring healthy Bt rice. GC-MS analyses showed that caterpillar damage induced the release of rice plant volatiles known to be attractive to planthoppers, and metabolome analyses revealed increased amino acid contents and reduced sterol contents known to benefit planthopper development. That Lepidoptera-resistant Bt rice is less attractive to this important nontarget pest in the field is therefore a first example of ecological resistance of Bt plants to nontarget pests. Our findings suggest that non-Bt rice refuges established for delaying the development of Bt resistance may also act as a trap crop for N. lugens and possibly other planthoppers.
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Proteínas Bacterianas/metabolismo , Endotoxinas/metabolismo , Hemípteros , Proteínas Hemolisinas/metabolismo , Herbivoria , Mariposas Nocturnas , Oryza/metabolismo , Animales , Toxinas de Bacillus thuringiensis , Proteínas Bacterianas/genética , Endotoxinas/genética , Femenino , Preferencias Alimentarias , Proteínas Hemolisinas/genética , Larva , Masculino , Oryza/genética , Plantas Modificadas GenéticamenteRESUMEN
The transgenic rice line T1C-19 provides high resistance to lepidopteran pests because of the synthesis of the Bacillus thuringiensis (Bt) insecticidal protein Cry1C. It thus shows good prospect for commercial planting in China. Species of Cladocera, an order of aquatic arthropods commonly found in aquatic ecosystems such as rice paddies, might be exposed to the insecticidal protein released from Bt-transgenic rice-straw residues. For the study reported herein, we used Daphnia magna (water flea) as a representative of Cladocera to evaluate whether aquatic arthropods are adversely affected when exposed to Bt rice-straw leachates. We exposed D. magna to M4 medium containing various volume percentages of medium that had been incubated with T1C-19 rice straw or rice straw from its non-transformed near-isoline Minghui 63 (MH63) for 21 days. Compared with pure M4 medium (control), the fitness and developmental and reproduction parameters of D. magna decreased significantly when exposed to rice-straw leachates; conversely, no significant differences between the T1C-19 and MH63 rice-straw leachate treatments were observed, indicating that the Bt rice straw leachate did not adversely affect this non-target species.
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Proteínas Bacterianas/toxicidad , Daphnia/efectos de los fármacos , Endotoxinas/toxicidad , Proteínas Hemolisinas/toxicidad , Insecticidas/toxicidad , Plantas Modificadas Genéticamente/metabolismo , Animales , Bacillus thuringiensis/genética , Toxinas de Bacillus thuringiensis , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Bioensayo , Daphnia/fisiología , Endotoxinas/genética , Endotoxinas/metabolismo , Proteínas Hemolisinas/genética , Proteínas Hemolisinas/metabolismo , Oryza/genética , Oryza/metabolismo , ReproducciónRESUMEN
Cry1C is a Bacillus thuringiensis (Bt) insecticidal protein and it can be produced by transgenic rice lines developed in China. Cladocera species are common aquatic arthropods that may be exposed to insecticidal proteins produced in Bt-transgenic plants through ingestion of pollen or crop residues in water. As the cladoceran Daphnia magna plays an important role in the aquatic food chain, it is important to assess the possible effects of Bt crops to this species. To evaluate the safety of the Cry1C protein for D. magna, individuals were exposed to different concentrations of purified Cry1C protein in M4 medium for 21 days. Potassium dichromate (K2Cr2O7), a known toxicant to D. magna, was added to M4 medium as a positive control treatment, and pure M4 medium was used as a negative control. Our results show that developmental, reproductive, and biochemical parameters of D. magna were not significantly different between Cry1C and negative control treatments but were significantly inhibited by the positive control. We thus conclude that D. magna is insensitive to Cry1C.
Asunto(s)
Proteínas Bacterianas/toxicidad , Daphnia/efectos de los fármacos , Endotoxinas/toxicidad , Proteínas Hemolisinas/toxicidad , Contaminantes Químicos del Agua/toxicidad , Animales , Toxinas de Bacillus thuringiensis , Proteínas Bacterianas/genética , China , Relación Dosis-Respuesta a Droga , Endotoxinas/genética , Proteínas Hemolisinas/genética , Oryza/genética , Oryza/metabolismo , Plantas Modificadas Genéticamente/genética , Plantas Modificadas Genéticamente/metabolismo , Pruebas de ToxicidadRESUMEN
MAIN CONCLUSION: A total of 74,745 unigenes were generated and 1975 DEGs were identified. Candidate genes that may be involved in the adventitious root formation of mango cotyledon segment were revealed. Adventitious root formation is a crucial step in plant vegetative propagation, but the molecular mechanism of adventitious root formation remains unclear. Adventitious roots formed only at the proximal cut surface (PCS) of mango cotyledon segments, whereas no roots were formed on the opposite, distal cut surface (DCS). To identify the transcript abundance changes linked to adventitious root development, RNA was isolated from PCS and DCS at 0, 4 and 7 days after culture, respectively. Illumina sequencing of libraries generated from these samples yielded 62.36 Gb high-quality reads that were assembled into 74,745 unigenes with an average sequence length of 807 base pairs, and 33,252 of the assembled unigenes at least had homologs in one of the public databases. Comparative analysis of these transcriptome databases revealed that between the different time points at PCS there were 1966 differentially expressed genes (DEGs), while there were only 51 DEGs for the PCS vs. DCS when time-matched samples were compared. Of these DEGs, 1636 were assigned to gene ontology (GO) classes, the majority of that was involved in cellular processes, metabolic processes and single-organism processes. Candidate genes that may be involved in the adventitious root formation of mango cotyledon segment are predicted to encode polar auxin transport carriers, auxin-regulated proteins, cell wall remodeling enzymes and ethylene-related proteins. In order to validate RNA-sequencing results, we further analyzed the expression profiles of 20 genes by quantitative real-time PCR. This study expands the transcriptome information for Mangifera indica and identifies candidate genes involved in adventitious root formation in cotyledon segments of mango.