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The flower-infecting fungus Ustilaginoidea virens causes rice false smut, which is a severe emerging disease threatening rice (Oryza sativa) production worldwide. False smut not only reduces yield, but more importantly produces toxins on grains, posing a great threat to food safety. U. virens invades spikelets via the gap between the 2 bracts (lemma and palea) enclosing the floret and specifically infects the stamen and pistil. Molecular mechanisms for the U. virens-rice interaction are largely unknown. Here, we demonstrate that rice flowers predominantly employ chitin-triggered immunity against U. virens in the lemma and palea, rather than in the stamen and pistil. We identify a crucial U. virens virulence factor, named UvGH18.1, which carries glycoside hydrolase activity. Mechanistically, UvGH18.1 functions by binding to and hydrolyzing immune elicitor chitin and interacting with the chitin receptor CHITIN ELICITOR BINDING PROTEIN (OsCEBiP) and co-receptor CHITIN ELICITOR RECEPTOR KINASE1 (OsCERK1) to impair their chitin-induced dimerization, suppressing host immunity exerted at the lemma and palea for gaining access to the stamen and pistil. Conversely, pretreatment on spikelets with chitin induces a defense response in the lemma and palea, promoting resistance against U. virens. Collectively, our data uncover a mechanism for a U. virens virulence factor and the critical location of the host-pathogen interaction in flowers and provide a potential strategy to control rice false smut disease.
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Quitina , Flores , Hypocreales , Oryza , Enfermedades de las Plantas , Oryza/microbiología , Oryza/metabolismo , Oryza/genética , Enfermedades de las Plantas/microbiología , Quitina/metabolismo , Flores/microbiología , Hypocreales/patogenicidad , Hypocreales/genética , Hypocreales/metabolismo , Transducción de Señal , Interacciones Huésped-Patógeno , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Virulencia , Factores de Virulencia/metabolismo , Factores de Virulencia/genética , Proteínas Fúngicas/metabolismo , Proteínas Fúngicas/genéticaRESUMEN
Arabidopsis RESISTANCE TO POWDERY MILDEW 8.2 (RPW8.2) is specifically induced by the powdery mildew (PM) fungus (Golovinomyces cichoracearum) in the infected epidermal cells to activate immunity. However, the mechanism of RPW8.2-induction is not well understood. Here, we identify a G. cichoracearum effector that interacts with RPW8.2, named Gc-RPW8.2 interacting protein 1 (GcR8IP1), by a yeast two-hybrid screen of an Arabidopsis cDNA library. GcR8IP1 is physically associated with RPW8.2 with its REALLY INTERESTING NEW GENE finger domain that is essential and sufficient for the association. GcR8IP1 was secreted and translocated into the nucleus of host cell infected with PM. Association of GcR8IP1 with RPW8.2 led to an increase in RPW8.2 in the nucleus. In turn, the nucleus-localized RPW8.2 promoted the activity of the RPW8.2 promoter, resulting in transcriptional self-amplification of RPW8.2 to boost immunity at infection sites. Additionally, ectopic expression or host-induced gene silencing of GcR8IP1 supported its role as a virulence factor in PM. Altogether, our results reveal a mechanism of RPW8.2-dependent defense strengthening via altered partitioning of RPW8.2 and transcriptional self-amplification triggered by a PM fungal effector, which exemplifies an atypical form of effector-triggered immunity.
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Proteínas de Arabidopsis , Arabidopsis , Ascomicetos , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Resistencia a la Enfermedad , Ascomicetos/fisiología , Enfermedades de las Plantas/microbiologíaRESUMEN
Gigantol is a phenolic component of precious Chinese medicine Dendrobii Caulis, which has many pharmacological activities such as prevent tumor and diabetic cataract. This paper aimed to investigate the molecular mechanism of gigantol in transmembrane transport in human lens epithelial cells(HLECs). Immortalized HLECs were cultured in vitro and inoculated in the laser scanning confocal microscopy(LSCM) medium at 5 000 cells/mL. The fluorescence distribution and intensity of gigantol marked by fluorescence in HLECs were observed by LSCM, and the absorption and distribution of gigantol were expressed as fluorescence intensity. The transmembrane transport process of gigantol in HLECs were monitored. The effects of time, temperature, concentration, transport inhibitors, and different cell lines on the transmembrane absorption and transport of gigantol were compared. HLECs were inoculated on climbing plates of 6-well culture plates, and the ultrastructure of HLECs was detected by atomic force microscopy(AFM) during the transmembrane absorption of non-fluorescent labeled gigantol. The results showed that the transmembrane absorption of gigantol was in time and concentration-dependent manners, which was also able to specifically target HLECs. Energy and carrier transport inhibitors reduced gigantol absorption by HLECs. During transmembrane process of gigantol, the membrane surface of HLECs became rougher and presented different degrees of pits, indicating that the transmembrane transport of gigantol was achieved by active absorption of energy and carrier-mediated endocytosis.
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Bibencilos , Catarata , Cristalino , Humanos , Cristalino/metabolismo , Cristalino/patología , Catarata/metabolismo , Catarata/patología , Catarata/prevención & control , Bibencilos/química , Bibencilos/metabolismo , Bibencilos/farmacología , Células Epiteliales , Células Cultivadas , ApoptosisRESUMEN
Rice production is threatened by multiple pathogens. Breeding cultivars with broad-spectrum disease resistance is necessary to maintain and improve crop production. Previously we found that overexpression of miR160a enhanced rice blast disease resistance. However, it is unclear whether miR160a also regulates resistance against other pathogens, and what the downstream signaling pathways are. Here, we demonstrate that miR160a positively regulates broad-spectrum resistance against the causative agents of blast, leaf blight and sheath blight in rice. Mutations of miR160a-targeted Auxin Response Factors result in different alteration of resistance conferred by miR160a. miR160a enhances disease resistance partially by suppressing ARF8, as mutation of ARF8 in MIM160 background partially restores the compromised resistance resulting from MIM160. ARF8 protein binds directly to the promoter and suppresses the expression of WRKY45, which acts as a positive regulator of rice immunity. Mutation of WRKY45 compromises the enhanced blast resistance and bacterial leaf blight resistance conferred by arf8 mutant. Overall, our results reveal that a microRNA coordinates rice broad-spectrum disease resistance by suppressing multiple target genes that play different roles in disease resistance, and uncover a new regulatory pathway mediated by the miR160a-ARF8 module. These findings provide new resources to potentially improve disease resistance for breeding in rice.
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Magnaporthe , Oryza , Resistencia a la Enfermedad/genética , Magnaporthe/metabolismo , Oryza/metabolismo , Enfermedades de las Plantas/microbiología , Proteínas de Plantas/metabolismo , FitomejoramientoRESUMEN
The detection method of characteristic spectrum for reference samples was established by preparing 15 batches of the reference samples of Huagan Decoction, and the peak attribution and the similarity range in the characteristic spectrum were clarified. The ranges of paste-forming rate, content, and transfer rate of the index components including geniposide, paeonol, and paeoniflorin were analyzed. The key quality attribute of the reference samples of Huagan Decoction was defined. The results showed that the 15 batches of the reference samples of Huagan Decoction had good similarities in the characteristic spectrum, which were all higher than 0.9. According to the information of characteristic peak, there were 18 characteristic peaks in the whole prescription, including seven common characteristic peaks from green tangerine peel and dried tangerine peel, four characteristic peaks from tree peony root bark(three of them were common characteristic peaks from tree peony root bark and red peony root), five characteristic peaks from cape jasmine fruit, one characteristic peak from paniculate bolbostemma, and one characteristic peak from oriental waterplantain rhizome.The paste-forming rate of the 15 batches of reference samples was 14.73%-18.83%. The content of geniposide was 1.68%-2.87%, with the average transfer rate of 70.05%±11.13%. The content of paeonol was 0.10%-0.16%, with the average transfer rate of 9.38%±1.78%. The content of paeoniflorin was 1.94%-2.74%, with the average transfer rate of 36.69%±4.63%. This study analyzed the quality value transfer of the reference samples of Huagan Decoction by the evaluation mode of combining the characteristic spectrum, the paste-forming rate, and the content of index components. The findings of this study initially established a stable and feasible standard decoction evaluation method and provided references for the quality control and the subsequent development of relevant preparations of Huagan Decoction.
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Medicamentos Herbarios Chinos , Paeonia , Cromatografía Líquida de Alta Presión , Prescripciones , Control de CalidadRESUMEN
Circular RNAs (circRNAs) play roles in various biological processes, but their functions in the rice (Oryza sativa) response to Magnaporthe oryzae remain elusive. Here, we demonstrate that circRNAs are involved in the rice-M. oryzae interaction using comparative circRNA-sequencing and transgenic approaches. We identified 2932 high-confidence circRNAs from young leaves of the blast-resistant accession International Rice Blast Line Pyricularia-Kanto51-m-Tsuyuake (IR25) and the blast-susceptible accession Lijiangxin Tuan Heigu (LTH) under M oryzae-infected or uninfected conditions; 636 were detected specifically upon M oryzae infection. The circRNAs in IR25 were significantly more diverse than those in LTH, especially under M. oryzae infection. Particularly, the number of circRNAs generated per parent gene was much higher in IR25 than in LTH and increased in IR25 but decreased in LTH upon M. oryzae infection. The higher diversity of circRNAs in IR25 was further associated with more frequent 3' and 5' alternative back-splicing and usage of complex splice sites. Moreover, a subset of circRNAs was differentially responsive to M oryzae in IR25 and LTH. We further confirmed that circR5g05160 promotes rice immunity against M oryzae Therefore, our data indicate that circRNA diversity is associated with different responses to M oryzae infection in rice and provide a starting point to investigate a new layer of regulation in the rice-M oryzae interaction.
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Magnaporthe/patogenicidad , Oryza/microbiología , Enfermedades de las Plantas/microbiología , ARN Circular/genética , Regulación de la Expresión Génica de las Plantas/genética , Interacciones Huésped-Patógeno , Enfermedades de las Plantas/genéticaRESUMEN
Rice false smut has emerged as a serious grain disease in rice production worldwide. The disease is characterized by the transformation of individual rice florets into false smut balls, which is caused by the fungal pathogen Ustilaginoidea virens. To date, little is known about the host factors required for false smut ball formation by U. virens. In this study, we identified histological determinants for the formation of false smut balls by inoculating U. virens into rice floral mutants defective with respect to individual floral parts. The results showed that U. virens could form mature false smut balls in rice floral mutants with defective pistils, but failed to develop false smut balls in the superwoman mutant lacking stamens, identifying that U. virens requires rice stamens to complete its infection cycle. Comparative transcriptome analysis indicated a list of candidate host genes that may facilitate nutrient acquisition by U. virens from the rice stamens, such as SWEET11, SWEET14 and SUT5, and genes involved in the biosynthesis of trehalose and raffinose family sugars. These data pinpoint rice stamens as the key target organ of U. virens infection and provide a valuable starting point for dissecting the molecular mechanism of false smut ball formation.
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Flores/microbiología , Hypocreales/crecimiento & desarrollo , Oryza/microbiología , Hypocreales/genética , Hypocreales/metabolismo , Proteínas de Transporte de Membrana/genética , Enfermedades de las Plantas/microbiología , Rafinosa/biosíntesis , Transcriptoma/genética , Trehalosa/biosíntesisRESUMEN
We demonstrate a high-power, high-energy chirped-pulse amplification (CPA) system based on three Yb:YAG amplifiers and a chirped-volume Bragg grating (CVBG). With an all-fiber laser as the seed light, a Yb:YAG rod amplifier and two Yb:YAG single-crystal fiber (SCF) amplifiers as the amplification stages, a laser power of 96 W at 200 kHz repetition rate corresponding to a pulse energy of 0.48 mJ has been generated. The stability of different output power has been measured and compared. To the best of our knowledge, this is the first report on a stable 100 W-level laser with sub-mJ pulse energy based on SCF. The beam quality M2 of different output lasers has also been measured, which is below 1.55 when the output power is 92 W. The amplified laser is seeded into the CVBG to be compressed, and a compression efficiency of 0.724 has been obtained with an output power of 67.8 W and pulse duration of 2.5 ps. The ultrafast CPA system delivering high pulse energy (sub-mJ) with hundreds of kHz repetition rate is expected to be used as the driving source of high-flux high-harmonic generation after further compression.
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OBJECTIVE: To observe the effect and mechanism of Dendrobium candidum polysaccharides (DCP) in promoting hair growth, in order to lay a foundation for the development and utilization of D. candidum. METHOD: The water-extraction and alcohol-precipitation method was adopted to extract DCP, and the phenol-sulphuric acid method was used to determine its content. Thirty C57BL6J mice were collected to establish the hair loss model with hair removal cream. They were randomly divided into the control group, the positive control group and the DCP group, and given 0.2 mL of ultra-pure water, minoxidil tincture and DCP (5.0 g x L(-1)) 21 days. The mice hair growth scoring standard was adopted to evaluate the hair growth of C57BL/6J mice at 7, 14 d. The hairs in unit hair-losing areas of treated C57BL/6J mice at 21 d were weighed to evaluate the effect of DCP on the promotion of hair growth. MTT assay and RT-PCR method were used to evaluate the effect of DCP on the proliferatin of HaCaT cells and the mRNA expression of VEGF in HaCaT cells. RESULT: The extraction percent of DCP was 29.87%, and its content was 79.65%. The average scores for the hair growth and weight of C57BL/6J mice of DCP group were much higher than the control group. The survival rate and mRNA expression of VEGF of HaCaT cells were much higher than the control group. CONCLUSION: DCP has the effect in promoting hair growth. Its mechanism may be related to the up-regulation of the mRNA expression of VEGF.
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Dendrobium/química , Cabello/efectos de los fármacos , Cabello/crecimiento & desarrollo , Polisacáridos/farmacología , Animales , Línea Celular , Proliferación Celular/efectos de los fármacos , Femenino , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , Ratones , Ratones Endogámicos C57BL , ARN Mensajero/genética , ARN Mensajero/metabolismo , Factor A de Crecimiento Endotelial Vascular/genéticaRESUMEN
The orexin system is closely related to the pathogenesis of Alzheimer's disease (AD). Orexin-A aggravates cognitive dysfunction and increases amyloid ß (Aß) deposition in AD model mice, but studies of different dual orexin receptor (OXR) antagonists in AD have shown inconsistent results. Our previous study revealed that OX1R blockade aggravates cognitive deficits and pathological progression in 3xTg-AD mice, but the effects of OX2R and its potential mechanism in AD have not been reported. In the present study, OX2R was blocked by oral administration of the selective OX2R antagonist MK-1064, and the effects of OX2R blockade on cognitive dysfunction and neuropsychiatric symptoms in 3xTg-AD mice were evaluated via behavioral tests. Then, immunohistochemistry, western blotting, and ELISA were used to detect Aß deposition, tau phosphorylation, and neuroinflammation, and electrophysiological and wheel-running activity recording were recorded to observe hippocampal synaptic plasticity and circadian rhythm. The results showed that OX2R blockade ameliorated cognitive dysfunction, improved LTP depression, increased the expression of PSD-95, alleviated anxiety- and depression-like behaviors and circadian rhythm disturbances in 3xTg-AD mice, and reduced Aß pathology, tau phosphorylation, and neuroinflammation in the brains of 3xTg-AD mice. These results indicated that chronic OX2R blockade exerts neuroprotective effects in 3xTg-AD mice by reducing AD pathology at least partly through improving circadian rhythm disturbance and the sleep-wake cycle and that OX2R might be a potential target for the prevention and treatment of AD; however, the potential mechanism by which OX2R exerts neuroprotective effects on AD needs to be further investigated.
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Enfermedad de Alzheimer , Disfunción Cognitiva , Modelos Animales de Enfermedad , Progresión de la Enfermedad , Ratones Transgénicos , Antagonistas de los Receptores de Orexina , Animales , Enfermedad de Alzheimer/metabolismo , Enfermedad de Alzheimer/tratamiento farmacológico , Enfermedad de Alzheimer/patología , Ratones , Antagonistas de los Receptores de Orexina/farmacología , Disfunción Cognitiva/tratamiento farmacológico , Receptores de Orexina/metabolismo , Péptidos beta-Amiloides/metabolismo , Masculino , Hipocampo/efectos de los fármacos , Hipocampo/patología , Hipocampo/metabolismoRESUMEN
Cognitive dysfunction is the main clinical manifestation of Alzheimer's disease (AD). Previous research found that elevated orexin level in the cerebrospinal fluid was closely related to the course of AD, and orexin-A treatment could increase amyloid ß protein (Aß) deposition and aggravate spatial memory impairment in APP/PS1 mice. Furthermore, recent research found that dual orexin receptor (OXR) antagonist might affect Aß level and cognitive dysfunction in AD, but the effects of OX1R or OX2R alone is unreported until now. Considering that OX1R is highly expressed in the hippocampus and plays important roles in learning and memory, the effects of OX1R in AD cognitive dysfunction and its possible mechanism should be investigated. In the present study, selective OX1R antagonist SB-334867 was used to block OX1R. Then, different behavioral tests were performed to observe the effects of OX1R blockade on cognitive function of 3xTg-AD mice exhibited both Aß and tau pathology, in vivo electrophysiological recording and western blot were used to investigate the potential mechanism. The results showed that chronic OX1R blockade aggravated the impairments of short-term working memory, long-term spatial memory and synaptic plasticity in 9-month-old female 3xTg-AD mice, increased levels of soluble Aß oligomers and p-tau, and decreased PSD-95 expression in the hippocampus of 3xTg-AD mice. These results indicate that the detrimental effects of SB-334867 on cognitive behaviors in 3xTg-AD mice are closely related to the decrease of PSD-95 and depression of in vivo long-term potentiation (LTP) caused by increased Aß oligomers and p-tau.
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Enfermedad de Alzheimer , Disfunción Cognitiva , Ratones , Animales , Femenino , Enfermedad de Alzheimer/complicaciones , Enfermedad de Alzheimer/tratamiento farmacológico , Enfermedad de Alzheimer/metabolismo , Péptidos beta-Amiloides/metabolismo , Orexinas/metabolismo , Ratones Transgénicos , Modelos Animales de Enfermedad , Disfunción Cognitiva/tratamiento farmacológico , Disfunción Cognitiva/etiología , Disfunción Cognitiva/patología , Hipocampo/metabolismo , Antagonistas de los Receptores de Orexina/farmacología , Proteínas tau/metabolismo , Precursor de Proteína beta-Amiloide/metabolismoRESUMEN
Orexin and its receptors are closely related to the pathogenesis of Alzheimer's disease (AD). Although the expression of orexin system genes under physiological condition has circadian rhythm, the diurnal characteristics of orexin system genes, and its potential role in the pathogenesis in AD are unknown. In the present study, we hope to elucidate the diurnal characteristics of orexin system genes at the early stage of AD, and to investigate its potential role in the development of AD neuropathology. We firstly detected the mRNA levels of orexin system genes, AD risk genes and core clock genes (CCGs) in hypothalamus and hippocampus in 6-month-old male 3xTg-AD mice and C57BL/6J (wild type, WT) control mice, then analyzed diurnal expression profiles of all genes using JTK_CYCLE algorithm, and did the correlation analysis between expression of orexin system genes and AD risk genes or CCGs. In addition, the expression of ß-amyloid protein (Aß) and phosphorylated tau (p-tau) protein were measured. The results showed that the diurnal mRNA expression profiles of PPO, OX1R, OX2R, Bace2, Bmal1, Per1, Per2 and Cry1 in the hypothalamus, and gene expression of OX1R, OX2R, Bace1, Bmal1, Per1 and Cry2 in the hippocampus in 3xTg-AD mice were different from that in WT mice. Furthermore, there is positive correlation between orexin system genes and AD risk genes or CCGs in the brain in 3xTg-AD mice. In addition, the expression of Aß and p-tau in hippocampus in 3xTg-AD mice were significantly increased, and the expression of p-tau is higher in night than in day. These results indicate that the abnormal expression profiles of orexin system genes and its interaction with AD risk genes or CCGs might exert important role in the pathogenesis of AD, which will increase the expression of Aß and p-tau, and accelerate the development of AD.
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Enfermedad de Alzheimer , Orexinas , Animales , Masculino , Ratones , Enfermedad de Alzheimer/metabolismo , Péptidos beta-Amiloides/genética , Péptidos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/genética , Precursor de Proteína beta-Amiloide/metabolismo , Secretasas de la Proteína Precursora del Amiloide/genética , Secretasas de la Proteína Precursora del Amiloide/metabolismo , Factores de Transcripción ARNTL/metabolismo , Ácido Aspártico Endopeptidasas/metabolismo , Modelos Animales de Enfermedad , Ratones Endogámicos C57BL , Ratones Transgénicos , Orexinas/genética , ARN Mensajero/genética , Proteínas tau/genética , Proteínas tau/metabolismoRESUMEN
Crops with broad-spectrum resistance loci are highly desirable in agricultural production because these loci often confer resistance to most races of a pathogen or multiple pathogen species. Here we discover a natural allele of proteasome maturation factor in rice, UMP1R2115, that confers broad-spectrum resistance to Magnaporthe oryzae, Rhizoctonia solani, Ustilaginoidea virens and Xanthomonas oryzae pv. oryzae. Mechanistically, this allele increases proteasome abundance and activity to promote the degradation of reactive oxygen species-scavenging enzymes including peroxidase and catalase upon pathogen infection, leading to elevation of H2O2 accumulation for defence. In contrast, inhibition of proteasome function or overexpression of peroxidase/catalase-encoding genes compromises UMP1R2115-mediated resistance. More importantly, introduction of UMP1R2115 into a disease-susceptible rice variety does not penalize grain yield while promoting disease resistance. Our work thus uncovers a broad-spectrum resistance pathway integrating de-repression of plant immunity and provides a valuable genetic resource for breeding high-yield rice with multi-disease resistance.
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Magnaporthe , Oryza , Resistencia a la Enfermedad/genética , Oryza/genética , Complejo de la Endopetidasa Proteasomal/metabolismo , Catalasa/genética , Catalasa/metabolismo , Alelos , Peróxido de Hidrógeno/metabolismo , Magnaporthe/metabolismo , Fitomejoramiento , Enfermedades de las Plantas , Regulación de la Expresión Génica de las PlantasRESUMEN
A portable method of group velocity measurement is proposed based on a self-seeded gain-switched laser. The calculated group velocity in the optical fiber is obtained by measuring the round-trip frequencies of the gain-switched laser diode with different external cavities, and only a 2 m long fiber is needed. The measurement can be accomplished without oscilloscope or optical spectrum analyzer. The error associated with this test is within 0.65%, which is limited by the jitter of the voltage-controlled oscillator. Its spectrum resolution is 0.1 nm.
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Macrobenthos can reflect the cumulative effect of various ecological threats on the water environment and are closely related to the health of river ecosystems. In this study, taking the North Canal River basin, a typical basin in Beijing, as an example, ecological data from 34 stations were investigated in the summer of 2015. Characteristics of the macrobenthos communities were analyzed, and driving environmental factors were identified using typical correspondence analysis. Thresholds and response species of those driving environmental factors were conducted using the thresholds indicator taxa analysis (TITAN). In this study, the health status of the river ecosystem was evaluated by the multi-metrics method and benthic index of biotic integrity (B-IBI). The benthic community was dominated by pollution-tolerant aquatic insects and mollusks, with a low-level Shannon-wiener diversity index between 0-1.01; fluoride, biochemical oxygen demand, ammonia-nitrogen, and total phosphorus were driving environmental factors influencing the community structure of macrobenthos. Indicator species of ammonia-nitrogen were identified by the TITAN in the North Canal River basin with a threshold range of 1.09-6.94 mg·L-1; three indicator species of total phosphorus were identified with a threshold range of 0.48-1.27 mg·L-1, which were all positive response species. According to the health assessment, the river ecosystem in the North Canal River basin was generally unhealthy, and the upstream ecosystem was better than that downstream; the health conditions in the mountainous areas of Changping district were the best, whereas those in Chaoyang and central city districts were the worst. This study can provide a basis for ecological restoration and pollution control of rivers and also provide a reference for the water ecological civilization construction in other cities.
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Ecosistema , Agua , Beijing , China , Monitoreo del Ambiente , RíosRESUMEN
Flower opening and stigma exertion are two critical traits for cross-pollination during seed production of hybrid rice (Oryza sativa L.). In this study, we demonstrate that the miR167d-ARFs module regulates stigma size and flower opening that is associated with the elongation of stamen filaments and the cell arrangement of lodicules. The overexpression of miR167d (OX167d) resulted in failed elongation of stamen filaments, increased stigma size, and morphological alteration of lodicule, resulting in cleistogamy. Blocking miR167d by target mimicry also led to a morphological alteration of the individual floral organs, including a reduction in stigma size and alteration of lodicule cell morphology, but did not show the cleistogamous phenotype. In addition, the four target genes of miR167d, namely ARF6, ARF12, ARF17, and ARF25, have overlapping functions in flower opening and stigma size. The loss-of-function of a single ARF gene did not influence the flower opening and stigma size, but arf12 single mutant showed a reduced plant height and aborted apical spikelets. However, mutation in ARF12 together with mutation in either ARF6, ARF17, or ARF25 led to the same defective phenotypes that were observed in OX167d, including the failed elongation of stamen filaments, increased stigma size, and morphological alteration of lodicule. These findings indicate that the appropriate expression of miR167d is crucial and the miR167d-ARFs module plays important roles in the regulation of flower opening and stigma size in rice.
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Grain formation is fundamental for crop yield but is vulnerable to abiotic and biotic stresses. Rice grain production is threatened by the false smut fungus Ustilaginoidea virens, which specifically infects rice floral organs, disrupting fertilization and seed formation. However, little is known about the molecular mechanisms of the U. virens-rice interaction and the genetic basis of floral resistance. Here, we report that U. virens secretes a cytoplasmic effector, UvCBP1, to facilitate infection of rice flowers. Mechanistically, UvCBP1 interacts with the rice scaffold protein OsRACK1A and competes its interaction with the reduced nicotinamide adenine dinucleotide phosphate oxidase OsRBOHB, leading to inhibition of reactive oxygen species (ROS) production. Although the analysis of natural variation revealed no OsRACK1A variants that could avoid being targeted by UvCBP1, expression levels of OsRACK1A are correlated with field resistance against U. virens in rice germplasm. Overproduction of OsRACK1A restores the OsRACK1A-OsRBOHB association and promotes OsRBOHB phosphorylation to enhance ROS production, conferring rice floral resistance to U. virens without yield penalty. Taken together, our findings reveal a new pathogenic mechanism mediated by an essential effector from a flower-specific pathogen and provide a valuable genetic resource for balancing disease resistance and crop yield.
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Oryza , Oryza/genética , Oryza/microbiología , Especies Reactivas de Oxígeno , Enfermedades de las Plantas/genética , Enfermedades de las Plantas/microbiología , Flores/genética , Flores/microbiología , SemillasRESUMEN
Magnaporthe oryzae is the causative agent of rice blast, a devastating disease in rice worldwide. Based on the gene-for-gene paradigm, resistance (R) proteins can recognize their cognate avirulence (AVR) effectors to activate effector-triggered immunity. AVR genes have been demonstrated to evolve rapidly, leading to breakdown of the cognate resistance genes. Therefore, understanding the variation of AVR genes is essential to the deployment of resistant cultivars harboring the cognate R genes. In this study, we analyzed the nucleotide sequence polymorphisms of eight known AVR genes, namely, AVR-Pita1, AVR-Pii, AVR-Pia, AVR-Pik, AVR-Pizt, AVR-Pi9, AVR-Pib, and AVR-Pi54 in a total of 383 isolates from 13 prefectures in the Sichuan Basin. We detected the presence of AVR-Pik, AVR-Pi54, AVR-Pizt, AVR-Pi9, and AVR-Pib in the isolates of all the prefectures, but not AVR-Pita1, AVR-Pii, and AVR-Pia in at least seven prefectures, indicating loss of the three AVRs. We also detected insertions of Pot3, Mg-SINE, and indels in AVR-Pib, solo-LTR of Inago2 in AVR-Pizt, and gene duplications in AVR-Pik. Consistently, the isolates that did not harboring AVR-Pia were virulent to IRBLa-A, the monogenic line containing Pia, and the isolates with variants of AVR-Pib and AVR-Pizt were virulent to IRBLb-B and IRBLzt-t, the monogenic lines harboring Pib and Piz-t, respectively, indicating breakdown of resistance by the loss and variations of the avirulence genes. Therefore, the use of blast resistance genes should be alarmed by the loss and nature variations of avirulence genes in the blast fungal population in the Sichuan Basin.
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OBJECTIVE: To investigate the therapeutic effect of PI3Kgamma inhibitor AS605240 on cardiac hypertrophy and cardiac fibrosis induced by Isoproterenol in rats. METHODS: Wistar rats were randomly divided into three groups (n = 10), control group, ISO group (vehicle group) and AS605240 group. The rats in control group without any treatment. The rats in ISO and AS605240 group were given ISO 10 mg/kg for 3 days and 5 mg/kg for another 11 days by subcutaneous injection to prepare the animal model of cardiac fibrosis. Rats in AS605240 group were given AS605240 50 mg/(kg x d) by intraperitoneal injection continuously for 14 days. The vehicle group received the intraperitoneal injection of an equal volume of 0.5% carboxymethylcellulose. Twenty-four hours after the last treatment, rats were sacrificed. Heart, body weight, cardiac function and the CVF were measured. RESULTS: Compared with the control group, the HW/BW of ISO group was increased significantly (P < 0.05) with a increased collagen inter cardiac muscle cells (P < 0. 05). Compared with ISO group, histological examination of the heart showed that AS605240 significantly relieved the rat cardiac fibrosis and reduced heart/body weight ratios in experimental cardiac fibrosis (P < 0.05). CONCLUSION: AS605240 may be an effective antagonist for cardiac hypertrophy and cardiac fibrosis.
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Cardiomegalia/tratamiento farmacológico , Isoproterenol/farmacología , Miocardio/patología , Proteínas/antagonistas & inhibidores , Quinoxalinas/farmacología , Tiazolidinedionas/farmacología , Animales , Cardiomegalia/inducido químicamente , Fibrosis/inducido químicamente , Fibrosis/tratamiento farmacológico , Masculino , Complejo de la Endopetidasa Proteasomal , Quinoxalinas/uso terapéutico , Distribución Aleatoria , Ratas , Ratas Wistar , Tiazolidinedionas/uso terapéuticoRESUMEN
OBJECTIVE: To determine the antitumor effects of the recombinant human RhoB with low-dose cisplatin in lung carcinoma models. METHODS: The pVITRO2-RhoB recombinant was constructed and transfected into A549 cells. Its expression and the inhibition effect to the A549 cells were observed models. A549 lung carcinoma mice were treated with either RhoB or cisplatin or both agents together. And the change of tumor size, the survive time of mice, the apoptosis of tumor were also observed. RESULTS: The pVITRO2-RhoB recombinant was constructed successfully. This recombinant could inhibit the growth and promote the apoptosis of A594 in vitro. Mice treated with RhoB or low-dose cisplatin treatment individually resulted in tumor inhibition to a certain extent. Mice treated with combination of RhoB and low-dose cisplatin resulted in synergistic antitumor activity with more effective tumor inhibition (P < 0.05) and longer survival (P < 0.05). TUNEL analysis of tumors exhibited that RhoB in combination with cisplatin led to the increased rate of apoptosis (P < 0.05). CONCLUSION: Our data demonstrated that RhoB could increase the sensitivity of lung carcinoma to cisplatin, resulting in enhanced anti-tumor activity. These results suggest that combination with recombinant human RhoB with chemotherapy drugs may be an effective approach in the treatment of lung carcinoma.