摘要 :
The resistance to Tobamovirus in Capsicum spp. has been known to be controlled by five different alleles (L~°, L~1, L~2, L~3, and L~4) of L locus on the telomere of long arm of pepper chromosome 11. To develop a set of molecular ...
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The resistance to Tobamovirus in Capsicum spp. has been known to be controlled by five different alleles (L~°, L~1, L~2, L~3, and L~4) of L locus on the telomere of long arm of pepper chromosome 11. To develop a set of molecular markers differentiating all the alleles of L locus, we used five pepper differential hosts including Capsicum annuum Early California Wonder (ECW, UU), C annuum Tisana (L L ), C. annuum Criollo de Morelos 334 (CM334, L~2L~2), Capsicum chinense PI 159236 (L~3L~3), and Capsicum chacoense PI 260429 (L~4L~4). Developing a series of CAPS or SCAR markers specifically linked to the alleles was allowed by the sequence comparison of PCR amplicons of the L~3-linked markers (189D23M, A339, and 253A1R) and BAC sequences (FJ597539 and FJ597541) in the pepper differentials. Genotypes deduced by these markers in 48 out of 53 F_1 hybrids of commercial pepper varieties were consistent with their phenotypes by bioassay using Tobamovirus pathotypes (Po, Pi, and Pi,2). Consequently, these markers can be useful to differentiate L alleles and for breeding Tobamovirus resistance in pepper with marker-assisted selection.
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Capsicum is an important offseason vegetable crop among the farmers of Himachal Pradesh (H.P.) and widely grown under protected cultivation. In recent years extensive use of hybrids from many unknown sources under the polyhouse cu...
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Capsicum is an important offseason vegetable crop among the farmers of Himachal Pradesh (H.P.) and widely grown under protected cultivation. In recent years extensive use of hybrids from many unknown sources under the polyhouse cultivation has escalated the incidence of many viral diseases including seed-borne viruses like Pepper mild mottle virus (PMMoV). The use of genetic resistance is the most feasible strategy for plant virus management. In this study a panel of one hundred and seventy-seven capsicum genotypes including the local landraces, high yielding recommended cultivars and exotic collections were screened for resistance against PMMoV-HPl isolate. The reaction of the genotypes was recorded and validated using Double antibody sandwich-Enzyme linked immunosorbant assay (DAS-ELISA) and reverse transcriptase-Polymerase chain reaction (RT-PCR). Out of 177 lines, only two accessions PI-159236 and PI-260429 have shown resistance against PMMoV-HPl. All the other accession lines were susceptibleto the disease showing mottling, puckering and mild mosaic on the leaves after 10-14 days of inoculations. The DAS-ELISA assay using PMMoV specific antiserum exhibited strong reaction with an OD value at 405 nm between the range of 0.666-1.564 which wasalmost 3-4 times more than the negative control (0.181) in susceptible accessions. In RT-PCR, susceptible accessions yielded an amplification product of-730 bp, while no amplification was observed in the case of PI-159236 and PI-260429 inoculated with PMMoV-HPl. These two lines can be used in breeding programs to develop PMMoV resistant high yielding cultivar.
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We investigated the roles of different concentrations of chemical synthetic spherical silver nanoparticles (AgNPs) in protecting pepper seedlings of the Mecca region, which were naturally and artificially infected by the pepper mi...
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We investigated the roles of different concentrations of chemical synthetic spherical silver nanoparticles (AgNPs) in protecting pepper seedlings of the Mecca region, which were naturally and artificially infected by the pepper mild mottle virus (PMMoV). The virus shows many infection symptoms, including pepper leaf deformation with filiform leaves and severe mosaic symptoms. Our study focused on the antiviral activity of different concentrations of spherical nanoparticles in controlling PMMoV infecting pepper seedlings. PMMoV identification was confirmed via DAS-ELISA using the following antiserum: PMMoV, cucumber mosaic virus (CMV), tobacco mosaic virus (TMV), tomato mosaic virus (ToMV), potato virus Y (PVY), and tomato spotted wilt virus (TSWV). The presence of PMMoV was confirmed using electron microscopy and reverse transcription polymerase chain reaction (RT-PCR). We evaluated the effects of exogenously applied different concentrations of AgNPs on CMV infection rate, infection severity, virus concentration, and the concentrations of photosynthetic pigments chlorophyll a, chlorophyll b, carotenoid content, phenolic compounds, and protein components in virus-infected plant cells that were treated with three different concentration of nanoparticles (200, 300, and 400 μg/L) compared to the positive and negative control.
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摘要 :We used SuperSAGE, an improved version of serial analysis of gene expression, to explore transcriptome changes early in the L 3 -mediated resistance response of pepper plants against a tobamovirus. Capsicum chinense plants homozyg...
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We used SuperSAGE, an improved version of serial analysis of gene expression, to explore transcriptome changes early in the L 3 -mediated resistance response of pepper plants against a tobamovirus. Capsicum chinense plants homozygous for the L 3 resistance gene were infected with virulent and avirulent strains of Pepper mild mottle virus (PMMoV). Plants were maintained at a temperature nonpermissive for the resistance gene to allow the viruses to spread, then transferred to a permissive temperature for 3 h and subsequently analyzed. In the incompatible reaction, we selected 152 SuperSAGE tags (each 26 nucleotides long) possibly corresponding to upregulated genes, and 84 tags for downregulated genes. Approximately 70% of tags had matching ESTs in the genus Capsicum, other genera within the Solanaceae and/or other families of plants. More than 90% of tags with EST matches could be annotated with either functionally characterized or uncharacterized proteins. We compared genes annotated by SuperSAGE tags and those annotated by partial cDNA that was obtained using the SuperSAGE tag sequences as rapid amplification of the cDNA ends-PCR primers. Of genes annotated by SuperSAGE tags, c. 90% were consistent with those annotated by longer cDNA sequences. We cloned 17 full-length cDNAs from different SuperSAGE tags and confirmed that these genes were upregulated during normal infection in the incompatible interaction. We identified several early resistance response genes including a Ran/TC4 protein and a β-oxidation multifunctional protein, indicating that SuperSAGE is a powerful tool for investigating plant–pathogen interactions.
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One of the main purposes of drinking water treatment is to reduce turbidity originating from clay particles. Relatively little is known about the removal of other types of particles, including conventionally sized powdered activat...
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One of the main purposes of drinking water treatment is to reduce turbidity originating from clay particles. Relatively little is known about the removal of other types of particles, including conventionally sized powdered activated carbon (PAC) and superfine PAC (SPAC), which are intentionally added during the treatment process; microplastic particles; and viruses. To address this knowledge gap, we conducted a preliminary investigation in full-scale water treatment plants and then studied the removal of these particles during coagulation-flocculation, sedimentation, and rapid sand filtration (CSF) in bench-scale experiments in which these particles were present together. Numbers of all target particles were greatly decreased by coagulation-flocculation and sedimentation (CS). Subsequent rapid sand filtration greatly reduced the concentrations of PAC and SPAC but not the concentrations of viruses, microplastic particles, and clay particles. Overall removal rates by CSF were 4.6 logs for PAC and SPAC, 3.5 logs for viruses, 2.9 logs for microplastics, and 2.8 logs for clay. The differences in removals were not explained by particle sizes or zeta potentials. However, for clays, PAC and SPAC, for which the particle size distributions were wide, smaller particles were less efficiently removed. The ratios of both clay to PAC and clay to SPAC particles increased greatly after rapid sand filtration because removal rates of PAC and SPAC particles were about 2 logs higher than removal rates of clay particles. The trend of greater reduction of PAC concentrations than turbidity was confirmed by measurements made in 14 full-scale water purification plants in which residual concentrations of PAC in treated water were very low, 40-200 particles/mL. Clay particles therefore accounted for most of the turbidity in sand filtrate, even though PAC was employed. The removal rate of microplastic particles was comparable to that of clays. Sufficient turbidity removal would therefore provide comparable removal of microplastics. We investigated the effect of mechanical/photochemical weathering on the removal of microplastics via CSF. Photochemical weathering caused a small increment in the removal rate of microplastics during CS but a small reduction in the removal rate of microplastics during rapid sand filtration; mechanical weathering decreased the removal rate via CS but increased the removal rate via rapid sand filtration. The changes of removal of microplastics might have been caused by changes of their zeta potential.
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Background: Wastewater-based epidemiology (WBE) has been implemented to monitor surges of COVID-19. Yet, multiple factors impede the usefulness of WBE and quantitative adjustment may be required. Aim: We aimed to model the relatio...
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Background: Wastewater-based epidemiology (WBE) has been implemented to monitor surges of COVID-19. Yet, multiple factors impede the usefulness of WBE and quantitative adjustment may be required. Aim: We aimed to model the relationship between WBE data and incident COVID-19 cases, while adjusting for confounders and autocorrelation. Methods: This nationwide WBE study includes data from 40 wastewater treatment plants (WWTPs) in Belgium (02/2021–06/2022). We applied ARIMA-based modelling to assess the effect of daily flow rate, pepper mild mottle virus (PMMoV) concentration, a measure of human faeces in wastewater, and variants (alpha, delta, and omicron strains) on SARS-CoV-2 RNA levels in wastewater. Secondly, adjusted WBE metrics at different lag times were used to predict incident COVID-19 cases. Model selection was based on AICc minimization. Results: In 33/40 WWTPs, RNA levels were best explained by incident cases, flow rate, and PMMoV. Flow rate and PMMoV were associated with -13.0 % (95 % prediction interval: -26.1 to +0.2 %) and +13.0 % (95 % prediction interval: +5.1 to +21.0 %) change in RNA levels per SD increase, respectively. In 38/40 WWTPs, variants did not explain variability in RNA levels independent of cases. Furthermore, our study shows that RNA levels can lead incident cases by at least one week in 15/40 WWTPs. The median population size of leading WWTPs was 85.1 % larger than that of non‑leading WWTPs. In 17/40 WWTPs, however, RNA levels did not lead or explain incident cases in addition to autocorrelation. Conclusion: This study provides quantitative insights into key determinants of WBE, including the effects of wastewater flow rate, PMMoV, and variants. Substantial inter-WWTP variability was observed in terms of explaining incident cases. These findings are of practical importance to WBE practitioners and show that the early-warning potential of WBE is WWTP-specific and needs validation.
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This study presents the development of a SARS-CoV-2 detection method for domestic wastewater and river water in Costa Rica, a middle-income country in Central America. Over a three-year period (November to December 2020, July to N...
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This study presents the development of a SARS-CoV-2 detection method for domestic wastewater and river water in Costa Rica, a middle-income country in Central America. Over a three-year period (November to December 2020, July to November 2021, and June to October 2022), 80 composite wastewater samples (43 influent and 37 effluent) were collected from a Wastewater Treatment Plant (SJ-WWTP) located in San Jose, Costa Rica. Additionally, 36 river water samples were collected from the Torres River near the SJ-WWTP discharge site. A total of three protocols for SARS-CoV-2 viral concentration and RNA detection and quantification were analyzed. Two protocols using adsorption-elution with PEG precipitation (Protocol A and B, differing in the RNA extraction kit; n = 82) were used on wastewater samples frozen prior to concentration, while wastewater (n=34) collected in 2022 were immediately concentrated using PEG precipitation. The percent recovery of Bovine coronavirus (BCoV)was highest using the Zymo EnvironWaterRNA (ZEW) kitwith PEG precipitation executed on the same day as collection (mean 6.06%±1.37%). It was lowest when samples were frozen and thawed, and viruses were concentrated using adsorption-elution and PEG concentrationmethods using the PureLink™ Viral RNA/DNA Mini (PLV) kit (protocol A;mean 0.48%±0.23%). Peppermildmottle virus and Bovine coronavirus were used as process controls to understand the suitability and potential impact of viral recovery on the detection/quantification of SARS-CoV-2 RNA. Overall, SARS-CoV-2 RNA was detected in influent and effluent wastewater samples collected in 2022 but not in earlier years when the method was not optimized. The burden of SARS-CoV-2 at the SJ-WWTP decreased from week 36 to week 43 of 2022, coinciding with a decline in the national COVID-19 prevalence rate. Developing comprehensive nationwide surveillance programs for wastewaterbased epidemiology in low-middle-income countries involves significant technical and logistical challenges.
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