61 research outputs found
A transgenic approach to investigate the role of a mannose binding lectin gene on strawberry (Fragaria × ananassa) resistance to fungal pathogens
No full textWhite strawberry fruits (Fragaria ×ananassa) are more resistant to anthracnose disease caused by Colletotrichum spp. compared with red fruits. In white fruit infected with C. acutatum, a mannose binding lectin gene named FaMBL1 was found to be the most upregulated gene. In order to discern its role in strawberry resistance to C. acutatum, FaMBL1 silencing and overexpressing strawberry plants were generated through Agrobacterium tumefaciens transformation technique. Transformed strawberry lines were screened by selective media and specific amplicons via PCR. Copy number of target genes in the selected lines was determined by droplet digital PCR. Four overexpressing and three silencing lines, albeit with various copy number, were obtained. RT-PCR assay was conducted on different overexpressing lines, using RNA extracted from young leaves. The relative expressions of FaMBL1, some hormone-related-defence genes (FaAOS1, FaPAD4, FaEDS1, FaNCED1, FaZEP) and other defence-related genes (FaGSL5, FaPR1.2, FaWRKY1, FaPAL1) were quantified. The expression level of FaMBL1 gene in overexpression lines was significantly higher than wild type, while the difference for the defence-related genes was not that obvious. Interestingly, copy number of lectin transgene did not correlate with the level of expression of lectin gene in overexpressing lines
Exogenous dsRNAs against chitin synthase and glucan synthase genes suppress the virulence of the pathogenic fungus Botrytis cinerea
No full textBotrytis cinerea, the causative agent of the gray mold disease, causes crop failures of many economically important crops worldwide and its control is usually difficult. This study aims to evaluate the effectiveness of RNA interference (RNAi)-based control strategy to suppress the growth of B. cinerea, through exogenous application of double-strand RNA (dsRNA) targeting single and multiple genes encoding crucial enzymes for the fungal cell wall development. The dsRNA molecules were designed to target three single chitin synthase (BcCHSI, BcCHSIIIa, BcCHSVI) and two glucan synthase (alpha-1, 3-glucan synthase (Bcags), β-1, 3-glucan synthase (Bcbgs)), genes. Furthermore, two dsRNA chimeras targeting multiple Chitin synthase (BcCHSI/IIIa/VI) and Glucan synthase genes (Bcags/bgs) have been produced to inhibit Botrytis infection. Here we show that the dsRNAs treatments strongly affect the virulence of the fungus and result in the downregulation of BcCHSI, BcCHSIIIa, BcCHSVI, Bcags, and Bcbgs genes. Overall, our data indicate that exogenous application of dsRNAs can compromise the virulence of B. cinerea and that RNAi-based strategy targeting genes important for B. cinerea cell wall synthesis may provide an effective means to halt the growth of B. cinerea and consequently limit the infection
RNA Interference Strategies for Future Management of Plant Pathogenic Fungi: Prospects and Challenges
Get PDFPlant pathogenic fungi are the largest group of disease-causing agents on crop plants and represent a persistent and significant threat to agriculture worldwide. Conventional approaches based on the use of pesticides raise social concern for the impact on the environment and human health and alternative control methods are urgently needed. The rapid improvement and extensive implementation of RNA interference (RNAi) technology for various model and non-model organisms has provided the initial framework to adapt this post-transcriptional gene silencing technology for the management of fungal pathogens. Recent studies showed that the exogenous application of double-stranded RNA (dsRNA) molecules on plants targeting fungal growth and virulence-related genes provided disease attenuation of pathogens like Botrytis cinerea, Sclerotinia sclerotiorum and Fusarium graminearum in different hosts. Such results highlight that the exogenous RNAi holds great potential for RNAi-mediated plant pathogenic fungal disease control. Production of dsRNA can be possible by using either in-vitro or in-vivo synthesis. In this review, we describe exogenous RNAi involved in plant pathogenic fungi and discuss dsRNA production, formulation, and RNAi delivery methods. Potential challenges that are faced while developing a RNAi strategy for fungal pathogens, such as off-target and epigenetic effects, with their possible solutions are also discussed
Double-Stranded RNA Targeting Dicer-Like Genes Compromises the Pathogenicity of Plasmopara viticola on Grapevine
Get PDFDowny mildew caused by Plasmopara viticola is one of the most devastating diseases of grapevine, attacking all green parts of the plant. The damage is severe when the infection at flowering stage is left uncontrolled. P. viticola management consumes a significant amount of classical pesticides applied in vineyards, requiring efficient and environmentally safe disease management options. Spray-induced gene silencing (SIGS), through the application of exogenous double-stranded RNA (dsRNA), has shown promising results for the management of diseases in crops. Here, we developed and tested the potential of dsRNA targeting P. viticola Dicer-like (DCL) genes for SIGS-based crop protection strategy. The exogenous application of PvDCL1/2 dsRNA, a chimera of PvDCL1 and PvDCL2, highly affected the virulence of P. viticola. The reduced expression level of PvDCL1 and PvDCL2 transcripts in infected leaves, treated with PvDCL1/2 dsRNA, was an indication of an active RNA interference mechanism inside the pathogen to compromise its virulence. Besides the protective property, the PvDCL1/2 dsRNA also exhibited a curative role by reducing the disease progress rate of already established infection. Our data provide a promising future for PvDCL1/2 dsRNA as a new generation of RNA-based resistant plants or RNA-based agrochemical for the management of downy mildew disease in grapevine
A tradition in transition: Water management reforms and indigenous spate irrigation systems in Eritrea
No full textHas the pandemic become an excuse for curbing visitors from the Global South?
No full textRestrictive policies introduced to contain the spread of Covid-19 may now be conveniently applied to contain mobility from the global south to the global north. These Covid-19-related restrictions should have been reviewed pari passu with vaccination and infection rates, and with other mechanisms employed to slow down the spread of the virus. However, in many countries, the revision of laws and policies still lags. Guardian columnist and author Nesrine Malik succinctly encapsulates this emerging trend in her recent piece: “It’s hard to shake the impression that there is a desire not to return to normal rates of ebb and flow, but to use this opportunity to make it permanently harder to move around, particularly if your starting point is in the global south.
Characterization of Oral Cavity Lesions Within Betel Nut Users in Remote Pacific Islands
No full textThe general metadata -- e.g., title, author, abstract, subject headings, etc. -- is publicly available, but access to the submitted files is restricted to UT Southwestern campus access and/or authorized UT Southwestern users.This thesis includes 2 separate documents: [Part One] Efficacy and safety of artemether-lumefantrine to treat uncomplicated Plasmodium falciparum after a decade of its use as first-line antimalarial treatment in Namibia and [Part Two] Characterization of oral cavity lesions within betel nut users in remote Pacific Islands.Pages 1-30 are misnumbered as pages 2-31.[Efficacy and Safety of Artemether-lumefantrine to Treat Uncomplicated Plasmodium falciparum After a Decade of its Use As First-Tine Antimalarial Treatment In Namibia]
BACKGROUND: Artemether-lumefantrine (AL) has been the first-line treatment against uncomplicated Plasmodium falciparum malaria in Namibia since 2005. The World Health Organization regularly monitors and recommends antimalarial drugs in order to contain the rapid spread of the disease and for the early detection of drug resistant strains of the parasite.
AIM: The objective of this study is to assess the efficacy of AL in a low-transmission setting in Namibia.
METHODS: The study is conducted in the Zambezi region of Namibia and is a secondary analysis of a prior longitudinal cohort study. Symptomatic patients reporting to health facilities that were tested positive on the rapid diagnostic test were included in the study. A total of 44 patients were observed and given a 3-day course of AL and single low dose of primaquine as recommended by the WHO.
RESULTS: At Day 7, 100% of the patients had successfully cleared the infection. 95% of the participants had an adequate clinical and parasitological response with 2 patients presenting febrile at a follow-up visit classifying them as having late clinical failure.
CONCLUSION: Overall there were no apparent signs of drug resistance and AL was shown to be safe as a first-line antimalarial drug choice in a low-transmission setting for the treatment of uncomplicated P. falciparum malaria.[Characterization of Oral Cavity Lesions Within Betel Nut Users in Remote Pacific Islands]
BACKGROUND: Betel nut is a commonly chewed substance by the residents of Saipan and many other islands in the Western Pacific Ocean. 43% of Asian Pacific Islander adults in Saipan chew betel nut and 13% of cancer-related mortality in this region is due to oral cavity lesions.
AIM: The purpose of this study is to further characterize the types of oral cavity cancers that occur due to chewing betel nut and better understand best methods of treatment and prevention.
METHODS: A single-institution retrospective review was undertaken for 81 patients who were treated for primary cancers of the head and neck region at the Commonwealth Healthcare Corporation (CHC) in Saipan, CNMI between 2005 and 2019. Biopsies of the oral cavity lesions were obtained from the patients in Saipan and analyzed for further workup.
RESULTS: A majority of head and neck cancer patients had oral cavity cancer (64/81, 79.0%). Preliminary biopsy results show a high incidence of squamous cell carcinoma with squamous hyperplasia. A particularly high incidence of rare verrucous carcinoma was found (8/55, 14.5%).
CONCLUSIONS: Patients with the uncommon verrucous carcinoma should be treated differently as surgical outcomes differ in comparison to oral squamous cell carcinoma. Surgical resection in comparison to radiation therapy has been shown to have a good prognosis in patients with oral verrucous carcinoma. Further studies should be conducted to best prevent and treat these oral lesions
FLOWER BUD REMOVAL AND EARTHING UP TIME INCREASED GROWTH AND TUBER YIELD OF POTATO AT EASTERN TIGRAY, ETHIOPIA
Get PDFIn Ethiopia, potato is a staple food crop and source of cash income for smallholder farmers, but the national average yield in farmers’ field is lower than experimental yields due to poor agronomic activities. The study aimed to determine the effects of flower removal and earthing up time on growth and tuber yield of potato. The experiment comprised of three flower removal stage and five earthing up time treatments, which were laid out in a randomized complete block design of 3x5 factorial arrangements with three replications. Results indicated that plant height, stem number, tuber length and tuber diameter were shown significantly affected (p < 0.05) by the main effect of flower removal and earthing up time but not by their interaction. Fresh shoot biomass and physiological maturity were recorded significantly affected (p < 0.05) by earthing up time, but not by flower removal stage and its interaction with earthing up time. Total fresh biomass, marketable and unmarketable tuber yield, as well as total tuber yield were significantly affected (p < 0.05) by main factors and their interaction effects. The results clearly indicated that the highest total tuber yield (30.96 ton ha-1) was recorded from flower bud removed potato earthed up at 15 days after complete emergence. Therefore, flower bud removed potato earthed up at 15 days after full emergence was better in terms of all yield contributing characters and tuber yield
Cluster-based identification algorithm for in-line recycled concrete aggregates characterization using Laser-Induced Breakdown Spectroscopy (LIBS)
No full textTo upcycle End-of-Life (EoL) concrete from demolished buildings, it is essential to efficiently identify the different materials that may contaminate it. The precise identification and classification of materials and contaminants are vital processes for in-line quality inspection of recycled concrete aggregates transported on a conveyor belt. In this study, a total of eight potential contaminants are considered as target contaminant materials in the streams made of coarse and fine aggregates resulting from the upcycling of EoL concrete. These contaminants degrade the quality of the aggregates even at low concentrations, so it is essential to identify the presence of such contaminants along with the main products of recycling which are recycled coarse aggregates (RCA) and recycled fine aggregates (RFA). An efficient method is proposed to identify and classify EoL concrete waste along with RCA and RFA in motion on conveyor belts via laser-induced breakdown spectroscopy (LIBS) coupled with a cluster-based identification algorithm. The model is verified with an accuracy of 0.97, a precision (weighted average) of 0.98, a recall (weighted average) of 0.97, and an F1-score (weighted average) of 0.98 for the validation set, under the optimal conditions. This study suggests that LIBS may be well suited for fast and in-line analysis of recycled concrete aggregates in industrial applications. This approach presents an innovative approach for the quality characterization of secondary materials produced from EoL concrete being transported on conveyor belts, and therefore can be of great value for the processing and high-end utilization of EoL concrete.Resources & Recyclin
Assessment of In-Person and Cyber Aggression and Victimization, Substance Use, and Delinquent Behavior During Early Adolescence
No full text© The Author(s) 2018. This study evaluated the Problem Behavior Frequency Scale–Adolescent Report (PBFS-AR), a measure designed to assess adolescents’ frequency of victimization, aggression, substance use, and delinquent behavior. Participants were 1,263 students (50% female; 78% African American, 18% Latino) from three urban middle schools in the United States. Confirmatory factor analyses of competing models of the structure of the PBFS-AR supported a model that differentiated among three forms of aggression (in-person physical, in-person relational, and cyber), two forms of victimization (in-person and cyber), substance use, and delinquent behavior. This seven-factor model fit the data well and demonstrated strong measurement invariance across groups that differed on sex and grade. Support was found for concurrent validity of the PBFS-AR based on its pattern of relations with school office discipline referrals
- …
