scholarly journals qPCR and loop mediated isothermal amplification for rapid detection of Ustilago tritici

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7766 ◽  
Author(s):  
Hanwen Yan ◽  
Jian Zhang ◽  
Dongfang Ma ◽  
Junliang Yin

Loose smut of wheat caused by the basidiomycete fungus Ustilago tritici, a seed-borne disease, is difficult to control because of the expanse of wheat planting area and difficulty in pathogen detection. In this study, real-time fluorescence quantitative PCR (qPCR) and loop-mediated isothermal amplification (LAMP) assays are used to rapidly amplify the DNA of U. tritici. Five pairs of primers for qPCR and two series primers for LAMP were designed. Primarily, the specificity of the primer was assessed by using genomic DNA of U. tritici, Fusarium graminearum, Blumeria graminis, Rhizoctonia cerealis, Puccinia striiformis, Bipolaris sorokiniana, and Alternaria solani as templates. Further, the amplification systems were optimized. Finally, the sensitivity of qPCR and LAMP assays were evaluated. The results showed that the primer Y-430 F/R, Y-307 F/R, Y-755 F/R, and Y-139 F/R for qPCR and primers L-139 and L-988 for LAMP could be used for U. tritici detection. In the sensitivity test, the detection limit of qPCR assay was identified as 10 pg μL−1 of genomic DNA, the detection limit for LAMP assay was 100 fg μL−1. We successfully performed qPCR and LAMP assays on wheat loose smut wheat samples. This paper establishes two methods for U. tritici detection, which can be used for diagnosis of wheat loose smut in the laboratory and in the field.

2019 ◽  
Author(s):  
Hanwen Yan ◽  
Jian Zhang ◽  
Dongfang Ma ◽  
Junliang Yin

Wheat loose smut caused by Ustilago tritici a seed-borne disease, is difficult to control due to the expansion of wheat planting area and difficulty of pathogen detection. In this study, real-time fluorescence quantitative PCR (qPCR) and loop-mediated isothermal amplification (LAMP) assays were used to rapidly amplify the DNA of U. tritici. Five pairs primers for qPCR and two series primers for LAMP were designed. Firstly, the specify of primers were carried out by using the DNAs of U. tritici, Fusarium graminearum, Blumeria graminis, Rhizoctonia cerealis, Puccinia striiformis, Bipolaris sorokiniana, and Alternaria solani as templates. Then the amplification systems are optimized. Finally, the sensitivity of qPCR and LAMP assays were quantified. The results show that using the primers pairs Y430F/R, Y307F/R, Y755F/R and Y139F/R for qPCR, primers L-139 and L-988 for LAMP assay could be used for U. tritici detection. In the sensitivity test, the detection limit of qPCR assay is 10 pg μL-1 of genomic DNA, the detection limit of LAMP assay is 100 fg μL -1 . We successfully performed qPCR and LAMP assays on two wheat loose smut wheat samples, and confirmed sequenced U. tritici infection by subsequently sequencing. This paper established two methods for U. tritici detection, which could be used for wheat loose smut diagnose in lab and field.


2019 ◽  
Author(s):  
Hanwen Yan ◽  
Jian Zhang ◽  
Dongfang Ma ◽  
Junliang Yin

Wheat loose smut caused by Ustilago tritici a seed-borne disease, is difficult to control due to the expansion of wheat planting area and difficulty of pathogen detection. In this study, real-time fluorescence quantitative PCR (qPCR) and loop-mediated isothermal amplification (LAMP) assays were used to rapidly amplify the DNA of U. tritici. Five pairs primers for qPCR and two series primers for LAMP were designed. Firstly, the specify of primers were carried out by using the DNAs of U. tritici, Fusarium graminearum, Blumeria graminis, Rhizoctonia cerealis, Puccinia striiformis, Bipolaris sorokiniana, and Alternaria solani as templates. Then the amplification systems are optimized. Finally, the sensitivity of qPCR and LAMP assays were quantified. The results show that using the primers pairs Y430F/R, Y307F/R, Y755F/R and Y139F/R for qPCR, primers L-139 and L-988 for LAMP assay could be used for U. tritici detection. In the sensitivity test, the detection limit of qPCR assay is 10 pg μL-1 of genomic DNA, the detection limit of LAMP assay is 100 fg μL -1 . We successfully performed qPCR and LAMP assays on two wheat loose smut wheat samples, and confirmed sequenced U. tritici infection by subsequently sequencing. This paper established two methods for U. tritici detection, which could be used for wheat loose smut diagnose in lab and field.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Somayyeh Sedaghatjoo ◽  
Monika K. Forster ◽  
Ludwig Niessen ◽  
Petr Karlovsky ◽  
Berta Killermann ◽  
...  

AbstractTilletia controversa causing dwarf bunt of wheat is a quarantine pathogen in several countries. Therefore, its specific detection is of great phytosanitary importance. Genomic regions routinely used for phylogenetic inferences lack suitable polymorphisms for the development of species-specific markers. We therefore compared 21 genomes of six Tilletia species to identify DNA regions that were unique and conserved in all T. controversa isolates and had no or limited homology to other Tilletia species. A loop-mediated isothermal amplification (LAMP) assay for T. controversa was developed based on one of these DNA regions. The specificity of the assay was verified using 223 fungal samples comprising 43 fungal species including 11 Tilletia species, in particular 39 specimens of T. controversa, 92 of T. caries and 40 of T. laevis, respectively. The assay specifically amplified genomic DNA of T. controversa from pure cultures and teliospores. Only Tilletia trabutii generated false positive signals. The detection limit of the LAMP assay was 5 pg of genomic DNA per reaction. A test performance study that included five laboratories in Germany resulted in 100% sensitivity and 97.7% specificity of the assay. Genomic regions, specific to common bunt (Tilletia caries and Tilletia laevis together) are also provided.


Plant Disease ◽  
2021 ◽  
Author(s):  
Xiayan Pan ◽  
Xiao Wang ◽  
Junjie Yu ◽  
Mina Yu ◽  
Huijuan Cao ◽  
...  

Rice false smut (RFS), caused by Villosiclava virens, is an important fungal disease in panicle of rice. V. virens is a heterothallic ascomycete that controlled by two opposite idiomorphs, MAT1-1 and MAT1-2. Previous study showed sexual reproduction of V. virens plays an important role in the epidemic of RFS. In this study, we have developed a loop-mediated isothermal amplification (LAMP) assay to detect mating type of V. virens easily and rapidly by using specific primers designed on the mating type genes MAT1-1-2 and MAT1-2-1, respectively. The LAMP assay required only a water/dry bath and could recognize the mating type of V. virens in just 45 min. The LAMP assay was so sensitive that could detect small amounts of V. virens genomic DNA (as low as 2.0 pg of MAT1-1, and 200.0 pg of MAT1-2), which was 10-fold more sensitive than polymerase chain reaction (PCR). In addition, the application of mating type using LAMP assay was demonstrated feasibly by assessing the genomic DNA of V. virens isolated from rice fields. The high efficiency and specificity of this LAMP assay suggested it can be used as a rapid testing tool in mating type recognition of V. virens isolates in the field.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Xuzhi Zhang ◽  
Qianqian Yang ◽  
Qingli Zhang ◽  
Xiaoyu Jiang ◽  
Xiaochun Wang ◽  
...  

Abstract The cytochrome cd1-containing nitrite reductase, nirS, plays an important role in biological denitrification. Consequently, investigating the presence and abundance of nirS is a commonly used approach to understand the distribution and potential activity of denitrifying bacteria, in addition to denitrifier communities. Herein, a rapid method for detecting nirS gene with loop-mediated isothermal amplification (LAMP) was developed, using Pseudomonas aeruginosa PAO1 (P. aeruginosa PAO1) as model microorganism to optimize the assay. The LAMP assay relied on a set of four primers that were designed to recognize six target sequence sites, resulting in high target specificity. The limit of detection for the LAMP assay under optimized conditions was 1.87 pg/reaction of genomic DNA, which was an order of magnitude lower than that required by conventional PCR assays. Moreover, it was validated that P. aeruginosa PAO1 cells as well as genomic DNA could be directly used as template. Only 1 h was needed from the addition of bacterial cells to the reaction to the verification of amplification success. The nirS gene of P. aeruginosa PAO1 in spiked seawater samples could be detected with both DNA-template based LAMP assay and cell-template based LAMP assay, demonstrating the practicality of in-field use.


Plant Disease ◽  
2011 ◽  
Vol 95 (4) ◽  
pp. 423-430 ◽  
Author(s):  
Todd N. Temple ◽  
Kenneth B. Johnson

Fire blight of pear and apple is frequently an inoculum-limited disease but weather-based forecasting models commonly assume that the pathogen is omnipresent. To improve fire blight risk assessment during flowering, we developed a rapid pathogen detection protocol that uses loop-mediated isothermal amplification (LAMP) to detect DNA of epiphytic Erwinia amylovora on samples of pear and apple flowers. LAMP detected a single flower colonized epiphytically by E. amylovora in a sample of 100 flower clusters (approximately 600 flowers). Samples of 100 flower clusters from orchards (approximately one sample per hectare) were washed and subjected to LAMP, which was completed in 2 h. In three experimental orchards inoculated with E. amylovora, positive LAMP reactions were attained from nine of nine 100-flower cluster samples; pathogen populations in the floral washes averaged 5.2 × 103 CFU per flower as determined by dilution plating. Samples of pear and apple flowers obtained from 60 commercial orchards located in Oregon, Washington, California, and Utah resulted in detection of E. amylovora by LAMP assay from 34 sites, 20 of which developed fire blight. Of samples at early bloom, 10% were positive for epiphytic E. amylovora compared with 28% at petal fall; pathogen density in washes of positive samples averaged 3.2 × 102 CFU per flower. In another 26 orchards, all floral washes were negative for E. amylovora by LAMP and by dilution plating; a light severity of fire blight was observed in 8 of these orchards. Overall, positive detection of epiphytic E. amylovora in commercial orchards by LAMP-based scouting generally occurred at later stages of bloom after heat (risk) units had begun to accumulate, an indication that weather-based forecasting models may be an adequate measure of fire blight risk for many orchardists. Nonetheless, several orchardists communicated that information from the LAMP-based rapid detection protocol resulted in modification of their fire blight management practices.


2018 ◽  
Author(s):  
Qianqian Yang ◽  
Xuzhi Zhang ◽  
Xiaoyu Jiang ◽  
Xiaochun Wang ◽  
Yang Li ◽  
...  

AbstractThe cytochromecd1-containing nitrite reductase,nirS, plays an important role in biological denitrification. Consequently, investigating the presence and abundance ofnirSis a commonly used approach to understand the distribution and potential activity of denitrifying bacteria, in addition to denitrifier communities. Herein, a new molecular biology technique termed loop-mediated isothermal amplification (LAMP) was developed to rapidly detectnirSgene using those ofPseudomonas aeruginosato optimize the assay. The LAMP assay relied on a set of four primers that were designed to recognize six target sequence sites, resulting in high target specificity. The specificity of the assay was confirmed by the lack of amplification when using DNA from 15 other bacterial species lackingnirSgene. The limit of detection for the LAMP assay under optimized conditions was 1.87 pg/reaction of genomic DNA, which was an order of magnitude lower than that required by conventional PCR assays. Moreover, a cell-template based LAMP assay was also developed for detectingnirSgene that directly used bacterial cells as template rather than genomic DNA. Only 1 h was needed from the addition of bacterial cells to the reaction to the verification of amplification success, and bulky and sophisticated equipment were not needed. Further, thenirSgene ofP. aeruginosain spiked seawater samples could be detected with both the DNA-template based LAMP assay and the cell-template based LAMP assay, thereby demonstrating the practicality of in-field use of them. In summary, the LAMP assays described here represent a rapid, user-friendly, and cost-effective alternative to conventional PCR.


PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4639 ◽  
Author(s):  
Lindsey D. Thiessen ◽  
Tara M. Neill ◽  
Walter F. Mahaffee

Plant pathogen detection systems have been useful tools to monitor inoculum presence and initiate management schedules. More recently, a loop-mediated isothermal amplification (LAMP) assay was successfully designed for field use in the grape powdery mildew pathosystem; however, false negatives or false positives were prevalent in grower-conducted assays due to the difficulty in perceiving the magnesium pyrophosphate precipitate at low DNA concentrations. A quantitative LAMP (qLAMP) assay using a fluorescence resonance energy transfer-based probe was assessed by grape growers in the Willamette Valley of Oregon. Custom impaction spore samplers were placed at a research vineyard and six commercial vineyard locations, and were tested bi-weekly by the lab and by growers. Grower-conducted qLAMP assays used a beta-version of the Smart-DART handheld LAMP reaction devices (Diagenetix, Inc., Honolulu, HI, USA), connected to Android 4.4 enabled, Bluetooth-capable Nexus 7 tablets for output. Quantification by a quantitative PCR assay was assumed correct to compare the lab and grower qLAMP assay quantification. Growers were able to conduct and interpret qLAMP results; however, theErysiphe necatorinoculum quantification was unreliable using the beta-Smart-DART devices. The qLAMP assay developed was sensitive to one spore in early testing of the assay, but decreased to >20 spores by the end of the trial. The qLAMP assay is not likely a suitable management tool for grape powdery mildew due to losses in sensitivity and decreasing costs and portability for other, more reliable molecular tools.


2019 ◽  
Author(s):  
Aleksandra Anna Zasada ◽  
Aldona Wiatrzyk ◽  
Urszula Czajka ◽  
Klaudia Brodzik ◽  
Kamila Formińska ◽  
...  

Abstract Background Diphtheria outbreaks occurred in endemic areas and imported and indigenous cases are reported in UE/EEA. Because of the high infectiveness and severity of the disease, early and accurate diagnosis of each suspected case is essential for the treatment and management of the case and close contacts. The aim of the study was to establish simple and rapid testing methods based on Loop-Mediated Isothermal Amplification (LAMP) assay for the detection of Corynebacterium diphtheriae and differentiation between toxigenic and non-toxigenic strains.Methods Corynebacterium diphtheriae and Corynebacterium ulcerans isolates from the National Institute of Public Health-National Institute of Hygiene collection were used for the development of LAMP assay for the diagnosis of diphtheria and nontoxigenic C. diphtheriae infections. Various colorimetric methods for visualization of results were investigated. Sensitivity and specificity of the assay were examined using a collection of DNA samples from various gram-positive and gram-negative bacteria.Results The LAMP assay for tox and dtxR genes was developed. The sensitivity and specificity of the assay were calculated as 100%. The detection limit was estimated as 1.42 pg/µl concentration of DNA template when the reaction was conducted for 60 min. However, the detection limit was lowered 10 times for every 10 minutes of reduction in the time of incubation during the reaction. Positive results were successfully detected colorimetrically using hydroxynaphthol blue, calcein, QuantiFluor, and lateral flow Milenia HybriDetect dipsticks.Conclusion The assay developed in the study might be applied for point-of-care testing of diphtheria and other C. diphtheriae infections. It is highly sensitive, specific, inexpensive, easy to use, and suitable for low-resource settings.


Plant Disease ◽  
2019 ◽  
Vol 103 (12) ◽  
pp. 3002-3008 ◽  
Author(s):  
Xue Yang ◽  
Yong-Jie Qi ◽  
Mohamed N. Al-Attala ◽  
Zheng-Hui Gao ◽  
Xing-Kai Yi ◽  
...  

Alternaria species are the most important fungal pathogens that attack various crops as well as fruit trees such as pear and cause black spot disease. Here, a loop-mediated isothermal amplification (LAMP) assay is developed for the detection of Alternaria species. A. alternata cytochrome b (cyt-b) gene was used to design two pairs of primers and amplified a 229-bp segment of Aacyt-b gene. The results showed that LAMP assay is faster and simpler than polymerase chain reaction (PCR). LAMP assay is highly sensitive method for the detection of about 1 pg of genomic DNA of A. alternata by using optimized concentration of MgCl2(4 mM) in final LAMP reaction. In contrast, the limit of detection was 1 ng of target DNA via conventional PCR. Among the genomic DNA of 46 fungal species, only the tubes containing DNA of Alternaria spp. except A. porri, A. solani, and A. infectoria changed color from orange to yellowish green with SYBR Green I including the main pathogens of pear black spot. The yellowish green color was indicative of DNA amplification. Moreover, LAMP assay was used for testing infected tissues among 22 healthy and diseased pear tissues; the orange color changed to yellowish green for infected tissues only. Altogether, we conclude that cyt-b gene can be used for the detection of Alternaria spp. via LAMP assay, which is involved in pear black spot disease.


Sign in / Sign up

Export Citation Format

Share Document