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Posted 30 January 2019. PMN Crop News.


Agdia Launches Rapid Molecular Assay to Detect Dickeya spp. Causing Blackleg Disease on Potato


Source: Agdia Press Release. http://www.agdia.com


Elkhart, Indiana (January 14, 2019)--Agdia, Inc. has commercialized a rapid, user-friendly molecular assay, on their AmplifyRP® XRT+ platform, for the detection of Dickeya spp. causing blackleg disease on potato.

 

Dickeya spp. of bacteria are responsible for numerous plant diseases worldwide, including blackleg disease on potato. The species of bacteria in this genus produce pectolytic enzymes that degrade plant cell walls, liquifying pectin and causing tissue death. Tissue maceration causes the characteristic symptoms of stem necrosis or blackleg on aerial plant parts (Figure 1.) and wilting (Figure 2.). Dickeya spp. are disseminated primarily on latently infected seed tubers; infection courts include tuber surface, the lenticels, and/or the vascular system of the tuber. This group of pathogens is economically-important and has been responsible for significant crop losses in North America and Europe.


 

Figure 1. Blackleg symptoms on potato. (Image courtesy of Amy Charkowski, Colorado State University.)

 


 

Figure 2. Wilting of potato plant infected with Dickeya. (Image courtesy of Amy Charkowski, Colorado State University.)

 

The AmplifyRP® XRT+ assay for detection of Dickeya spp. is an isothermal amplification technology that implements the recombinase polymerase amplification (RPA) platform. This method promotes the rapid amplification and detection of nucleic acid targets (DNA or RNA), via enzymatic reactions, and maintains a single operating temperature of 39oC. The RPA technology provides comparable sensitivity and specificity to polymerase chain reaction (PCR) assays while offering advantages to PCR. Crude plant extracts are processed for RPA and total assay time is approximately 30-40 minutes, including sample preparation.* Results can be visualized in quantitative, real-time format using Agdia’s AmpliFire® portable fluorometer or as end-point detection in an amplicon detection chamber. Furthermore, RPA does not require expertise in molecular diagnostics to perform.

*Approximately 20 minutes run-time in fluorometer and 40 minutes run-time in heat block and amplicon detection chamber.

Agdia states their new assay will detect all species of Dickeya known to be pathogenic on potato, including D. dianthicola and D. solani. Furthermore, no cross-reactivity was observed with several potential cross-reactors, including Pectobacterium spp., Erwinia spp., Clavibacter michiganensis subsp. sepedonicus, Ralstonia solanacearum, Candidatus Liberibacter solanacearum, Fusarium spp., and Phytophthora spp. Agdia states their RPA assay for the detection of Dickeya is comparable or superior to all available molecular and serological diagnostics, in sensitivity and specificity. This assay will detect Dickeya spp. in tubers, stem tissue, and pure cultures. The introduction of this RPA assay is the third in the last 12 months for Agdia, bringing their total catalog to 13 assays on this platform.

Agdia recommends using the AmpliFire® portable fluorometer (figure 3.) or the amplicon detection chamber (figure 4.) with their AmplifyRP® XRT+ products. The AmpliFire® is battery-operated and portable, allowing it to be implemented in remote locations. A large, intuitive touchscreen makes workflow simple and straightforward while data export options provide for detailed interface with personal computers. The amplicon detection chamber is used in conjunction with a heat block to visualize end-point results. The lateral flow strip inside the chamber detects dual labeled amplicons, both DNA and RNA. Amplicon detection chambers are designed to provide reliable amplicon detection while preventing escape and contamination of future assays. The chambers are for single use only. For more information on Agdia’s complete line of AmplifyRP® assays, please visit Agdia’s website.



 

Figure 3. Results displayed on Agdia AmpliFire®.

 


 

Figure 4. Results displayed in Agdia amplicon detection chamber.

 

About Agdia

A leading provider of diagnostic solutions for agriculture, Agdia, Inc. has been serving plant breeders, propagators, growers, universities, and private testing laboratories since 1981. The company offers a comprehensive portfolio of validated, easy-to-use diagnostics for identifying plant pathogens, hormones, and transgenic traits. In addition, Agdia operates an ISO accredited, in-house, testing services laboratory. Agdia’s quality management system is ISO 9001:2015 certified and their Testing Services Laboratory is ISO 17025:2005 accredited. Visit the company’s website at www.agdia.com, e-mail info@agdia.com, phone 1-574-264-2615 (toll-free 800-622-4342) or fax 1-574-264-2153.


About AmplifyRP®

AmplifyRP XRT Test Kits employ recombinase polymerase amplification (RPA) technology licensed by Agdia, Inc (licensee) from TwistDx Limited, U.K. (licensor). Use of the RPA process and probe technologies are protected by US patents 7,270,981 B2, 7,399,590 B2, 7,435,561 B2, 7,485,428 B2 and foreign equivalents in addition to pending patents.

AmplifyRP® and AmpliFire® are registered trademarks of Agdia, Inc.