|KALUZNA, MONIKA - Research Institute Of Horticulture|
|PROKIC, ANDJELKA - University Of Belgrade|
|OBRADOVIC, ALEKSA - University Of Belgrade|
|WELDON, WILLIAM - Valent Biosciences-Usa|
|POTHIER, JOËL - Zurich University Of Applied Sciences|
Submitted to: Frontiers in Plant Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/18/2023
Publication Date: 9/13/2023
Citation: Stockwell, V.O., Kaluzna, M., Prokic, A., Obradovic, A., Pothier, J., Weldon, W. 2023. Specific and sensitive detection tools for Xanthomonas arboricola pv. corylina, the causal agent of bacterial blight of hazelnut, developed with comparative genomics. Frontiers in Plant Science. 14:1254107. https://doi.org/10.3389/fpls.2023.1254107.
Interpretive Summary: Detecting pathogens in plant tissues using traditional isolation and identification methods often takes several weeks. PCR (polymerase chain reaction) assays are used in plant disease clinics and quarantine services to quickly detect and identify many plant pathogens. Unfortunately, PCR assays to distinguish closely-related bacterial pathogens have been elusive. For example, current PCR assays cannot distinguish Xanthomonas arboricola pathovar corylina (Xac), a regulated pathogen of hazelnut trees in Europe, and non-regulated pathovars of X. arboricola. Our international research team compared whole genome sequences of Xac to its close relatives and found a unique region. We designed PCR assays for Xac and verified their fidelity to the pathogen. The new PCR-based detection and identification assays will enable plant disease clinics and research laboratories to detect and identify Xac in a matter of hours. This research shows the value of whole genome sequences for the design of new methods to monitor plant pathogens. These specific, rapid, and accurate detection methods for Xac will be integral for disease diagnosis and for ensuring that hazelnut plants in nurseries or international trade do not harbor the pathogen.
Technical Abstract: Specific primer pairs were designed to detect the causal agent of bacterial blight of hazelnut, Xanthomonas arboricola pv. corylina (Xac), a regulated quarantine bacterium in Europe. A comparative genomics approach was used with publicly available genomes of Xac to select unique targets to design identification and detection systems using conventional PCR, qPCR (SYBR Green and TaqMan), and loop-mediated isothermal amplification (LAMP). All assays performed on genomic DNA isolated from all eight X. arboricola pathovars and closely related bacterial species confirmed the specificity of selected primers. Moreover, these assays enabled accurate detection of Xac in pure cultures and plant tissues. These new diagnostic tools rapidly and accurately distinguished bacteria in symptomatic hazelnut tissues and pure cultures of Xac from closely related pathovars of X. arboricola.