Important result from Universita 'della Tuscia, Italy
Advanced molecular technique developed to identify PSA
Having previously clarified by a detailed research regarding the genome of the major PSA world populations (dx.plos.org/10.1371/journal.pone.0036518) on the origin of the pathogen while at the beginning of the bacterial outbreak, Italy was wrongly suspected, and have also highlighted the infection strategies adopted by this bacterium to attack and to move within the plant Actinidia spp. (see previous article), the same research group, in collaboration with the research team of Prof. Vinatzer of Dep. of Plant Pathology at Virginia Tech University, USA, has recently developed a novel technique of molecular biology to identify Psa.
This week was in fact published in the international scientific journal Plant Disease (Vol. 97, No. 4, p. 472-478) Authors: Balestra, G. M., Taratufolo, M. C., Vinatzer, B. A., and Mazzaglia, A. research titled (click here to enlarge):
Until now, no system for the identification of Pseudomonas syringae pv. actinidiae (PSA) made it possible to provide a complete selectivity for this pathovar and simultaneously discriminate between its different haplotypes. Therefore, this aspect has worked and has been developed and validated a new system using multiplex PCR (m-PCR).
The assay was tested on 32 known Psa isolates and 15 do not belong to Psa. Known Psa isolates were divided into three different haplotypes: a Japanese/Korean, a European and a Chinese group; 2 isolates of NZ PSA have been associated with those pertaining to Chinese group, while the other two NZ PSA isolates and isolated from kiwi plants but does not cause canker, were negative.
The m-PCR assay described is capable of detect the pathogen even when this is present in very small quantities (up to 5-50 pg of bacterial DNA purified or 5 × 102 bacterial cells) and is effective on both naturally infected plant tissues, that of those infected artificially. This method is therefore a suitable instrument to simultaneously detect P. syringae pv. actinidiae and the recognition of its haplotype geographical origin, in particular, the method is particularly suitable when it is requested to analyze large quantities of samples (adult plants, nursery plants) during the surveillance and prevention.
The method described is an innovative tool for the detection/identification of PSA and is especially practical to verify the geographical origin of the pathogen. By virtue of the results obtained the same methodology is therefore particularly useful to test large numbers of samples where, however vegetable asymptomatic PSA may be present, and therefore of particular applicability during the surveillance, monitoring and prevention, such as the National/Regional Plant Protection Service as other technical services in charge.
Further info:
Dr. Giorgio M. Balestra - Ricercatore
DAFNE (Dipartimento di scienze e tecnologie per l'Agricoltura, le Foreste, la Natura e l'Energia) - Università della Tuscia
Via S. Camillo de Lellis
01100 Viterbo - Italy
Ph.: +39 0761 357474
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Email: balestra@unitus.it
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