Systemic colonization of potato plants resulting from potato haulm inoculation with Dickeya solani or Pectobacterium parmentieri

Abstract

In two glasshouse experiments, colonization of potato (Solanum tuberosum L.) plants by the bacterial pathogens Dickeya solani and Pectobacterium parmentieri was studied after leaf infection. Leaves, whether or not artificially wounded, were spray-inoculated with various densities of green-fluorescent protein tagged strains of the pathogens, avoiding contamination of soil during inoculation. Microscopy analysis indicated that both pathogens were able to penetrate and colonize hydathodes, stomata and wounds of inoculated leaves. Dickeya solani was detected at 42 days after inoculation in leaves, stems, stolons and occasionally in tubers, whereas P. parmentieri was restricted to leaves, stems and stolons, and could not be detected in tubers. The infection percentage was higher for plants with wounded leaves than for plants with untouched leaves, and higher at higher inoculum densities. Nevertheless, infection of leaves could also occur at low densities of D. solani (10 2 cfu mL −1). We further investigated the risks for translocation of the pathogens from infected haulms through soil into progeny tubers after haulm destruction. In a glasshouse experiment, populations of the pathogens increased in haulms in the first week after chemical or mechanical destruction, but decreased in the second week. For P. parmentieri, transmission occurred from destroyed haulms via soil into progeny tubers in soil, but not for D. solani.

Pectobacterium parmentieri SCC 3193 Mutants with Altered Synthesis of Cell Surface Polysaccharides Are Resistant to N4-Like Lytic Bacteriophage ϕA38 (vB_Ppp_A38) but Express Decreased Virulence in Potato (Solanum tuberosum L.) Plants

“…Together with other SRP species causing diseases of crops, P. parmentieri (formerly known as Erwinia carotovora subsp. wasabiae and later P. wasabiae ) has recently been recognized as an increasing threat for potato cultivation [ 6 , 7 , 8 ]. This species was first described as a pathogen in 2010, causing severe potato blackleg outbreaks in field-grown crops in New Zealand [ 9 ].…”

“…Due to the development of new genome-based taxonomic classification techniques, it has become evident that many bacteria previously characterized as Pectobacterium carotovorum that were isolated from crops in Europe and elsewhere should be currently re-classified as P. parmentieri [ 11 ]. In the last ten years, the dominant role of P. parmentieri in the epidemiology of potato blackleg and soft rot diseases in Europe and worldwide has been widely recognized [ 8 ].…”

Biosensors Used for Epifluorescence and Confocal Laser Scanning Microscopies to Study Dickeya and Pectobacterium Virulence and Biocontrol

“…The obtained results suggested that D. solani colonizes potato and S. dulcamara plants in a very similar manner, as it was evidenced after infection that the bacteria used vascular tissue to systemically spread inside both plant species and cause visually similar symptoms in culture-tube grown plants [ 107 ]. Recently, Kastelein et al [ 104 ] assessed the spread of GFP-tagged D. solani and Pectobacterium parmentieri strains inside potato plants after spray-inoculation of wounded and intact potato leaves. The GFP-tagged bacteria belonging to both species were detected in distantly located plant parts, indicating that upon favorable conditions, the SRP bacteria can probably pose a risk for the next generation of crop cultivation [ 104 ].…”

“…Recently, Kastelein et al [ 104 ] assessed the spread of GFP-tagged D. solani and Pectobacterium parmentieri strains inside potato plants after spray-inoculation of wounded and intact potato leaves. The GFP-tagged bacteria belonging to both species were detected in distantly located plant parts, indicating that upon favorable conditions, the SRP bacteria can probably pose a risk for the next generation of crop cultivation [ 104 ]. In the aforementioned studies, GFP tagging was done to support the observations on the spread of bacterial pathogens in host plants.…”

Die-off of plant pathogenic bacteria in tile drainage and anoxic water from a managed aquifer recharge site

“…In some studies, disease outbreaks were related to the usage of contaminated irrigation water [ 17 ]. Kastelein et al [ 18 ] reported that spray inoculation of potato leaves with 10 2 CFU/mL D . solani resulted in diseased plants in greenhouse experiments.…”