The occurrence of bacteria from different species of Pectobacteriaceae on seed potato plantations in Poland

Abstract

Bacteria from the genera Dickeya and Pectobacterium, the causative agents of soft rot and blackleg, trigger significant economic losses in potato production worldwide. Efficient struggle with these phytopathogens is highly challenging taking into consideration the lack of available control procedures. As only preventive measures are accessible, we decided to provide insight into the soft rot Pectobacteriaceae (SRP) present in Poland. During the growing seasons of 2013 and 2014, altogether 531 potato plants were collected from 138 seed potato fields and 23 storage facilities. Plant origin of the isolated bacteria, frequencies of coinfections with different species, the affected potato cultivars in addition to seasonal variation in the occurrence of SRP were studied. It was shown that bacteria from the Pectobacterium genus were abundant and outnumbered the ones classified to Dickeya spp. The vast majority of strains was isolated from the plant samples collected in July 2013 or in June–July 2014. The presence of all taxa of interest: Pectobacterium atrosepticum, Pectobacterium carotovorum, Pectobacterium parmentieri, Dickeya dianthicola and Dickeya solani were confirmed in July each year. We were able to isolate bacteria from the genus Dickeya and Pectobacterium from 35 out of 58 potato cultivars tested. The majority of SRP was isolated from potato stems, not from potato tubers. In four cases, coinfections of potato samples with even three diverse species of SRP, i.e. P. atrosepticum, P. carotovorum and P. parmentieri, were noted. It seems that since the first documented appearance of Dickeya solani in Poland in 2005, this pathogen has not played a dominating role in our country. The reported data describing the appearance and distribution of SRP in Poland might allow for prediction of the risks associated with infections initiated by these bacteria.

Early Emergence of Dickeya solani Revealed by Analysis of Dickeya Diversity of Potato Blackleg and Soft Rot Causing Pathogens in Switzerland

“…Three of these strains cluster with Pectobacterium, the other genus grouping pectinolytic bacteria commonly involved in potato blackleg disease. These include two strains belonging to P. versatile, a species recently described to have a very broad host range [26] and one strain belonging to P. parmentieri, another recently described species that was, however, present in potatoes in Poland from the 1990s [27,28]. More unexpectedly, two strains closely cluster with Rahnella aquatilis, a gammaproteobacterium whose genus members have been isolated from soil, freshwater and food, but also clinical samples [29].…”

“…Average nucleotide identity (ANI) analysis revealed that these six strains are highly similar with ANI percentage between them, ranging from 99.96 to 100% with a high percentage of all compared genomes being successfully aligned (99.03 to 99.99%). As already described [28], we refined this analysis by mapping the Illumina reads of the four Swiss genomes to the 3337 complete genome, allowing us to identify SNPs and InDels variations. The four Swiss strains only exhibit 53 to 94 SNPs/InDels, among which 49 are common to the four Swiss strains, indicating they are specific to the 3337 genome (Table 3).…”

Interplay between Coumarin Accumulation, Iron Deficiency and Plant Resistance to Dickeya spp.

“…It should be also highlighted that most of the previously published data describe the interaction between Arabidopsis plants and D. dadantii 3937. According to our best knowledge D. solani , which is an important plant pathogenic bacterium causing a loss in potato yield in Europe [ 34 , 51 , 52 ] was not tested before with a model plant Arabidopsis. Moreover, recent results show that D. solani strains cause severe disease symptoms in temperate climates, and are more aggressive than other blackleg-causing bacteria from genus Dickeya and Pectobacterium spp.…”

The First Polish Isolate of a Novel Species Pectobacterium aquaticum Originates from a Pomeranian Lake

“…Members of this genus joined the newly established Pectobacteriaceae family [ 2 ] due to the fact of their genomic characteristics and their ability to produce pectinolytic enzymes. These bacteria cause disease symptoms of blackleg on potato plants and soft rot on potato tubers and other vegetables, e.g., tomatoes, peppers, chicory, and ornamental plants [ 3 , 4 , 5 ]. The virulence of these pathogens results from the production of large quantities of plant-cell-wall-degrading enzymes (PCWDEs), i.e., pectinases, cellulases, and proteases that are secreted outside bacterial cells and allow for efficient maceration of plant tissue [ 6 ].…”

“…Our research group has been monitoring the occurrence of pectinolytic bacteria on seed potato plantations in Poland since 1996 [ 5 ]. The members of Pectobacteriaceae were also detected in some of the tested waterways in our country [ 36 ].…”