Dickeya fangzhongdai sp. nov., a plant-pathogenic bacterium isolated from pear trees (Pyrus pyrifolia)

Abstract

Gram-stain-negative, pectinolytic bacteria were repeatedly isolated from pear trees displaying symptoms of bleeding canker in China. Three strains, JS5 T , LN1 and QZH3, had identical 16S rRNA gene sequences that shared 99 % similarity to the type strain of Dickeya dadantii. Phylogenetic analysis of strains JS5 T , LN1 and QZH3 with isolates representing all species of the genus Dickeya and related Pectobacterium species supported their affiliation to Dickeya. Multi-locus sequence typing employing concatenated sequences encoding recA, fusA, gapA, purA, rplB, dnaX and the intergenic spacer illustrated a phylogeny which placed strains JS5 T , LN1 and QZH3 as a distinct clade, separate from all other species of the genus Dickeya. Average nucleotide identity values obtained in comparison with all species of the genus Dickeya supported the distinctiveness of strain JS5 T within the genus Dickeya. Additionally, all three strains were phenotypically distinguished from other species of the genus Dickeya by failing to hydrolyse casein, and by producing acids from (À)-D-arabinose, (+)melibiose, (+)raffinose, mannitol and myo-inositol, but not from 5-keto-D-gluconate or b-gentiobiose. The name Dickeya fangzhongdai sp. nov. is proposed to accommodate these strains; the type strain is JS5 T

The phytopathogenic nature of Dickeya aquatica 174/2 and the dynamic early evolution of Dickeya pathogenicity

“…For each tree, the name and the annotation of the seed is provided in red. Tian et al (2016). Table S2 Genomic features of the Dickeya strains with completely sequenced genomes.…”

“…dieffenbachiae (Brady et al, 2012). More recently, three additional Dickeya species have been described: D. solani, isolated from potatoes and hyacinth (Van der Wolf et al, 2014;Slawiak et al, 2009), Dickeya aquatica from freshwater rivers , and Dickeya fangzhongdai from pear trees displaying symptoms of bleeding canker in China (Tian et al, 2016). Thus, the Dickeya genus now comprises eight species with distinctive phenotypic features (Supporting Information Table S1).…”

“…It is noteworthy, that in this study, strains M074 and M005, annotated as D. chrysanthemi and D. solani, respectively, branch inbetween D. dianthicola and the D. solani / D. dadantii group within Cluster II, thus far away from the type strains of their species . Dickeya fangzhongdai branched at the base of the Cluster II in a tree based on seven housekeeping genes (Tian et al, 2016). Finally, according to a tree based on six housekeeping genes, D. aquatica emerge just after the divergence of D. paradisiaca but before the divergence of Cluster I and Cluster II .…”

Plant–phytopathogen interactions: bacterial responses to environmental and plant stimuli

“…The enterobacterial plant pathogens of the genus Dickeya are responsible for soft rot disease in a wide range of angiosperm plant species in geographically diverse regions (Ma et al, 2007). This genus comprises eight species (D. chrysanthemi, D. dadantii, D. dianthicola, D. zeae, D. paradisiaca, D. solani, D. fangzhongdai and D. aquatica) (Parkinson et al, 2014;Tian et al, 2016;Zhang et al, 2016). Most of the results presented below are from studies of D. dadantii strain 3937 isolated from African violet (Saintpaulia ionantha), Molecular dialog between phytopathogens and plants 1703 the species chosen as a model by the Dickeya international community .…”

The effect of temperature on the phenotypic features and the maceration ability of Dickeya solani strains isolated in Finland, Israel and Poland

“…dianthicola, D. fangzhongdai D. paradisiaca, D. solani and D. zeae (Samson et al 2005;Brady et al 2012;van der Wolf et al 2014;Parkinson et al 2014;Tian et al 2016). Bacteria from this genus were known to cause disease symptoms, especially in tropical and subtropical climates, on a large number of host plant species, including many economically important crops like potato, maize and banana (Ma et al 2007).…”