Host Specificity and Differential Pathogenicity of Pectobacterium Strains from Dicot and Monocot Hosts

Abstract

Recent phylogenetic studies have transferred certain isolates from monocot plants previously included in the heterogeneous group of Pectobacteriumcarotovorum (Pc) to a species level termed Pectobacterium aroidearum. The specificity of Pectobacterium associated infections had received less attention, and may be of high scientific and economic importance. Here, we have characterized differential responses of Pectobacterium isolates from potato (WPP14) and calla lily (PC16) on two typical hosts: Brassica oleracea var. capitata (cabbage) a dicot host; and Zantedeschia aethiopica (calla lily) a monocot host. The results revealed clear host specific responses following infection with the two bacterial strains. This was demonstrated by differential production of volatile organic compounds (VOCs) and the expression of plant defense-related genes (pal, PR-1, lox2, ast). A related pattern was observed in bacterial responses to each of the host’s extract, with differential expression of virulence-related determinants and genes associated with quorum-sensing and plant cell wall-degrading enzymes. The differences were associated with each strain’s competence on its respective host.

Isolation and Genome Analysis of Pectobacterium colocasium sp. nov. and Pectobacterium aroidearum, Two New Pathogens of Taro

“…Some SRP pathogens may exhibit broad host ranges in laboratory studies, but have only been isolated from limited hosts in nature ( Hu et al, 2018 ). Recent studies have started to examine the host range and host specialization of Pectobacterium pathogens ( Khadka et al, 2020 ), but more efforts are needed to systematically investigate this issue.…”

Analysis of the Taxonomy, Synteny, and Virulence Factors for Soft Rot Pathogen Pectobacterium aroidearum in Amorphophallus konjac Using Comparative Genomics

“…aroidearum , although it remains possible that konjac soft rot is caused by more than one bacterial pathogen. In addition, considerable variation exists in regard to host specificity for Soft Rot Pectobacteriaceae (SRP; Khadka et al, 2020 ). Some SRP have wide host ranges, while others have only one or a few plant species ( Toth et al, 2021a ).…”

Phylogenetic and phenotypic analyses on Dickeya spp. isolated from different host plants in Taiwan

“…A study on distinct Pectobacterium strains showed that different host–pathogen combinations result in different disease severity. These differences were accompanied by differential expression of defence‐related genes and virulence‐associated genes in the plants and the pathogens, respectively (Khadka et al., 2020). In addition, different Pectobacterium strains could also induce distinct arrays of volatile organic compounds (VOCs) in the same host (Khadka et al., 2020), and some VOCs may enable neighbouring plants/organs to elicit defence responses (Ponzio et al., 2013).…”

“…in Oncidium orchids because the latter triggers a strong immune response in the host plant (Lin et al., 2015). Another study also showed that the expression of Pectobacterium virulence‐associated genes is differentially regulated between strains and that the expression patterns vary depending on the treatment of different plant extracts (Khadka et al., 2020). These findings suggest that genetic and phenotypic variations among soft rot bacteria could lead to different plant–pathogen interactions, which may in turn result in different symptom severities.…”