Open AccessComparative genomics of Spiraeoideae‐infecting Erwinia amylovora strains provides novel insight to genetic diversity and identifies the genetic basis of a low‐virulence strain
Author(s) -
Zeng Quan,
Cui Zhouqi,
Wang Jie,
Childs Kevin L.,
Sundin George W.,
Cooley Daniel R.,
Yang ChingHong,
Garofalo Elizabeth,
Eaton Alan,
Huntley Regan B.,
Yuan Xiaochen,
Schultes Neil P.
Publication year - 2018
Publication title -
molecular plant pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.945
H-Index - 103
eISSN - 1364-3703
pISSN - 1464-6722
DOI - 10.1111/mpp.12647
Subject(s) - biology , virulence , genetic diversity , genomics , genetics , strain (injury) , comparative genomics , erwinia , genome , microbiology and biotechnology , gene , population , demography , sociology , anatomy
Summary Erwinia amylovora is the causal agent of fire blight, one of the most devastating diseases of apple and pear. Erwinia amylovora is thought to have originated in North America and has now spread to at least 50 countries worldwide. An understanding of the diversity of the pathogen population and the transmission to different geographical regions is important for the future mitigation of this disease. In this research, we performed an expanded comparative genomic study of the Spiraeoideae‐infecting (SI) E. amylovora population in North America and Europe. We discovered that, although still highly homogeneous, the genetic diversity of 30 E. amylovora genomes examined was about 30 times higher than previously determined. These isolates belong to four distinct clades, three of which display geographical clustering and one of which contains strains from various geographical locations (‘Widely Prevalent’ clade). Furthermore, we revealed that strains from the Widely Prevalent clade displayed a higher level of recombination with strains from a clade strictly from the eastern USA, which suggests that the Widely Prevalent clade probably originated from the eastern USA before it spread to other locations. Finally, we detected variations in virulence in the SI E. amylovora strains on immature pear, and identified the genetic basis of one of the low‐virulence strains as being caused by a single nucleotide polymorphism in hfq , a gene encoding an important virulence regulator. Our results provide insights into the population structure, distribution and evolution of SI E. amylovora in North America and Europe.