title: Horizontal gene and chromosome transfer in plant pathogenic fungi affecting host range.
abstract: Plant pathogenic fungi adapt quickly to changing environments including overcoming plant disease resistance genes. This is usually achieved by mutations in single effector genes of the pathogens, enabling them to avoid recognition by the host plant. In addition, horizontal gene transfer (HGT) and horizontal chromosome transfer (HCT) provide a means for pathogens to broaden their host range. Recently, several reports have appeared in the literature on HGT, HCT and hybridization between plant pathogenic fungi that affect their host range, including species of Stagonospora/Pyrenophora, Fusarium and Alternaria. Evidence is given that HGT of the ToxA gene from Stagonospora nodorum to Pyrenophora tritici-repentis enabled the latter fungus to cause a serious disease in wheat. A nonpathogenic Fusarium species can become pathogenic on tomato by HCT of a pathogenicity chromosome from Fusarium oxysporum f.sp lycopersici, a well-known pathogen of tomato. Similarly, Alternaria species can broaden their host range by HCT of a single chromosome carrying a cluster of genes encoding host-specific toxins that enabled them to become pathogenic on new hosts such as apple, Japanese pear, strawberry and tomato, respectively. The mechanisms HGT and HCT and their impact on potential emergence of fungal plant pathogens adapted to new host plants will be discussed.
authors.affiliation: Laboratory of Phytopathology, Wageningen University, Wageningen, The Netherlands.
authors.forename: Rahim
authors.initials: R
authors.lastname: Mehrabi
authors.forename: Ali H
authors.initials: AH
authors.lastname: Bahkali
authors.forename: Kamel A
authors.initials: KA
authors.lastname: Abd-Elsalam
authors.forename: Mohamed
authors.initials: M
authors.lastname: Moslem
authors.forename: Sarrah
authors.initials: S
authors.lastname: Ben M'barek
authors.forename: Amir Mirzadi
authors.initials: AM
authors.lastname: Gohari
authors.forename: Mansoor Karimi
authors.initials: MK
authors.lastname: Jashni
authors.forename: Ioannis
authors.initials: I
authors.lastname: Stergiopoulos
authors.forename: Gert H J
authors.initials: GH
authors.lastname: Kema
authors.forename: Pierre J G M
authors.initials: PJ
authors.lastname: de Wit
mesh_terms: D001203:Ascomycota / Q000235:genetics* / Q000472:pathogenicity / Q000502:physiology; D015825:Chromosomes, Fungal / Q000235:genetics*; D022761:Gene Transfer, Horizontal; D058507:Host Specificity; D010935:Plant Diseases / Q000382:microbiology*; D010944:Plants / Q000382:microbiology*