The broad-spectrum potato cyst nematode resistance gene (Hero) from tomato is the only member of a large gene family of NBS-LRR genes with an unusual amino acid repeat in the LRR region.
The Hero gene of tomato is a broad spectrum resistance gene that confers a high level of resistance to all pathotypes of the potato cyst nematodes Globodera rostochiensis and partial resistance to G. pallida. The gene was identified by map-based cloning, sequencing and complementation analysis of two susceptible tomato lines with an array of 13 overlapping cosmids spanning a total distance of 135 kb. Hero encodes a protein with a nucleotide-binding site (NBS) and a leucine-rich-repeat (LRR) domain and is a member of a gene family of 14 highly homologous genes, which are clustered within a continuous 118-kb region. The isolated Hero gene displayed resistance to various G. rostochiensis pathotypes and partial resistance to G. pallida pathotype Pa2/3 in transgenic tomato lines. None of the Hero homologues conferred resistance to G. rostochiensis pathotypes. Hero can be distinguished from its homologues by the length of a compound hexanucleotide microsatellite, which codes for a charged and repetitive amino acid domain within the LRR. We propose that the expansion of this microsatellite may be involved in the evolution of the Hero resistance gene.
Ernst
Karin
K
Institut für Pflanzengenetik und Kulturpflanzenforschung, Corrensstrasse 3, D-06466 Gatersleben, Germany. karin.ernst@rz.uni-duesseldorf.de
Kumar
Amar
A
Kriseleit
Doris
D
Kloos
Dorothee-U
DU
Phillips
Mark S
MS
Ganal
Martin W
MW
D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D017343:Genes, Plant / Q000235:genetics*; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D018551:Solanum lycopersicum / Q000235:genetics* / Q000469:parasitology*; D018895:Microsatellite Repeats / Q000235:genetics; D005810:Multigene Family / Q000235:genetics; D009348:Nematoda / Q000502:physiology*; D010935:Plant Diseases / Q000235:genetics; D010940:Plant Proteins / Q000737:chemistry* / Q000235:genetics; D030821:Plants, Genetically Modified; D020449:Repetitive Sequences, Amino Acid; D016415:Sequence Alignment
D010940:Plant Proteins