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.
Institut für Pflanzengenetik und Kulturpflanzenforschung, Corrensstrasse 3, D-06466 Gatersleben, Germany. karin.ernst@rz.uni-duesseldorf.de
Karin
K
Ernst
Amar
A
Kumar
Doris
D
Kriseleit
Dorothee-U
DU
Kloos
Mark S
MS
Phillips
Martin W
MW
Ganal
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