The nematode resistance gene Mi of tomato confers resistance against the potato aphid.
Resistance against the aphid Macrosiphum euphorbiae previously was observed in tomato and attributed to a novel gene, designated Meu-1, tightly linked to the nematode resistance gene, Mi. Recent cloning of Mi allowed us to determine whether Meu-1 and Mi are the same gene. We show that Mi is expressed in leaves, that aphid resistance is isolate-specific, and that susceptible tomato transformed with Mi is resistant to the same aphid isolates as the original resistant lines. We conclude that Mi and Meu-1 are the same gene and that Mi mediates resistance against both aphids and nematodes, organisms belonging to different phyla. Mi is the first example of a plant resistance gene active against two such distantly related organisms. Furthermore, it is the first isolate-specific insect resistance gene to be cloned and belongs to the nucleotide-binding, leucine-rich repeat family of resistance genes.
Department of Nematology, University of California, Davis, CA 95616, USA.
M
M
Rossi
F L
FL
Goggin
S B
SB
Milligan
I
I
Kaloshian
D E
DE
Ullman
V M
VM
Williamson
D000818:Animals; D001042:Aphids / Q000472:pathogenicity*; D001483:Base Sequence; D003001:Cloning, Molecular; D017931:DNA Primers / Q000235:genetics; D018744:DNA, Plant / Q000235:genetics; D015870:Gene Expression; D017343:Genes, Plant; D005816:Genetic Complementation Test; D018551:Solanum lycopersicum / Q000235:genetics* / Q000469:parasitology*; D008969:Molecular Sequence Data; D009348:Nematoda / Q000472:pathogenicity*; D018515:Plant Leaves / Q000235:genetics; D030821:Plants, Genetically Modified
D017931:DNA Primers; D018744:DNA, Plant