Fine mapping of the Pc locus of Sorghum bicolor, a gene controlling the reaction to a fungal pathogen and its host-selective toxin.
Milo disease in sorghum is caused by isolates of the soil-borne fungus Periconia circinata that produce PC-toxin. Susceptibility to milo disease is conditioned by a single, semi-dominant gene, termed Pc. The susceptible allele (Pc) converts to a resistant form (pc) spontaneously at a gametic frequency of 10(-3) to 10(-4). A high-density genetic map was constructed around the Pc locus using DNA markers, allowing the Pc gene to be delimited to a 0.9 cM region on the short arm of sorghum chromosome 9. Physically, the Pc-region was covered by a single BAC clone. Sequence analysis of this BAC revealed twelve gene candidates. Several of the predicted genes in the region are homologous to disease resistance loci, including one NBS-LRR resistance gene analogue that is present in multiple tandem copies. Analysis of pc isolines derived from Pc/Pc sorghum suggests that one or more members of this NBS-LRR gene family are the Pc genes that condition susceptibility.
Nagy
Ervin D
ED
Department of Genetics, University of Georgia, Athens, GA, 30602, USA.
Lee
Tso-Ching
TC
Ramakrishna
Wusirika
W
Xu
Zijun
Z
Klein
Patricia E
PE
SanMiguel
Phillip
P
Cheng
Chiu-Ping
CP
Li
Jingling
J
Devos
Katrien M
KM
Schertz
Keith
K
Dunkle
Larry
L
Bennetzen
Jeffrey L
JL
D000483:Alleles; D000595:Amino Acid Sequence; D001203:Ascomycota / Q000472:pathogenicity*; D022202:Chromosomes, Artificial, Bacterial; D032461:Chromosomes, Plant; D003001:Cloning, Molecular; D003433:Crosses, Genetic; D018744:DNA, Plant; D018628:Gene Dosage; D020440:Gene Duplication; D005799:Genes, Dominant; D017343:Genes, Plant; D005819:Genetic Markers; D005838:Genotype; D008969:Molecular Sequence Data; D020161:Physical Chromosome Mapping; D018807:Polymorphism, Single-Stranded Conformational; D011995:Recombination, Genetic; D017386:Sequence Homology, Amino Acid; D045868:Sorghum / Q000235:genetics*; D014118:Toxins, Biological / Q000235:genetics*
D018744:DNA, Plant; D005819:Genetic Markers; D014118:Toxins, Biological