Genetic and molecular characterization of the maize rp3 rust resistance locus.
In maize, the Rp3 gene confers resistance to common rust caused by Puccinia sorghi. Flanking marker analysis of rust-susceptible rp3 variants suggested that most of them arose via unequal crossing over, indicating that rp3 is a complex locus like rp1. The PIC13 probe identifies a nucleotide binding site-leucine-rich repeat (NBS-LRR) gene family that maps to the complex. Rp3 variants show losses of PIC13 family members relative to the resistant parents when probed with PIC13, indicating that the Rp3 gene is a member of this family. Gel blots and sequence analysis suggest that at least 9 family members are at the locus in most Rp3-carrying lines and that at least 5 of these are transcribed in the Rp3-A haplotype. The coding regions of 14 family members, isolated from three different Rp3-carrying haplotypes, had DNA sequence identities from 93 to 99%. Partial sequencing of clones of a BAC contig spanning the rp3 locus in the maize inbred line B73 identified five different PIC13 paralogues in a region of approximately 140 kb.
Webb
Craig A
CA
Department of Plant Pathology, Kansas State University, Manhattan, Kansas 66506-5502, USA.
Richter
Todd E
TE
Collins
Nicholas C
NC
Nicolas
Marie
M
Trick
Harold N
HN
Pryor
Tony
T
Hulbert
Scot H
SH
D000595:Amino Acid Sequence; D001483:Base Sequence; D001487:Basidiomycota / Q000472:pathogenicity*; D017931:DNA Primers; D017343:Genes, Plant; D006239:Haplotypes; D008540:Meiosis / Q000235:genetics; D008969:Molecular Sequence Data; D010641:Phenotype; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics*; D011995:Recombination, Genetic; D017386:Sequence Homology, Amino Acid; D003313:Zea mays / Q000235:genetics* / Q000382:microbiology
D017931:DNA Primers; D010940:Plant Proteins