Sequence and structural diversity of the S locus genes from different lines with the same self-recognition specificities in Brassica oleracea.
Self-incompatibility (SI) is a mechanism for preventing self-fertilization in flowering plants. In Brassica, it is controlled by a single multi-allelic locus, S, and it is believed that two highly polymorphic genes in the S locus, SLG and SRK, play central roles in self-recognition in stigmas. SRK is a putative receptor protein kinase, whose extracellular domain exhibits high similarity to SLG. We analyzed two pairs of lines showing cross-incompatibility (S(2) and S(2-b); S(13) and S(13-b)). In S(2) and S(2-b), SRKs were more highly conserved than SLGs. This was also the case with S(13) and S(13-b). This suggests that the SRKs of different lines must be conserved for the lines to have the same self-recognition specificity. In particular, SLG(2-b) showed only 88. 5% identity to SLG(2), which is comparable to that between the SLGs of different S haplotypes, while SRK(2-b) showed 97.3% identity to SRK(2) in the S domain. These findings suggest that the SLGs in these S haplotypes are not important for self-recognition in SI.
Kusaba
M
M
Institute of Radiation Breeding, National Institute of Agrobiological Resources, Ministry of Agriculture, Forestry and Fisheries, Ohmiya-machi, Naka-gun, Ibaraki, 319-2293, Japan. kusaba@irb.affrc.go.jp
Matsushita
M
M
Okazaki
K
K
Satta
Y
Y
Nishio
T
T
D000595:Amino Acid Sequence; D001483:Base Sequence; D001937:Brassica / Q000235:genetics*; D003001:Cloning, Molecular; D017931:DNA Primers; D018076:DNA, Complementary; D006023:Glycoproteins / Q000737:chemistry / Q000235:genetics*; D006239:Haplotypes; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics*; D017386:Sequence Homology, Amino Acid
D017931:DNA Primers; D018076:DNA, Complementary; D006023:Glycoproteins; D010940:Plant Proteins; C064156:self-incompatibility locus specific glycoprotein, Brassica