An S receptor kinase gene in self-compatible Brassica napus has a 1-bp deletion.
S locus glycoprotein (SLG) and S locus receptor kinase (SRK) cDNAs were isolated from an S allele present in a number of self-compatible Brassica napus lines. This A10 allele did not segregate with self-incompatibility in crosses involving other self-incompatible B. napus lines. The SLG-A10 cDNA was found to contain an intact open reading frame and was predicted to encode an SLG protein with sequence similarities to those previously associated with phenotypically strong self-incompatibility reactions. SLG-A10 transcripts were detected in the developing stigma at steady state levels even higher than those detected for SLG alleles linked with self-incompatibility. Analysis of the corresponding SRK-A10 cDNA showed that it was very similar to other S locus receptor kinase genes and was expressed predominantly in the stigma. However, a 1-bp deletion was detected in the SRK gene toward the 3' end of the SLG homology domain. This deletion would lead to premature termination of translation and the production of a truncated SRK protein. The A10 allele was determined to represent a B. oleracea S allele based on its segregation pattern with the B. oleracea S24 allele when both these alleles were present in the same B. napus background. These results suggest that a functional SRK gene is required for Brassica self-incompatibility.
Department of Molecular Biology and Genetics, University of Guelph, Ontario, Canada.
D R
DR
Goring
T L
TL
Glavin
U
U
Schafer
S J
SJ
Rothstein
D000595:Amino Acid Sequence; D001483:Base Sequence; D001937:Brassica / Q000235:genetics*; D004247:DNA; D005298:Fertility / Q000235:genetics; D015870:Gene Expression; D006023:Glycoproteins / Q000235:genetics; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000235:genetics; D011494:Protein Kinases / Q000235:genetics*; D016415:Sequence Alignment; D017421:Sequence Analysis; D017384:Sequence Deletion
D006023:Glycoproteins; D010940:Plant Proteins; C064156:self-incompatibility locus specific glycoprotein, Brassica; D004247:DNA; D011494:Protein Kinases; C079832:S-receptor kinase