The S receptor kinase gene determines dominance relationships in stigma expression of self-incompatibility in Brassica
Article first published online: 23 DEC 2001
The Plant Journal
Volume 26, Issue 1, pages 69–76, April 2001
How to Cite
Hatakeyama, K., Takasaki, T., Suzuki, G., Nishio, T., Watanabe, M., Isogai, A. and Hinata, K. (2001), The S receptor kinase gene determines dominance relationships in stigma expression of self-incompatibility in Brassica. The Plant Journal, 26: 69–76. doi: 10.1046/j.1365-313x.2001.01009.x
- Issue published online: 23 DEC 2001
- Article first published online: 23 DEC 2001
- Received 14 November 2000; revised 25 January 2001; accepted 30 January 2001.
- dominance relationships;
- S receptor kinase;
Self-incompatibility (SI) in Brassica is sporophytically controlled by the multi-allelic S locus. SI phenotypes of the stigma and pollen in an S heterozygote are determined by the two S haplotypes it carries; the two haplotypes may be co-dominant or exhibit a dominant/recessive relationship. Because the S receptor kinase (SRK) gene of the S locus was recently shown to determine the S haplotype specificity of the stigma, we wished to investigate whether SRK also plays a role in the dominance relationships between S haplotypes. We crossed plants carrying an SRK28 transgene with plants homozygous for one of five S haplotypes that are either co-dominant with, or recessive to, S28 haplotype in the stigma, and analyzed the SI phenotypes of the progeny. In all cases, the SI phenotype of the stigma of plants carrying the SRK28 transgene could be predicted by the known dominance relationships between the S haplotype(s) and the S28 haplotype. Moreover, in the S43 homozygote carrying the SRK28 transgene where the S43 phenotype in the stigma was masked by the presence of the SRK28, the transcript level of SRK28 was found to be much lower than that of SRK43. All these results suggest that the dominance relationships between S haplotypes in the stigma are determined by SRK, but not by virtue of its relative expression level.