Commonality of self-recognition specificity of S haplotypes between Brassica oleracea and Brassica rapa.
We have identified several interspecific pairs of S haplotypes having highly similar SRK and SP11/SCR sequences between Brassica oleracea and Brassica rapa. The recognition specificities of S haplotypes in these pairs were examined with three different methods. Stigmas of interspecific hybrids between an S-32 homozygote in B. oleracea and an S-60 homozygote in B. rapa, which were produced to avoid the interspecific incompatibility between the two species, showed incompatibility to the pollen of an S-8 homozygote in B. rapa and to the pollen of an S-15 homozygote in B. oleracea, while it showed compatibility to the pollen of other S haplotypes, suggesting B. oleracea S-32 and B. rapa S-60 have the same recognition specificity as B. rapa S-8 and B. oleracea S-15. Pollen grains of transgenic S-60 homozygous plants in B. rapa carrying a transgene of SP11-24 from B. oleracea were incompatible to B. rapa S-36 stigma, indicating that B. oleracea S-24 and B. rapa S-36 have the same recognition specificity. Application of the SP11 protein of B. rapa S-41 and S-47 onto the surface of B. oleracea S-64 stigmas and S-12 stigmas, respectively, resulted in the incompatibility reaction to pollen grains of another S haplotype, but application onto the stigmas of other S haplotypes did not, suggesting that B. oleracea S-64 stigmas and S-12 stigmas recognized the B. rapa SP11-41 and SP11-47 proteins as self SP11 proteins, respectively. Besides having evolutionary implications, finding of many interspecific pairs of S haplotypes can provide insight into the molecular mechanism of self-recognition. Comparing deduced amino-acid sequences of SP11 proteins and SRK proteins in the pairs, regions of SP11 and SRK important for self-recognition are discussed.
Sato
Yutaka
Y
Graduate School of Agricultural Science, Tohoku University, Sendai 981-8555, Japan.
Fujimoto
Ryo
R
Toriyama
Kinya
K
Nishio
Takeshi
T
D001937:Brassica / Q000235:genetics*; D029741:Brassica rapa / Q000235:genetics*; D005298:Fertility / Q000235:genetics; D035264:Flowers / Q000187:drug effects / Q000235:genetics / Q000254:growth & development; D006023:Glycoproteins / Q000235:genetics; D006239:Haplotypes / Q000235:genetics*; D006824:Hybridization, Genetic; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000235:genetics / Q000494:pharmacology; D030821:Plants, Genetically Modified; D011058:Pollen / Q000187:drug effects / Q000235:genetics / Q000254:growth & development; D011494:Protein Kinases / Q000235:genetics; D011994:Recombinant Proteins / Q000494:pharmacology; D013045:Species Specificity
D006023:Glycoproteins; D010940:Plant Proteins; D011994:Recombinant Proteins; C431526:SP11 protein, Brassica; C064156:self-incompatibility locus specific glycoprotein, Brassica; D011494:Protein Kinases; C079832:S-receptor kinase