InterPro domain: IPR035446

In Brassica species, S locus glycoproteins (SLGs) are involved in self-incompatibility, a mechanism that regulates the acceptance or rejection of pollen to prevent self-fertilization [ 1 , 2 ]. SLGs accumulate in papillar cells of the stigma, at the site where inhibition of self-pollen tube development has been shown to occur [ 3 ].

This family also includes related proteins from Arabidopsis and epidermis-specific secreted glycoprotein EP1 from carrot, which has sequence homology to Brassica SLGs. EP1 is not involved in self-incompatibility, and its expression in seedlings rules out an specific role in pollination. Its role is not clear [ 4 ].

1. Molecular characterization of the S locus in two self-incompatible Brassica napus lines. Plant Cell 8, 2369-80
2. The S locus of flowering plants: when self-rejection is self-interest. Trends Genet. 8, 381-7
3. The S-locus specific glycoproteins of Brassica accumulate in the cell wall of developing stigma papillae. Dev. Biol. 134, 462-72
4. The carrot secreted glycoprotein gene EP1 is expressed in the epidermis and has sequence homology to Brassica S-locus glycoproteins. Plant J. 4, 855-62