This family consists of several Plant self-incompatibility response (SCRL) proteins. The male component of the self-incompatibility response in Brassica has been shown to be encoded by the S locus cysteine-rich gene (SCR). SCR is related, at the sequence level, to the pollen coat protein (PCP) gene family whose members encode small, cysteine-rich proteins located in the proteo-lipidic surface layer (tryphine) of Brassica pollen grains [1].

1: Two large Arabidopsis thaliana gene families are homologous to the Brassica gene superfamily that encodes pollen coat proteins and the male component of the self-incompatibility response. Vanoosthuyse V, Miege C, Dumas C, Cock JM; Plant Mol Biol 2001;46:17-34. PMID:11437247