Abstract: The stigmas were from collected self-pollination and cross-pollination of Brassica oleracea L. var. capitata L. and were used to analyze protein expression profiles. We obtained a protein that was down-regulation expression in self-pollination and up-regulation in cross-pollination treatments，which was named BoPLL. Moreover，transcriptomic analysis also showed BoPLL was up-regulated at 0–30 min and down-regulated at 30–60 min in self-pollination process，while it was up-regulated in cross-pollination process. The CDS of BoPLL was 1 212 bp in length，encoding 403 amino acids of BoPLL. Sequence analysis found BoPLL contained a high conserved PASTA domain and a CMM-10 domain，moderate conserved PbH1 domain，and a low conserved HYDRO domain，indicating it was a typical PLL protein. Chromosomal location displayed that BoPLL is not linked with S locus genes. Phylogenetic tree analysis showed that Brassica oleracea L. BoPLL was more close to Arabidopsis thaliana AtPLL rather than Medicago truncatula MtPLL. RT-PCR analysis found BoPLL was predominantly expressed in pollen and stigma，with lower expression level of BoPLL in pistil than pollen，and no expression in leaf，flower bud，sepal and petal. qRT-PCR analysis revealed that the mRNA in 15~60 min expression patterns of BoPLL was similar with the RNAseq analysis. Based on those results，we speculated that BoPLL was involved in SI response in B. oleracea.

Key words: Brassica oleracea, BoPLL, gene cloning, location, expression analysis