中文摘要：

S-富含半胱氨酸蛋白（SCR）是自交不亲和雄性决定因子，为了比较甘蓝不同S单倍型SCR基因结构和蛋白分子特性，依据mRNA的ployA序列和SCR保守氨基酸序列设计引物，利用巢式PCR技术分别获得了6种甘蓝（Brassic0oleFaCe0L．）D3、E1、240、A1、N1和G1的SCR基因的部分eDNA序列，均包含YUTR。生物信息学分析表明，6条cDNA序列长度分别为319、311、290、288、385和377bp，分别编码1个58、58、58、58、58和55个氨基酸的SCR蛋白，其中D3的SCR与SCR3序列一致，甘蓝E1、240、A1和N1的SCR与Js勰7序列一致，而甘蓝G1的SCR为一个新的S单倍型基因。研究表明，不同S单倍型的SCR二级结构和三维结构都有差异，其与s-位点受体激酶（sRK）相互作用的氨基酸在SCR分子表面，富含碱性氨基酸，且SRK—SCR相互作用需要静电荷参与。同时研究还表明，甘蓝自交不亲和性强度多样性，除了SCR和SRK本身作用能力因素以外，还与SCR和SRK分子的数量有关，而SCR的数量是通过3＇UTR在mRNA水平调控的。分析表明，SCR的进化速度很快，并且3＇UTR的进化速度高于氨基酸编码区的进化速度。本研究为进一步探索和利用自交不亲和机制提供了理论基础。

英文摘要：

Many flowering plants possess a self-incompatibility system to prevent inbreeding. In Brassica oleracea, self-incompatibility is genetically controlled by S-locus cysteine rich protein （SCR） and S-locus receptor kinase （SRK）. The SCR is the determinant of pollen S-haplotype specificity. In order to compare the structure of the gene and molecular characterization of the protein among the allelic SCRs, the nested PCR primers were designed on the basis of the conserved amino acids in the signal peptide＇s cleavage site and the ploy A of mRNA. Here we cloned partial cDNA sequence of SCR from six Brassica oleracea L.. Sequence analysis showed that the cDNA sequence of SCR in D3, El, 240, A1, N1 and G1 were 319, 311,290, 288, 385 and 377 bp, respectively, which all encompassed 3＇UTR. Their coding regions predicted a protein of 58,58, 58, 58, 58 and 55 amino acids, respectively. The protein sequences were identical between SCR-D3 and SCR3. SCR-E1, SCR-240, SCR-A1 and SCR-E1 also had the same sequences, and they were all identical to the SCR7. The SCR of G1 was a new S haplotype gene. Although SCR-E1, SCR-240, SCR-A1 and SCR-E1 were the same S haplotype, their 3＇UTR were different. For example, the length, the polyadenylation signal and the adenine nucleotide＇s content were different among them. Sequencing and bioinformatic analysis indicated that there were some differences in the secondary structure and the 3-dimentional structure of the six SCRs, suggesting that the interactions of SCR with SRK required strict complementary space. All SCRs had potential phosphorylation sites, but no glycosylation sites. It showed that the phosphorylation of SCR might play roles in signal transduction of self-incompatibility. Furthermore, the amino acid residues interacting with SRK were situated on the surface of the SCR molecule, and most of these amino acid residues were basic amino acid. So, we suggested that the process of SCR interacting with SRK required the participation of the static charge. Hereby, we provided