中国杏自交不亲和花粉特异SFB基因的鉴定与序列分析

Identification and Sequence Analysis of Pollen-sepecific SFB Genes in Self-incompatible Chinese Apricot (Prunus armeniaca)

利用花粉SFB基因的同源扩增结合内切酶酶切的方法,在9个中国杏品种中首次克隆了6个花粉SFB基因,对应花柱S-RNase基因序号将其分别命名为Par-SFB8、Par-SFB9、Par-SFB11、Par-SFB17、Par-SFB23和Par-SFB26,在GenBank上的登录号分别为EU652883、EU935588、EU652884、EU652885、EU652886和EU652887。序列分析表明杏的花粉SFB基因具有蔷薇科李属植物SFB基因的典型结构特征;其内含子位于5′端非翻译区,长度90～108bp,核苷酸序列的同源性为63.9%～93.3%。氨基酸序列的同源性比较表明,杏花粉SFB基因的种内同源性为73.7%～85.3%;与李属其他植物花粉SFB基因的种间同源性为75.2%～97.7%。利用特异PCR扩增进一步确定了杏的S9、S11、S17和S26单元型花柱S-RNase与花粉SFB基因间距离,表明花柱S-RNase与花粉SFB基因紧密连锁;同时组织特异性表达分析确定SFB基因在花粉组织中特异表达。以上结果说明获得的SFB基因为杏的花粉候选S基因。

Six pollen-specific SFB genes were cloned by PCR amplification from nine cultivars of apricot （Prunus armeniaca）native to China, these novel SFB genes were denoted as Par-SFBs, Par-SFB9, Par-SFBH, Par-SFB17, Par-SFB23 and Par-SFB26 in corresponding to style-specific S-RNases, respec- tively. The gene sequences were submitted to the GenBank and their accession number are EU652883, EU935588, EU652884, EU652885, EU652886 and EU652887, respectively. The apricot SFB genes showed similar structural characteristics to SFB genes of other Prunus species. Introns of SFBs were located at 5＇ terminal upstream of the initial codon, with intron lengths of 90 - 108 bp, and nucleotide sequence homologies of 63.9% - 93.3%. Based on amino acid sequence alignment, the similarity of SFB alleles ranged from 73.7% to 85.3% in P. armeniaca, and from 75.2% to 97.7% comparing with other Prunus species. The intergenic distances for the $9, Sn, Slz and 826 haplotypes were determined directly by specific PCR amplification, implying that the two genes are physically linked in apricot. The SFB genes are specifically expressed in pollen. All these evidence indicated that the SFB genes were good candidates for pollen S-determinants in apricot.