中文摘要：

根据白菜花粉特异的多聚半乳糖醛酸酶（PG）基因BcMF6的全长序列设计引物，通过PCR直接扩增的方法从茎瘤芥（Brassica funcea Czem．et Coss vat．tumida Tsen et Lee）‘浙桐1号’和分蘖芥（Brassica juncea var．multiceps Tsen et Lee）‘雪里蕻’中克隆到了BcMF6的同源基因BjMF6t和BjMF6m。BjMF6t和BjMF6m的序列完全相同，故合称BjMF6。该基因与BcMF6在DNA水平的相似性高达99．6％。Blast分析发现它与拟南芥外切PG基因在氨基酸水平上有很高的相似性，并且具有所有PG基因特有的功能结构域和活性位点，推测BjMF6属于PG基因。通过序列分析和系统树构建进一步证明了该基因可能是与花粉发育相关的PG基因。

英文摘要：

In the paper, BjMF6t and BjMF6m gene, homologous with the BcMF6 gene encoding pollenspecific polygalacturonase （PG） of Chinese cabbage, was cloned from Brassica juncea Czern. et Coss var. tumida Tsen et Lee and Brassica juncea var. multiceps Tsen et Lee. The two genes were found to have an identical DNA sequence, so, they were given the same name BjMF6. The BjMF6 gene showed 99.6% overall DNA similarity with that of BcMF6. Blast result showed that it also shared high similarity to PG genes in Arabidopsis thaliana. Sequence analysis revealed that one potential PG active position and four highly conserved domains of the plant and fungal PGs were present in BjMF6 gene. Furthermore, phylogenetic analysis indicated that BjMF6 might fall into the category of clade-C, which is comprised entirely of genes expressed in pollen. All these results suggested that BjMF6 might encode a PG related to pollen development.