关键词: 芜菁, NAC转录因子, 基因分离, 半定量RT-PCR, 组织原位杂交

Abstract: BcNAC2，a NAC transcription factor gene，has been successfully isolated from turnip[Brassica campestris L. ssp. rapifera（Matzg）Sinsk，syn. B. rapa L.]using the primers designed from the sequence of the NAC2 gene in Arabidopsis thaliana. Sequence analysis results showed that the full length of genomic DNA contained six extrons and five introns，and the open reading frame（ORF）was 1 683 bp coding 560 amino acids. In addition，the sequence of BcNAC2 was much conserved comparing with those of other 30 NAC proteins，and it shared the highest homology with A. thaliana among them. In addition，there are significant difference for the motif numbers between the BcNAC2 and AtNAC2 functional domains. Moreover，RT-PCR results indicated that BcNAC2 gene presented the character of constitutive expression partially，and highest expression at 8 days after pollination. In situ hybridization result also proves that it is one of the high expression abundance genes during embryo sac development. Therefore，BcNAC2 probably involved in the development of seed or embryo in the turnip.

Key words: turnip, Brassica campestris L. ssp. rapifera（Matzg）Sinsk, syn. B. rapa L., NAC transcription factor, gene isolation, RT-PCR, in situ hybridization