【摘要】 利用RACE技术,获得了不结球白菜防卫素基因全长序列,命名为BcDF1.2(DDBJ登录号AB302891).序列分析发现,BcDF1.2全长532bp包含1个长度为96bp的内含子区域,该基因编码79个氨基酸残基组成的蛋白质,与其他植物的防卫素基因和抗真菌蛋白基因有较高的同源性.系统进化树分析表明,该基因在不同植物间具有高度保守性.基因组DNA杂交表明BcDF1.2属于较小的多基因家族.水杨酸和霜霉病原菌诱导后,该mRNA不仅在诱导的叶片中转录表达增加,而且在未诱导的系统叶片中表达增加.BcDF1.2在不结球白菜叶片中的转录表达特点表明可能参与对霜霉病的抗性反应.更多还原

【Abstract】 Using RACE technology,a plant denfensin gene was cloned from Brassica campestris ssp.chinensis genomic DNA.The plant denfensin gene,designated BcDF1.2,contains 532 bp nucleotides with a 96 bp intron sequence (DDBJ accession No.AB302891).BcDF1.2 encodes a polypeptide of 79 amino acids,and showed high degree of homology to other plant defensin genes and antifungal proteins.Phylogenetic analysis revealed the evolutionary conservation of this protein among different plants.Genomic DNA gel blot showed that BcDF1.2 belongs to a small multigene family.Upon inoculated with salicylic acid (SA) and P.parasitica,BcDF1.2 mRNA transcript was increased not only in infected leaves but also in uninfected systemic leaves.Expression characterization of BcDF1.2 in Brassica campestris ssp.chinensis leaves showed it might be involved in host resistance against downy mildew (DM).更多还原