百合VAL2基因的克隆与表达分析

Cloning and Expression Analysis of VAL2 in Lilium Oriental Hybrid ‘Sorbonne’

以东方百合‘索邦’为材料,克隆获得VAL2基因(以下称LoVAL2)。序列分析显示,LoVAL2编码序列长度为2 793 bp,共编码930个氨基酸;预测LoVAL2蛋白具有5个结构域:PHD-L、B3、CW、ZnF-like和EAR结构域。系统进化分析显示,LoVAL2与天门冬亲缘关系较近,与玉米、铁皮石斛等亲缘关系次之,与拟南芥亲缘关系较远。荧光定量表达分析显示,LoVAL2在茎生根、嫩茎、成熟叶、嫩叶及花部组织中均有表达;LoVAL2在雌蕊和雄蕊中的表达于5 mm花蕾中呈现较高水平,随着花蕾发育表达水平下调,之后在雌、雄蕊中的表达水平又分别于20 mm、25 mm花蕾中显著上调,表明LoVAL2基因可能参与雌、雄蕊的早期以及后续发育;亚细胞定位发现LoVAL2在烟草表皮细胞中定位于细胞核,符合转录因子的核定位特征。

The VAL2 gene was cloned by using Lilium oriental hybrid ‘Sorbonne’as a material(hereinafter referred to as LoVAL2). Sequence analysis showed that the coding sequence of LoVAL2 was 2 793 bp long and LoVAL2 encoded 930 amino acids containing five domains: PHD-L, B3, CW, ZnF-like and EAR motif. Phylogenetic analysis showed that LoVAL2 was closely related to Asparagus officinalis, the following were Zea mays and Dendrobium catenatum, Arabidopsis thaliana and other plants were far away. Real-time RT-PCR expression analysis showed that LoVAL2 expressed in stem root, tender stem, upper leaf, lower leaf and floral organ;LoVAL2 expressed in four kinds of floral organs. The relatively high expression levels in the pistils and stamens occurred in 5 mm buds;afterwards, the expression levels were down-regulated with the development of flower buds;then, the expression levels were significantly up-regulated in the pistil of 20 mm buds and the stamen of the 25 mm buds, indicating that LoVAL2 may play an important role in the early and the subsequent development of the pistil and stamen. LoVAL2 was localized in the nucleus of tobacco epidermal cells, which was consistent with the nuclear localization characteristic of transcription factors.