草莓PIF3基因的克隆及表达分析

Cloning and Expression Analysis of PIF3 Gene in Fragaria × ananassa

光敏色素互作因子(phytochrome-interacting factors, PIFs)是一类bHLH转录因子。为探究其基因功能,本研究根据预测的栽培草莓(Fragaria×ananassa) PIF3序列设计引物,从‘红颜’(cv.Benihoppe)草莓中克隆得到FaPIF3的编码区及启动子区序列,其开放阅读框(ORF)长度为2 121 bp,编码706个氨基酸残基。生物信息学预测表明,FaPIF3具有HLH家族保守结构域,而无跨膜结构域和信号肽;系统进化树显示,该蛋白与蔷薇科植物具有很近的亲缘关系。通过获得的2 652 bp的启动子区序列进行启动子元件预测,发现FaPIF3具有大量的光响应元件。半定量PCR显示,FaPIF3在草莓果实成熟期间表达量稳定,在花和嫩叶中表达量较高。亚细胞定位结果证实,Fa PIF3位于细胞核内。

Phytochrome-interacting factors （PIFs） is a basic helix-loop-helix （bHLH） transcription factor. For further study of its gene function, primers were designed according to predicted PIF3 sequence from cultivated strawberries （Fragaria×ananassa） and the FaPIF3 coding region and promoter region sequence were cloned from Benihoppe strawberry. FaPIF3 contained an opening reading frame of 2 121 bp, coding 706 amino acids residues. Bioinformatics prediction showed that it had an HLH family conserved domain and had no trans-membrane domain or signal peptide. Phylogenetic tree showed that FaPIF3 protein had a closer relationship with Rosaceae plants. Through the prediction of promoter elements from the obtained 2 652 bp promoter region sequence, FaPIF3 was found to contain a number of light responsive elements. Semi quantitative PCR analysis showed that the expression of FaPIF3 was stable during fruiting stage in strawberry, and the expression level was higher in flowers and young leaves. Subcellular localization analysis indicated that FaPIF3 was targeted to the nuclear.