基于越橘果实转录组测序WBC型转运蛋白基因发掘及表达分析

Gene discovery and expression analysis of WBC transporters based on blueberry fruit transcriptome analysis

为发掘越橘中WBC型(White brown complex)ABC转运蛋白(ATP-binding cassette transporters)基因,研究其与次生代谢物质(Secondary metabolite)运输关系,从越橘果实转录组测序文库中筛选出21个编码WBC型转运蛋白基因。其中10个基因上调表达,11个基因下调表达,10个上调表达基因中有7个基因显著上调表达。以越橘‘北陆’(Northland)根、茎、叶芽、叶、花芽、花、绿果、粉果、蓝果、蓝果种子、蓝果果皮和蓝果果肉为试验材料,对7个显著上调表达基因进行实时荧光定量PCR(Real-time fluorescence quantitative PCR,q RT-PCR)分析,研究在越橘各个器官和果实发育不同阶段中表达模式。结果表明,越橘中7个WBC转运蛋白基因中有5个基因在果皮和果肉中的表达情况与转录组分析结果一致。越橘所有组织器官中均能检测到WBC型转运蛋白表达,但表达量不同。Unigene5067_All和Unigene27766_All在根中表达量最高,Unigene14517_All、Unigene27928_All和Unigene29820_All分别在茎、花和蓝果中表达量最高,Unigene34381_All和Unigene34438_All表达量从绿果、粉果到蓝果呈递增表达模式,与越橘中花色素苷累积呈现一致性,推测这两个WBC转运蛋白基因可能参与越橘次生代谢物运输。有助于阐明越橘中WBC转运蛋白生理生化功能。

To explore the white brown complex （WBC） type gene of ATP-binding cassette （ABC） transporters in blueberry, and study its relationship with secondary metabolite transportation, 21 Unigenes encoding WBC transporter were screened out from blueberry fruit transcriptome. Total 10 Unigenes were up-regulated expression, of which seven Unigenes were significantly up-regulated, and 11 genes were down-regulated expression. Real-time fluorescence quantitative PCR （qRT-PCR） was performed on seven significantly up-regulated Unigenes to examine the expression pattern during blueberry development stage and several different organs, including roots, stems, leaf buds, leaves, blossoms, blossom buds, green fruits, pink fruits, blue fruits, seeds of blue fruit, peel of blue fruit and pulps of blue fruit as experimental materials. The qRT-PCR results showed that the expression pattern of five genes were consistent with the results of transcriptome analyses. WBC genes expressed in all tested tissues and organs of blueberry, but had different expression levels. Unigene5067_AII and Unigene27766_AII highly expressed in roots, Unigene 14517_AII, Unigene27928_AII and Unigene29820_AII highly expressed in stems, blossoms and blue-fruits, respectively. Furthermore, Unigene34381_AII and Unigene34438_AII showed an increasing expression pattern from green-fruits, pink-friuts to blue-fruits, this concurrence with the accumulation of anthocyanins in blueberry, the results indicated the two WBC transporter genes maybe participate in the secondary metabolite transportation of blueberry. This study could help elucidate the biological and physiological functions of WBC transporters in blueberry.