【摘要】 磷酸烯醇式丙酮酸羧化酶(phosphoenolpyruvate carboxylase,PEPCase,EC4.1.1.31)在植物代谢过程中发挥重要作用。本研究从蓝莓果实中克隆到磷酸烯醇式丙酮酸羧化酶编码基因VcPEPC。该基因开放阅读框全长为2 907 bp,可编码968个氨基酸,分子量为110.59 kD。由于该蛋白具有磷酸烯醇式丙酮酸羧化酶结构特征,认为VcPEPC属于PEPcase家族(pfam00311)。二级结构预测表明,VcPEPC蛋白序列含有双螺旋(54.44%)、扩展链(11.67%)、β转角(6.71%)以及无规则卷曲(27.17%)。进化树分析发现VcPEPC与瓜、蓖麻和葡萄遗传距离较近。反转录PCR分析表明,VcPEPC基因在蓝莓根、茎、叶、花、果实中均有表达。在奥尼尔叶片中的表达量高于蓝丰、布里吉塔和夏普兰,在夏普兰绿色大果中表达量较高,成熟后基因表达下调。更多还原

【Abstract】 Phosphoenolpyruvate carboxylase(PEPCase, EC4.1.1.31) plays an important role in plant metabolism.We cloned a Vc PEPC gene encoding PEPCase from fruit of blueberry. The open read frame of Vc PEPC gene was2 907 bp, encoding protein of 968 amino acids(aa) with 110.59 k D molecular weight. Because Vc PEPC protein owned a characteristics of phosphoenolpyruvate carboxylase, the gene should belong to PEPcase family(pfam00311). On the basis of secondary structure prediction, Vc PEPC protein included alpha helix(54.44%), extended strand(11.67%), beta turn(6.71%), and random coil(27.17%). The result of phylogenetic analysis revealed that the Vc PEPC had a close genetic distance with Cucumis sativus, Ricinus communis and Vitis vinifera. Reverse transcription PCR analysis showed that the Vc PEPC expressed in root, stem, leaf, flower and fruit of blueberry.The Vc PEPC expression level was higher in the leaf of O’Neal than that of Bluecrop, Briggitta and Sharpblue,however, it expressed highly in large green fruit, and then gradually down-regulated in ripe fruit of Sharpblue.更多还原