炭疽菌诱导的枇杷病程相关基因EjPR1的克隆及其表达分析

Cloning and Expression of a Pathogenesis Related Protein Gene EjPR1 from Loquat Induced by Colletotrichum gloeosporioides

以炭疽病病原菌(Colletotrichum gloeosporioides)处理的枇杷高抗品种‘Peluches’的叶片为材料,利用RT-PCR和RACE克隆技术,获得枇杷病程相关蛋白1基因的cDNA全长序列,命名为EjPR1。该基因全长为731 bp(GenBank登录号为MN92775),5′端非编码区79 bp,3′端非编码区91 bp。其中ORF阅读框为561 bp,编码186个氨基酸,蛋白质等电点为5.63,分子量为21485.34,其预测结果的理论值与原核表达结果一致。序列分析结果表明,该基因编码的氨基酸序列与其他6种蔷薇科植物PR1蛋白的氨基酸序列相似性在76.41%~94.36%之间。接种炭疽菌后时序表达分析结果表明,该基因在高抗品种‘Peluches’中受病原菌诱导后明显上调表达,在接种后96 h最高,但在高感品种‘森尾早生’中无明显变化,说明EjPR1可能参与了枇杷的抗病防御过程。

A full length cDNA of pathogenesis-related protein 1 gene named EjPR1 was obtained from the leaves of‘Peluches’which was a loquat cultivar with high resistance to anthracnose treated by Colletotrichum gloeosporioides using RT-PCR and RACE technology.Bioinformatics analysis indicated that the full length of EjPR1 was 731 bp(GenBank number:MN92775),the length of 5′UTR and 3′UTR were 79 bp and 91 bp,respectively.The length of open reading frame(ORF)was 561 bp encoding 186 amino acids with isoelectric point 5.63 and molecular weight 21485.34 D which was consistent with the results of prokaryotic expression.Multiple alignment analysis based on the amino acids encoded by different PR1 genes from six other species of Rosaceae showed that EjPR1 was conserved among them with the similarity of 76.41%-94.36%.The results of time series expression analysis after inoculation with anthrax indicated that EjPR1 expression was up-regulated by infection and the highest expression was observed 96 h after inoculation in highly resistant cultivar while there was no significant difference in highly susceptible cultivar.It was speculated that EjPR1 might be involved in disease defense of loquat.