玉米大斑病菌钙调磷酸酶A亚基的克隆与特征分析

根据已知病原真菌钙调磷酸酶A亚基(Calcineurin A, CNA)丝苏蛋白磷酸酶保守结构域设计引物, 从玉米大斑病菌cDNA中扩增出CNA基因片段。利用cDNA末端快速克隆(Rapid amplification of cDNA ends, RACE)手段获得该基因全长cDNA序列(GenBank登录号: EF 407562)。Southern杂交结果显示, 该基因在玉米大斑病菌基因组只有1个拷贝。CNA特异性抑制剂Cyclosporin A对玉米大斑病菌分生孢子和附着胞发育有抑制作用, 抑制作用与抑制剂浓度呈正相关, 相同浓度的抑制剂对附着胞形成的抑制作用大于对孢子萌发的抑制。经CsA(5µg/mL)处理后, 玉米大斑病菌分生孢子不能侵入玉米叶片, 初步表明CNA基因参与玉米大斑病菌的致病过程。

Molecular cloning and characterization of calcineurin A in Se-tosphaeria turcica

A Setosphaeria turcica gene encoding the catalytic subunit of calcineurin was cloned using degenerated primers corresponding to conserved domains of Ser/Thr protein phosphatases and its complete cDNA (GenBank accession No. EF 407562) was obtained with RACE method. It’s validated single copied model by southern hybridization. Furthermore, the CNA inhibitor Cyclosporin A (CsA) exhibited potent antifungal activity against conidial germination and appressorium formation of S. turcica. The inhibition ratio was positively correlated to CsA concentration. However, appressorium formation was more sensitive than conidium germination to the inhibitor at the same concentration. It was suggested that CNA might play an important role in the pathogenicity of S. turcica.