用PCR-差别筛选法分离和克隆水稻受稻瘟病菌诱导的cDNA片段

以水稻抗瘟性近等基因系H7R和H7S为材料，采用PCR-差别筛选（PCR-based differential screening）的方法分离和克隆水稻受稻瘟病菌诱导的抗性相关基因。第一轮筛选获得42个差异表达的cDNA克隆，经PCR扩增，转膜，反向Northern杂交后，得到12个阳性cDNA克隆。Northern证实其中一个克隆（暂命名为D2，约2.2kb）为受稻瘟病菌诱导的特异反应基因(片段)。

Isolation and Cloning of cDNAs Induced by Magnaporthe grisea From Rice Using a PCR-based Differential Screening Method

A PCRbased differential screening method was employed to isolate and clone blast resistancerelated genes induced by Magnaporthe grisea with a pair of rice near isogenic lines (NIL) H7R and H7S . From the primary differential screening step , a total of 42 impure pools of candidates were selected. Each pool of clones was amplified by PCR and then the PCR products were blotted onto filters. Twelve positive cDNA clones were obtained after reverseNorthern hybridization. The results by Northern analyses showed that one cDNA clone (named D2, 2.2kb in length) induced by M. grisea was expressed only during special stages of plantpathogen interaction. The advantages and disadvantages of PCRbased differential screening method and further characterization were also discussed.