PWL基因家族在稻瘟病菌中的分布及变异初探

A primary study on distribution and variability of PWLgene family in Magnaporthe grisea

PWL寄主特异性无毒基因家族是稻瘟病菌无毒基因中一个重要的类群,了解PWL家族成员在稻瘟病菌中的分布和变异对稻瘟病菌群体遗传多样性的研究具有重要价值。研究通过设计23对引物对PWL家族成员进行分布和变异分析,结果筛选到12对引物有特异性扩增结果。扩增结果表明PWL家族基因的主要变异为缺失,试验结果表明,PWL1基因仅存在于牛筋草来源的稻瘟菌菌株中存在,而在分离于水稻的稻瘟病菌中表现为完全缺失;与此相反,PWL2基因则仅在水稻来源的菌株中存在。而插入变异仅存在于部分菌株PWL4基因的上游区域。结果还表明PWL家族成员在稻瘟病菌中具有丰富的的扩增多态性,对稻瘟病菌群体遗传多样性的研究具有重要价值。

PWL gene family belongs to the host-specific resistance avirulence gene, which is an important avirulence gene in Magnaporthe grisea. To understand distribution and variability of PWL family in rice blast fungus was useful for the genetic diversity research of Magnaporthe grisea, however, there was few studies on the distribution and varia- bility of host-specific avirulence PWL family genes in rice blast fungus Magnaporthe grisea. We designed 23 pairs of primers to character the distribution and variability of PWL gene and screened 12 pairs of specific primers of PWL family genes which have specific amplifications. Our results showed that the main mutation mechanism of PWL family genes was deletion. The PWL1 gene existed only in the strains isolated form Eleusine, while the corresponding locus of strains isolated from rice was completely missing; in contrast, PWL2 gene was only in the strain isolated from rice. Insertion mutation existed only in the upstream region of PWL4 gene. Our results suggest that PWL family genes has a rich amplified polymorphic and has a good basis for population genetic diversity analyses.