差异显示法分离水稻抗稻瘟病相关基因

采用mRNA差异显示技术，分析水稻稻瘟病抗源材料“地谷”叶片受稻瘟病菌侵染前后的基因的表达差异，获得87个差异片段。对这87个差异片段进行了回收、重扩增与克隆，并对其中的81个片段进行了杂交鉴定。斑点杂交结果证实其中6个片段受稻瘟病菌诱导表达。进一步克隆测序并进行数据库比对分析表明其中一个与水稻4号染色体中一推测的苹果酸合成酶高度同源，一个与水稻11号染色体上的RPR1基因高度同源，RPR1基因具有保守的NBS-LRR结构，并与水稻防卫反应的信号传导有关；另一个与水稻第6号染色体上一推测的硫氧还蛋白高度同源，其余3个为新的cDNA片段。

Identification of Genes Related to Resistance to Magnaporthe grisea Using Differential Display Technique in Rice

Rice blast caused by Magnaporthe grisea is one of the most serious constraints on high productivity.Understanding the mechanism of the infection of Magnaporthe grisea and the change of gene expression after infection is useful to control blast disease in rice.This work presents the isolation of differentially expressed cDNA fragments from rice leaf induced by the inoculum suspension of Magnaporthe grisea using mRNA differential display technique.Total 87 differential expressed cDNA fragments were recoveried and reamplified.The dot-blotting results showed that 6 fragments of 81 were confirmed to be the expression induced by Magnaporthe grisea inoculum.Those fragments were then cloned into vectors for sequencing.Sequence analysis through Internet Blast searching showed that 3 fragments were novel gene fragments.One was homologous with a putative malate synthase gene on rice chromosome 4 with 78% identities of amino acid;one was highly homologous (75% identity) with rice RPR1 gene on chromosome 11,which has a conservative structure of NBS-LRR domain and may be related to signal transduction of rice defense reaction;another one was homologous with a putative thioredoxin gene on rice chromosome 6 with the identity of 72%.