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采用改进的差异显示方法由稻瘟菌激发子处理的水稻悬浮培养细胞中得到７个诱导表达的蛋白激酶 ｃＤＮＡ 片段。为获得这些蛋白激酶的编码全长序列，构建了稻瘟菌激发子处理的水稻细胞ｃＤＮＡ 文库。以上述一个 ｃＤＮＡ 片段作为探针筛选文库，得到一个含有完整阅读框的 ｃＤＮＡ 克隆ＯｓＥＰＫ１。分析ＯｓＥＰＫ１的推定氨基酸序列的结果表明：它由Ｎ 端信号肽、胞外区域、跨膜结构和胞内蛋白激酶结构域等几部分组成，可能为一受体类似蛋白激酶。对比 ＯｓＥＰＫ１与其它植物受体类似蛋白激酶在胞外区域的相似性，结果显示ＯｓＥＰＫ１与小麦叶锈激酶家族同源性较高，推测它们可能属于同一类植物受体类似蛋白激酶。此外，ｎｏｒｔｈｅｒｎ 杂交显示，ＯｓＥＰＫ１可由稻瘟菌激发子迅速瞬时诱导，因而它的诱导可能也是水稻对稻瘟菌侵染做出的一种早期防卫反应。
Seven modified protein kinase cDNA fragments were obtained from rice suspension culture cells treated with the rice blast elicitor using the improved differential display method. To obtain full-length coding sequences for these protein kinases, a rice cell cDNA library of M. grisea elicitor was constructed. The library was screened using the above cDNA fragment as a probe to obtain a cDNA clone OsEPK1 containing the complete reading frame. Analysis of putative amino acid sequence of OsEPK1 showed that it consists of N-terminal signal peptide, extracellular domain, transmembrane structure and intracellular protein kinase domain, which may be a receptor-like protein kinase. Comparing the similarity between OsEPK1 and other plant receptor-like protein kinases in the extracellular region, OsEPK1 showed high homology with the wheat leaf rust kinase family, suggesting that they may belong to the same class of plant receptor-like protein kinases. In addition, northern hybridization showed that OsEPK1 can be rapidly and transiently induced by the rice blast elicitor, and its induction may also be an early defense response to rice blast infection.