Reddy P M, Kouchi H, Ladha J K
International Rice Research Institute, P.O. Box 933, 1099 Manila, Philippines.
Biochim Biophys Acta. 1998 Dec 22;1443(3):386-92. doi: 10.1016/s0167-4781(98)00232-2.
Rice (Oryza sativa var. Nipponbare) possesses two different homologues of the soybean early nodulin gene GmENOD93 (GmN93). Analysis of the cDNA clones of rice homologues showed that OsENOD93a has an open reading frame (ORF) with a coding sequence homology of 58.2% to GmENOD93, whereas the ORF of OsENOD93b has displayed a homology of 42.3%. OsENOD93a and OsENOD93b genes are differentially expressed in different parts of the rice plant, as well as in cultured cells induced or non-induced with chitin oligomer. In intact rice tissues, OsENOD93b was most abundantly expressed in roots and at much lower levels in etiolated and green leaves, whereas the expression of OsENOD93a was very low in roots and etiolated leaves, and was not detected in green leaves. The level of OsENOD93a expression was enhanced markedly in suspension-cultured cells, whereas that of OsENOD93b did not increase. The application of chitin oligomer, an elicitor which induces a defence response in plants, did not significantly alter the expression of both these homologues in suspension cultures.
水稻（日本晴品种）拥有大豆早期结瘤素基因GmENOD93（GmN93）的两种不同同源基因。对水稻同源基因的cDNA克隆分析表明，OsENOD93a具有一个开放阅读框（ORF），其编码序列与GmENOD93的同源性为58.2%，而OsENOD93b的ORF同源性为42.3%。OsENOD93a和OsENOD93b基因在水稻植株的不同部位以及用几丁质寡聚物诱导或未诱导的培养细胞中差异表达。在完整的水稻组织中，OsENOD93b在根中表达最为丰富，在黄化叶和绿叶中的表达水平则低得多，而OsENOD93a在根和黄化叶中的表达非常低，在绿叶中未检测到。OsENOD93a在悬浮培养细胞中的表达水平显著提高，而OsENOD93b的表达水平没有增加。几丁质寡聚物作为一种能诱导植物防御反应的激发子，其应用并未显著改变悬浮培养物中这两种同源基因的表达。
