从柚子 (Citrus grandis Osbeck) 2个自交不亲和品种溪蜜柚和度尾蜜柚的花柱中克隆出一个类似 S核酸酶基因 Cg SL1(C.grandis S- like RNase) ,它的 c DNA序列全长 10 74 bp,编码 2 97个氨基酸。通过与其它植物S- like核酸酶和 S核酸酶氨基酸序列进行比较 ,发现 Cg SL1类似于 S- like核酸酶 ,与拟南芥中的 RNS2一致性为6 2 .5 %。对 Cg SL1的表达分析表明该基因在花柱、花药、叶片不同器官以及花柱的不同发育阶段均有表达 ,且在花柱中的表达随衰老增强 ,由此推测它可能与衰老有关。 A similar C nuclease gene Cg SL1 (C. grandis S-like RNase) was cloned from the two self-incompatible varieties Citrus grandis Osbeck, The DNA sequence is 1074 bp in length and encodes 2 97 amino acids. By comparing with the S-like nuclease and S nuclease amino acid sequences of other plants, Cg SL1 was found to be similar to S-like nuclease and had a consistency with RNS2 of 62.5% in Arabidopsis thaliana. The expression analysis of Cg SL1 showed that the gene was expressed in different developmental stages of style, anther, leaf organ and style, and the expression in the style increased with aging, suggesting that it may be related to aging.