中文摘要：

Wap25是从桑树幼茎克隆的低温诱导蛋白基因，为胚胎后期富集蛋白（LEA）基因的成员之一，与其它物种低温诱导基因的同源性很低。生物信息学分析表明，桑树低温诱导基因Wap25编码蛋白由226个氨基酸组成，分子质量25．3kD，等电点5．52；蛋白N端1—30位氨基酸表现出强烈的疏水性，其后是亲水性高的区域，平均亲水值达-1．020，而蛋白1—29位氨基酸为典型的真核生物蛋白质的信号肽序列，表明WAP25蛋白属于分泌型蛋白。用SubLocv1．0软件预测WAP25的亚细胞定位，将该蛋白定位于细胞质中。Tmpred软件预测WAP25不存在跨膜结构。构建Wap25与绿色荧光蛋白（GFP）的重组质粒，用基因枪法将其转入洋葱表皮细胞，在激光扫描共聚焦显微镜下发现GFP分散于洋葱表皮的细胞质中，而在细胞核未发现GFP的表达，此结果与wAP25的亚细胞定位预测结果相符。

英文摘要：

Wap25 gene, which belongs to the late embryogenesis .abundant （LEA） family, was cloned from young stem of mulberry. The alignment analysis showed that this gene had very low identities with cold-induced genes in other species. Bioinformatics analyses indicated that Wap25 encodes a 226 amino acid protein with a theoretical molecular mass of 25.3 kD and a pl of 5.52. Its N-terminal amino acids 1 to 30 have strong hydrophobicity. The following amino acids are highly hydrophilic, with an average hrdrophilicity score of -1. 020. The N-terminus contains a typical signal peptide of eukaryotic proteins with a putative cleavage site located after position 29, suggesting that WAP25 is a secreted protein. Subcellular localization prediction with SubLocv 1.0 program indicated that WAP25 was located in cytoplasm and prediction with Tmpred software revealed that WAP25 had no transmembrane domain. A green fluorescent protein （GFP） fusion recombinant protein expression vector was constructed and transformed into onion epidermal cells by biolistic meth- od. Observation under laser scanning confocal microscope showed that GFP was disseminated in the cytoplasm of onion epidermal cells and no signal was found in nucleus, being consistent with the predicted result of subcellular localization.