response to high-salt stress in Halophyte cells

盐生植物能够在高盐环境中生长。为了研究盐生植物细胞对盐胁迫的响应，对三种滨藜(1)、滨藜(AH)和滨藜(AH)的培养细胞分别进行了0.2M和不同浓度的盐胁迫处理，并用双向电泳法分析了细胞内的多肽图谱。经盐处理的滨藜细胞经盐处理后，其不溶性蛋白质组分中的多肽斑点明显增多。其中一种多肽命名为SP1，其相对分子质量为27 kDa，等电点大于8.5。该多肽是具有刀豆蛋白A结合活性的糖蛋白。从黄体生成素的电泳点洗脱出的蛋白用于小鼠抗体的制备和N端氨基酸序列测定。从盐处理的黄体细胞中提取mRNA，制备文库，以N-端氨基酸序列为模板，通过PCR扩增探针进行文库筛选。我们已经测定了SP1的全长cDNA的核苷酸序列，并提交到DDBJ/EMBL/GenBank数据库(AB024338)。还原的氨基酸序列表明，SP1为224-aa，24 kDa，等电点为9.72。在GenBank数据库中搜索SP1的氨基酸序列，结果显示与Germin和草酸氧化酶相似。

Halophyte plants are able to grow under high saline environments. For examining cellular response of Halophyte cells to salt stress, cultured cells from 3 Atriplex species ; 1 entiformis (AL), halimus (AH) and halimus (AH) were treated with and without 0.2M NaCl, and polypeptide patterns were analyzed by 2-D electrophoresis. Significant increase of polypeptide spot were detected in insoluble protein fractions of salt treated Atriplex cells on NEPHGE/SDS electrophoresis. A polypeptide named SP1 was with a molecular mass of 27 kDa with pI over 8.5. The polypeptide was glycoprotein with Con A binding activity. Eluted proteins from electrophoretic spot of LH were used for antibody preparation by mice and N-terminal amino acid sequencing. mRNA were isolated from salt-treated LH cells and cDNA library was prepared, and library screening were done using a probe, which amplified by PCR on primers constructed from N-terminal amino-acid sequences. We have determined the nucleotide sequence of a full length cDNA for SP1 and submitted on the DDBJ/EMBL/GenBank databases (AB024338). Reduced amino acid sequences reveals that SP1 is 224-AA, 24 kDa and pI=9.72. A search of the GenBank data base for SP1 amino acid sequence showed similarity to Germin and oxalate-oxidase.