response to high-salt stress in Halophyte cells

盐生植物能在高盐环境下生长。为了研究盐生植物细胞对盐胁迫的细胞反应，我们用3种Atriplex植物的细胞进行了培养；将1 entiformis （AL）、halimus （AH）和halimus （AH）分别用和不加0.2M NaCl处理，通过二维电泳分析多肽图谱。经nege /SDS电泳检测，盐处理后的Atriplex细胞不溶性蛋白部分多肽斑点明显增多。SP1的分子质量为27 kDa， pI大于8.5。该多肽为具有Con A结合活性的糖蛋白。LH电泳点洗脱的蛋白用于小鼠抗体制备和n端氨基酸测序。从盐处理的LH细胞中分离mRNA，建立cDNA文库，用探针筛选文库，在n端氨基酸序列构建的引物上进行PCR扩增。我们已经确定了SP1全长cDNA的核苷酸序列，并提交到DDBJ/EMBL/GenBank数据库（AB024338）。还原后的SP1为224-AA， 24 kDa, pI=9.72。在GenBank数据库中，SP1氨基酸序列与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.