利用抑制差减杂交技术，分别构建小麦幼苗在水分胁迫1 h、6 h、12 h、24 h和48 h条件下的cDNA文库，得到6 733条EST序列。通过对这些序列的组装、比对、注释和分类，初步构建了小麦不同水分胁迫条件下的应答基因表达谱，发现水分胁迫应答基因表达的时间特性及4种表达模式。在648个已知功能注释的uni-gene中，6.17%属转录因子类基因，2.16%为蛋白磷酸酶类基因，4.01%是蛋白激酶类基因，19.90%为避免损伤和修复蛋白类基因，2.0%为大分子保护因子类基因，9.11%为膜蛋白类基因，这些基因可能是抗旱相关的重要基因。
To understand the gene expression characteristics, which involved in drought tolerance, five cDNA libraries were constructed using suppression subtractive hybridization (SSH) method with wheat seedlings sampled at 1, 6, 12, 24 and 48 hours of water stress, respectively. By sequencing, 6 733 ESTs were obtained from the cDNA libraries. The gene expression profile induced by water stress in wheat seedling has been preliminarily constructed after assembling, homologous comparing, annotating and classifying the EST sequences. The dynamic characters and 4 patterns of gene expression during water stress treatment were found. The expression pattern 1 in which the most genes were detected at the initial stage, but the number of genes decreased to the least at 12th hour of water stress, then gradually increased with water stress undergone continuously, included genes involved in repair and protection from damage. The pattern 2 with the fewer genes at the initial stage, but the gene number increased-decreased-increased gradually with the water stress process of time, which was protein synthesis-related genes. The pattern 3 was that gene number was fewer at the initial stage, but gradually increased to the most at 12th hour, then gradually decreased, such as protein kinase gene. Number of genes in the pattern 4 was higher at the initial stage, and then decreased-increased-decreased gradually along with the water stress elongation, to which protein phosphatase gene belongs. Among 648 uni-genes of known function annotation, the proportion of transcription factor genes was 6.17%, protein phosphatase genes 2.16%, protein kinase genes 4.01%, genes involved in repair and protection from damage 19.90%, genes of macromolecule protection factor 2.0%, membrane protein genes 9.11%, which may be important gene classifications related to drought resistance. The result was helpful to completely comprehend genetic mechanism of drought resistance in wheat, to discover and utilize key genes in the improvement of crop drought resistance.
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