半夏凝集素基因的克隆与氨基酸序列初步分析

目的 克隆半夏凝集素基因并对其氨基酸序列生物信息与已报道相关基因进行对比分析，为抗虫基因利用和转基因育种研究奠定基础。方法 根据已报道的植物凝集素基因序列设计特异引物，以半夏叶片DNA为模板进行PCR扩增，获得特异性片段，将其连接到测序载体上，进行序列测定，用分析软件分析序列信息。结果 克隆1 069 bp的半夏凝集素基因(pta)，开放阅读框全长804 bp，编码268个氨基酸残基；预测相对分子质量和等电点分别为2.91×10⁴和7.77，功能区完整，具有1条信号肽和3个甘露糖结合区；已在GenBank中登记（登录号AY725425）。结论 克隆的半夏凝集素基因序列信息完整，具有典型的甘露糖结合位点，可以作为抗虫基因用于抗虫育种。

Cloning of Pinellia ternata agglutinin gene and analysis on its amino acid sequence

Objective To clone Pinellia ternata agglutinin (PTA) gene, compare its amino acid sequence and bioinformation with former reported genes, and lay the foundation for utilization of insect-resistant gene and transgenic breeding. Methods Based on the specific primers designed by reported plant lectin gene sequence, DNA extracted from P. ternata leaves was taken as template to amplify PCR and a specific fragment was obtained which was linked to the sequencing vector for being sequenced and their information was analyzed using analytical software. Results A full-length nucleotide sequence of pta with 1 069 bp was cloned (AY725425 in Genbank). The full length of open reading frame (ORF) was 804 bp encoding 268 amino acids residue. The predicted relative molecular weight and isoelectric point (PI) were 2.91 × 10⁴ and 7.77, respectively. The functional section was intact with a signal peptide and three mannosebinding sites. Conclusion The cloned pta gene is intact with typical mannosebinding sites and could be used as insect-resistant gene for insect-resistant breeding.