半夏凝集素基因的克隆、生物信息学分析及其蛋白的亚细胞定位

目的 克隆半夏凝集素基因，并对其进行生物信息学分析和亚细胞定位。方法 以半夏Pinellia ternata新鲜叶片的DNA为模板，根据Genbank上的半夏凝集素的基因序列（GU593718.1）设计引物，克隆了半夏凝集素（PTA）基因，并构建植物表达载体pI1300-CaMV35S-PTA-GFP，在农杆菌GV3101中进行表达且观察了其在烟草中瞬时表达。结果 所克隆的PTA的开放阅读框为810 bp，其编码269个氨基酸；具有1条信号肽、2个B-lectin保守区域和3个甘露糖结合基序；PTA氨基酸序列与NCBI中所报道的半夏、掌叶半夏P. pedatisecta、滴水珠P. cordata凝集素的氨基酸序列的同源性分别达到97%、85%和83%；初步推测其定位于膜上，现已在NCBI中登记（登录号KF154979）。结论 本实验通过对半夏凝集素的生物信息学分析和亚细胞定位分析，为进一步研究半夏凝集素的抗病虫害机制奠定了基础。

Genomic cloning, bioinformatics analysis, and subcellular localization of an agglutinin gene from Pinellia ternata

Objective To clone an agglutinin gene from Pinellia ternata and to analyze its bioinformatics and subcellular location. Methods Based on the published sequence GU593718.1 from Genbank, P. ternata agglutinin (PTA) was amplified and cloned from genomic DNA of the fresh leaves of P. ternata. The cloned PTA gene was further fused to the plant expression vector pI1300-CaMV35S-GFP to construct pI1300-CaMV35S-PTA-GFP, then transfered into cells of Agrobacterium tumefaciens GV3101. Its transient expression was observed in Nicotiana tabacum. Results The full length of PTA contained 810 bp with the deduced 269 amino acid residues; It contained one signal peptide, two conversation B-lectin domains and three mannose binding sites; PTA shared 97%, 85%, and 83% identity with the amino acid sequence from PTA, and Pinellia pedatisecta agglutinin (PPA), Pinellia cordata agglutinin (PCA), respectively; The PTA was localized to the plasma membrane; Its registration number is KF154979 in NCBI. Conclusion It would provide a stable foundation for the study on its effect against fungi, insects, and bacterium.