商陆高亲和性K^+转运体基因PaHAK1的克隆与表达分析

Cloning and Expression Analysis of High-Affinity Potassium Transporter Gene PaHAK1 from Phytolacca acinosa Roxb.

为了研究高钾植物商陆高亲和性K+吸收机制,本试验选用野生商陆为材料,以拟南芥、冰叶日中花、小麦、大麦和水稻等多种植物的HAK家族基因的保守序列,设计简并引物,获得了981bp的PaHAK1的基因片段。然后应用RACE技术克隆到PaHAK1基因序列,其cDNA全长为2337bp,编码771个氨基酸。该编码蛋白质分子量为86.66kDa,等电点为7.54。蛋白质疏水性和拓扑结构分析显示该氨基酸序列共有12～13个跨膜区。该cDNA序列与冰叶日中花HAK1基因序列相似性高达88%。Real-Time PCR分析表明PaHAK1主要在商陆根中表达,低钾状态可以诱导PaHAK1的高表达。

To study the mechanism of high affinity potassium absorption in some high-K plants, the PaHAK1 cDNA fragment of 981 bp sequences was cloned from wild Phytolacca acinosa Roxb. by polymerase chain reaction with degenerate primers designed according to conserved HAKs cDNA sequences of Arabidopsis thaliana, Mesembryanthernum crystallinum, Triticum aestivum, Hordeum vulgare and Oryza sativa. The fulllength cDNA sequences of PaHAK1 was 2 337 bp which was isolated with rapid amplification of cDNA ends method. The deduced protein was 771 amino acids with molecular weight 86.66 kDa and isoelectric point 7.54. Hydrophobicity plot and topology prediction results indicated the protein had 12-13 putative transmembrane regions. Blastn results showed it was 88% homology to HAK1 of Mesembryanthemum crystallinum. The Real- Time PCR results showed the PaHAK1 was mostly expressed in root of the plant and it could be induced in the low potassium condition.