空心莲子草铵转运体ApAMT1;3基因的克隆及功能鉴定

Cloning and identification of ammonium transporter ApAMT1;3 from the aquatic weed Alternanthera philoxeroides

近年来,空心莲子草(Alternanthera philoxeroides)因其对水体富营养化尤其是水体铵积累有潜在的修复能力而受到人们的关注。然而,目前对空心莲子草吸铵的分子生物学研究甚少。本研究利用简并引物和RACE技术分离了一条铵转运体cDNA,命名为ApAMT1;3;实时定量结果表明,ApAMT1;3主要在地上部表达,缺铵处理显著增强了ApAMT1;3在根、茎及叶部的表达水平;酵母功能互补试验表明,ApAMT1;3是一个功能型的铵转运体。本研究结果为研究空心莲子草NH4+的吸收和利用提供了新的基因资源,同时也为研究水生植物NH4+的吸收转运及调控机制奠定了分子生物学基础。

Alligatorweed(Alternanthera philoxeroides)has been recently investigated for its potential capability of phytoremediation of water eutrophication,especially for the accumulation of ammonium(NH4+)nutrient pollutes.However,molecular studies towards NH4+uptake is largely unclear in this plant.In this study,we successfully isolated an NH4+transporter cDNA,named ApAMT1;3,using degenerated primers and rapid amplification of cDNA end(RACE)techniques.Quantitative real-time PCR(qRT-PCR)showed that ApAMT1;3 was majorly expressed in shoots,and the transcript levels were significantly enhanced in all tested organs,including roots,stems and leaves by NH4+starvation of ApAMT1;3.Functional complementation of yeast mutant showed that ApAMT1;3 can mediate external NH4+uptake.This study directly provide new gene resource to reveal NH4+uptake and utilization of alligatorweed,and favorably help to investigate the mechanisms underlying NH4+uptake and transport in aquatic plants.