水稻金属硫蛋白基因(rgMT)遗传转化的紫花苜蓿耐盐性分析

采用根癌农杆菌介导法将从水稻(Oryza sativa)中克隆出的一个金属硫蛋白基因(rgMT)转化到紫花苜蓿(Medicago sativa)品种"农菁1号"中,经PCR和Northern blot技术对获得的抗性植株进行了检测,证明rgMT基因已整合到苜蓿基因组中并在转基因植株中转录表达。以野生型苜蓿为对照,对获得的转基因苜蓿株系在不同浓度NaCl、NaHCO3胁迫下的表型和生理指标测定发现,NaCl、NaHCO3胁迫处理后,野生型苜蓿受胁迫严重甚至死亡,转基因苜蓿受胁迫较轻。转基因苜蓿的脯氨酸含量和超氧化物歧化酶活性显著高于野生型(P0.05),细胞膜透性显著低于野生型,野生型苜蓿叶片中积累的过氧化氢高于转基因苜蓿的叶片中积累的过氧化氢。研究结果表明,rgMT基因已在苜蓿中表达,并且提高了转基因苜蓿的耐盐性。

Salt stress tolerance analysis of rgMT gene transformed Medicago sativa

In this study,a metallothionein gene (rgMT)cloned from rice was transformed into Medicago sati-va cv."Nongjing No.1"using the Agrobacterium-mediated method.Resistant seedlings were tested by PCR and northern blotting,and the results showed that rgMT gene was transformed into M.sativa genome,and was normally expressed in transgenic plants.We compared the phenotypic traits and physiological characteris-tics of the non-transgenic line (wild-type,WT)and transgenic lines under different concentrations of NaCl and NaHCO3.The growth of the WT was inhibited severely,and even death was observed,but the transgenic lines were j ust slightly inhibited.The proline and superoxide dismutase (SOD)contents of the transgenic lines were significantly higher than those of the WT (P<0.05),and the relative membrane permeability of the transgenic lines were significantly lower than those of the WT under salt stress.More H2O2accumulated in the leaves of the WT compared to in those of transgenic lines.This result showed that rgMT was expressed in M.sativa, and the transgenic lines had a greater salinity tolerance than the WT.