铁蛋白超表达增强水稻的铁胁迫耐受性研究

采用溶液培养法,对铁蛋白(ferritin)超表达水稻植株进行过量Fe2+(150mg/kg,250mg/kg)胁迫处理,测定其苗高、生物量、叶绿素含量及质膜透性。结果表明,铁胁迫条件下,供试植株生长受到明显抑制,苗高和生物量下降、叶绿素含量减少、质膜透性增加。胁迫组中,转基因植株苗高下降21%,地上部和根系干重分别下降41%和11%,叶绿素含量下降21%,质膜透性增加50%;非转基因植株苗高下降41%,地上部和根系干重分别下降65%和70%,叶绿素含量下降60%,质膜透性增加99%。相比之下,转铁蛋白植株生长受铁胁迫影响较小,其苗高、生物量、叶绿素含量、质膜透性变化幅度均比对照小。由此可见,铁蛋白超表达减轻了过量Fe2+对植株叶绿素含量的影响和对叶片质膜的损伤,从而缓解了铁胁迫对植株生长的抑制作用,增强了水稻植株的铁胁迫耐受性。

The Improved Tolerance to Fe2+ Stress in ferritin overexpression rice

To find out if the ferritin overexpression rice plants hold the enhanced tolerance to excessive Fe2 stress,the plant height,biomass,iron content,chlorophyll content and membrane permeability were determined from the ferritin transformed lines grown in nutrient solution with 150mg/kg and 250mg/kg Fe2 ,with the non-transgenic rice line Xiushui11 as control.The results indicated that all the tested plants under Fe2 stress showed retarded growth,decreased biomass and chrolophyll content,and increased membrane permeability.Under excessive Fe2 condition,the plant height,shoot DW,root DW and chlorophyll content of transgenic plants decreased by 21%,41%,11% and 21%,respectively,and membrane permeability increased by 50%,while the plant height,shoot DW,root DW and chlorophyll content of non-transgenic plants decreased by 41%,65%,70% and 60% respectively,and membrane permeability increased by 99%.Compared with control,the ferritin transformed lines were less influenced by iron stress and showed higher plant height,biomass,chlorophyll content and lower membrane permeability.Evidently,the ferritin overexpression decreased the influence of excessive Fe2 stress on the plant growth and chlorophyll content of rice and the injury to membrane.In other words,the overexpression of ferritin gene is effective in improving the endurance of rice plants to excessive Fe2 stress.