| 摘要: |
| 采用非损伤微测技术对不同铁营养状态(正常供铁、缺铁和高铁)下苹果小金海棠(Malus xiaojinensis)水培苗根部镉吸收速率和植株不同部位镉含量进行了测定,并采用半定量RT-PCR研究MxIRT1在不同铁营养状态下的表达变化。结果表明:正常供铁培养条件下,小金海棠根部各区镉吸收速率有明显差异,分生区>伸长区>成熟区;缺铁培养条件下,小金海棠植株根部分生区和伸长区镉吸收速率明显增加,成熟区无明显变化,植株地上部和根部镉积累增加;高铁培养条件下,小金海棠植株根部分生区和伸长区镉吸收速率明显降低,成熟区无明显变化,植株地上部和根部镉积累减少。铁转运蛋白编码基因MxIRT1在不同铁营养状态下表达水平存在明显差异,推测铁营养可能通过调控基因MxIRT1的表达影响重金属镉的吸收。 |
| 关键词: 小金海棠 铁 镉 净吸收速率 非损伤微测技术 |
| DOI：10.11841/j.issn.1007-4333.2011.06.013 |
| 投稿时间：2011-02-28 |
| 基金项目:国家自然科学基金资助项目(30700545); 国家转基因专项课题(2009ZX08009-122B); 北京市科技新星项目(2008B74) |
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| Effect of Fe nutrition status on Cd2+ influx on root surfaceof Malus xiaojinensis |
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GAO Chao, WANG Yi, Ma li, ZHANG Liu-xia, ZHANG Xin-zhong, HAN Zhen-hai
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| (Institute for Horticultural Plants/Key Laboratory of Beijing Municipality of Stress Physiology andMolecular Biology for Fruit Trees, China Agricultural University , Beijing 100193, China) |
| Abstract: |
| The effect of iron nutrition on cadmium influx and accumulation in Malus xiaojinensis plants was studied using a hydroponic system.Net Cd2+ influx to the root was measured at six positions located 0.1mm to 3mm from the root tip using Cd2+ selective microelectrodes.The results showed that net Cd2+ influx decreased with increasing distance from the root tip under normal Fe level condition.In Fe deficiency,the net Cd2+ influx increased markedly in the meristematic zone and elongation zone,but changes in the maturation zone were not obvious,and the concentration of cadmium increased in shoots and roots.However,at high Fe level,the net Cd2+ influx decreased markedly in the meristematic zone and elongation zone,but also changes in the maturation zone were not obvious,and the concentration of cadmium decreased in shoots and roots.Expression studies of the Fe2+ transporter cloned from Malus xiaojinensis,MxIRT1,indicated that the expression of this transporter is distinct at different Fe levels,which might affect the transport of heavy-metal divalent cations such as Cd2+. |
| Key words: malus xiaojinensis Fe Cd2+ net influx non-invasive micro-test technique |
