Effect of exogenous amino acids on Cu uptake and translocation in maize seedlings

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• 作者：Zhigao Zhou ; Jianmin Zhou ; Renying Li ; Huoyan Wang and Jinfang Wang
• 关键词：Amino acids ; Cu translocation ; Cu uptake ; Maize ; Oxidation state
• 刊名：Plant and Soil
• 出版年：2007
• 出版时间：March, 2007
• 年：2007
• 卷：292
• 期：1-2
• 页码：105-117
• 全文大小：397 KB
• 刊物类别：Biomedical and Life Sciences
• 刊物主题：Life Sciences
  Plant Sciences
  Soil Science and Conservation
  Plant Physiology
  Ecology
  
• 出版者：Springer Netherlands
• ISSN：1573-5036

文摘

This study aimed to assess the effects of four contrasting proteinogenic amino acids on copper (Cu) uptake and translocation in maize (Zea mays L.) seedlings grown in a modified Hoagland solution. Glycine, aspartic acid and lysine at three concentrations (10, 25 and 100 μM) did not have any significant effect on Cu uptake and translocation in maize seedlings over a two-day experimental period. However, cysteine (a reductive amino acid) at the three concentrations increased very significantly (P < 0.01) Cu accumulations in the root symplast and the shoots of maize seedlings in comparison to the control. Cu uptake in the whole plant and Cu translocation from root to shoot were also increased in the cysteine treatments. In the 25 μM cysteine treatment, where cysteine was in moderate excess, the Cu uptake in the whole plant and Cu translocation from root to shoot were significantly (P < 0.01) higher than those of the 10 or 100 μM cysteine treatments, where the concentration of cysteine was equivalent to that of Cu(II) or in great excess according to the stoichiometry of the redox reaction of cysteine with Cu(II). It is hypothesized that the cysteine-induced oxidation state alteration from Cu(II) to Cu(I) could be responsible for the increased Cu uptake and Cu translocation, on the ground that Cu(I), as free cuprous ion or cysteine cuprous complex, may be more available to maize roots than Cu(II).