选择耐铝性不同的2个大豆品种浙春2号(耐铝性)和浙春3号(铝敏感)作为实验材料,在设置铝胁迫的同时添加外源柠檬酸处理,应用傅里叶变换红外光谱法(FTIR)对外源柠檬酸协同铝胁迫下的大豆根组织干燥粉末进行直接测定,并对其特征吸收峰进行了归属。通过对各图谱的比较分析,铝处理下大豆根的红外吸收峰形及峰强有所区别,特别是1 057,1 602,2 927和3 297 cm^-1左右的吸收峰区别明显,反应出蛋白质,糖类以及核酸等有机物的含量变化;以A2 927 cm^-1/A3 297 cm^-1为横坐标、A1 051 cm^-1/A1 602 cm^-1为纵坐标而绘制的二维分析图显示,外源柠檬酸的加入使不同处理的红外吸收峰形及峰强差异降低,意味着有机物等有效成分的变化不显著,且浙春3号尤为明显。实验表明FTIR在某种程度上能够反映外源柠檬酸对铝胁迫下大豆根的缓解效应,为该领域的研究工作提供了有益的参考。

In the present study,19 soybean (Glycine max L.) cultivars were analyzed and found to differ considerably in aluminum (Al) resistance.The cultivars Zhechun No.2 (Al-resistant) and Zhechun No.3 (Al-sensitive) were selected for further analysis.Experiments were performed with plants grown in full nutrient solution for 30 days.Fourier transform infrared spectrometry (FTIR) with OMNI-sampler was applied to the direct determination of different varieties of soybean root tissues,treated with aluminum in a dose-and time-dependent manner plus exogenous citric acid.Then the characteristic absorption peaks of spectra were analyzed and some differences in the FTIR spectra among samples were found from the comparison of the spectra.Results showed that the intensity and the shape of absorption peaks of their FTIR spectra exhibited some differences between different kinds of soybean and different treatment,especially around 1 057,1 602,2 927 and 3 292 cm^-1,which mainly reflected the content variety of protein,glucide,nucleic acid and so on.Thus it could be concluded that the effect of aluminum stress and existence of exogenous citric acid did not change the component of chemical substance in soybean roots,although the content of certain substance varied.The two dimensional discriminates analysis chart was drawn by the ratio of area at 2 927 cm^-1 to that at 3 297 cm^-1 as the abscissa vs the ratio of area at 1 057 cm^-1 to that at 1 602 cm^-1 as the vertical,to discover the difference between the treatment of aluminum plus exogenous citric acid and that of single aluminum.Result indicates that the difference in the shape of absorption peaks of FTIR spectra became smaller and that presumed the content variety with different treatment was not remarkable under the condition of exogenous citric acid,especially in Zhechun No 3.From all mentioned above it is made clear that exogenous citric acid could really ameliorate distinctly the effect of aluminum on soybean roots which was detected by direct determination of FTIR spectrum,giving the fact that FTIR could reflect the ameliorating effect of exogenous organic acid on plant tissue under aluminum stress.