荒漠植物花棒耐盐性的傅立叶红外光谱法研究

 试验以荒漠植物花棒幼苗为材料,应用傅立叶红外光谱（FTIR）法研究了NaCl胁迫下花棒叶片主要有机化合物含量和蛋白质结构的变化以及叶片K+和Na+含量。结果表明,叶片Na+、K+含量随着0~255 mM NaCl盐胁迫逐渐增强而变化,导致Na+/K+比值逐渐降低,显示出盐胁迫下花棒幼苗具有”吸钾排纳”特性。花棒幼苗再170 mM NaCl的高浓度胁迫下24 h,叶片中蛋白质、酯类和碳水化合物含量大幅度增加。花棒的蛋白质二级结构中1 665/1 638 cm-1比值的逐渐降低。揭示出花棒植株通过增强蛋白质、酯类和碳水化合物合成代谢调控能力抵御盐胁迫的损伤,而且花棒蛋白质二级结构更趋稳定,与叶片中Na+/K+比值的变化趋势显著相关。因此花棒为了适应高浓度盐胁迫,具有叶片蛋白质、酯类快速合成以及蛋白质构象更趋于稳定的积极响应。

Study on Salt Tolerance of Desert Hedysarum Scoparium Seedling by Fourier Transform Infrared Spectrometry

A technique based on Fourier Transform Infrared Spectrometry (FTIR) was developed to detect the corresponding changes in chemical composition of Hedysarum scoparium seedlings associated with the rapid changes of Na+ and K+ content in NaCl stress. The result showed that the content of K+ increased with the increasing NaCl stress, but the Na+ content decreased. In 24 hours of high salt stress (170 mM NaCl), the intensities of ester, fingerprint and amide I absorption bands area increased, meaning that the cell lipid, carbondioxide and protein synthesis continued increasing in Hedysarum scoparium seedlings. The analysis of the ratio between 1 665/1 638 cm-1 in amide I absorption bands revealed that Hedysarum scoparium seedling was able to maintain a higher-ordered form of proteins second structure under salt stress. Furthermore, the changes in protein conformation showed a positive correlation to the leaf Na+/K+ ratio in Hedysarum scoparium seedling leaves.