FTIR结合生理特性研究镉胁迫对果灰藓的影响

Effects of Cd Stress on FTIR Spectra and Physiological Traits of Hypnum fertile Sendtn.

苔藓植物可作为监测环境中重金属污染的指示植物。以苔藓植物果灰藓为实验材料,用不同浓度的重金属镉处理7 d后,借助傅里叶红外光谱法(FTIR)分析重金属镉胁迫下果灰藓各化学成分的变化,同时测定可溶性糖(SS)、可溶性蛋白(Pr)、丙二醛(MDA)含量在镉胁迫下的生理指标。结果表明:随着镉处理浓度的升高,可溶性糖含量和可溶性蛋白含量呈现先上升后下降的趋势,丙二醛含量先下降后上升。FTIR与果灰藓响应重金属镉胁迫的各生理指标变化趋势较一致,且FTIR比传统的生理指标测定更敏感、便捷。因此,FTIR可以作为研究苔藓植物应用于环境重金属污染监测的一种快速、有效的方法。

In the present paper, Fourrier transform infrared spectrometer was applied to gain the infrared spectra of Hypnum fertile Sendm. samples with different concentration of Cd^2＋ for 7 days to study the changes in chemical components, and some physiological characteristics such as malondialdehyde （MDA）, solubility sugar （SS） and solubility protein （Pr） were also studied. Malondialdehyde and solubility sugar were measured by anthrone colorimetry and solubility protein was measured by brilliant blue and commassie dye. The results showed that with the enhancement of Cd^2＋ concentration, the contents of solubility sugar and solubility protein were enhanced at first and then decreased. However, it was just the opposite for the content of malondialdehyde Based on the indices of wave number-absorhance, the infrared spectra of samples with different concentration of Cd^2＋ were compared in terms of changes in the physiological characteristics. The two hands at 2 920 and 2 855 cm^-1 in the CH stretching region （3 000-2 800 cm^-1 ） of the spectra denote the asymmetric and symmetric lipid CH2 stretching vibrations, whose band height＇s variety was related to the change in malondialdehyde content in plant. The distinctive amide- Ⅰ hand at 1 635 cm^-1 and amide-Ⅱband at 1 545 cm^-1 arise from endogenous proteins. In the region below 1 500 cm^-1 , a variety of characteristic IR group frequencies can be observed that are difficult to assign but the shape of the spectra in this region is characteristic and can be used as a ＂finger print＂ of the tissue. The band at 1 036 cm^-1-C-O, -C-C or CH stretching region of the spectra denotes the carbohydrate related to the content of solubility sugar. The results showed that there was good correspondence between the changes in the physiological characteristics and the changes of samples based on the indices of wave number-absorhance of FTIR spectra, and the FTIR was more sensitive and convenient. Therefore, Fourrier transform infrared spectrometry can be accepted as a fast and effective method to study bryophytes for monitoring the pollution degree of heavy metal in environment.