[FTIR spectroscopic characterization of chromium-induced changes in root cell wall of plants]

Due to its wide industrial use, chromium is considered a serious environmental pollutant. Contamination of soil and water by chromium (Cr) is of recent concern. Chromium mainly accumulates in root in plants, and the change in compounds of the root cell wall have a close relation with the Cr accumulation. Compared with the other identification methods, the identification of the Chinese traditional and herbal drugs using Fourier transform infrared spectrometer with OMNI collector is simple and convenient, fast and accurate. In the present paper, the spectra of cell wall of Cr-treated root and control of Eichhornia crassipes and Alternanthera philoxeroides were determined. Absorption peaks were identified to the corresponding functional groups and half-quantitative analysis was also used. The results showed that a significant shift of -OH absorption peaks can be seen when comparing the FTIR spectra of control and Cr-treated plants, and the absorbency of -OH and COO- groups went up in E. crassipes root cell wall while droped in A. philoxeroides root cell wall. It is suggested that -OH and COO groups were referred in binding Cr6+ in aqueous solutions, and this may be included in the mechanism of Cr accumulation in E. crassipes roots. Therefore, FTIR spectrometry could be widely used to monitor changes in chemical composition of plant parts under stresses and environmental restoration.