Manganese Stress on Chemical Composition of Chenopodium ambrosioides L. by FTIR Spectroscopy

Fourier transform infrared was used to investigate physiological changes in the chemical composition of roots, stems and leaves of Chenopodium ambrosioides L. amended with different manganese concentrations(5, 200, 500, 2000, 5000, 10000 μmol/L) in nutrient solutions. The absorption band heights at 3350 cm^-1 and 1642 cm^-1 of stem tissues first increased and then decreased, which indicated that the exudation and transportation of organic substances serve as organic osmotic contents to enhance Mn tolerance under low Mn treatments. Moreover, the band heights at 2926 cm^-1 of roots which have different tendencies in accordance with Mn treatments showed that the capability of chelating Mn decreased at higher Mn treatment levels. In addition, the changes of the bands at 1060 cm^-1 differ from each other, suggesting that under the condition of severe Mn stress, the per oxidation of membrane lipid increased. All the results imply that it is practical to apply FTIR to explore the physiological mechanism of metal tolerance in higher plants.