Studies on the Physiological Response of Brassica chinensis L. Seeds in Germination to Environmental Pollutant LAS Toxicity by FTIR-ATR Spectroscopy

A technique based on Fourier transform infrared attenuated total reflection (FTIR-ATR) spectrometry was used to study the physiological changes in chemical composition of Brassica chinensis L. seeds under a wide range of the alkylbenzene sulphonates (LAS) treatments.The results showed that,after 3d of LAS stress, the absorption bands corresponding to carbohydrates,ester,proteins and protein secondary structure varied differently. The absorption band peaks at 1 632 cm^-1, 1 742cm^-1 which are significantly higher than that of control group (P<;0.05), suggesting the proteins and ester content increased. Fourier self-deconvolution (FSD) analysis result showed that LAS caused the relative ratio of the protein conformation forms as well as α-helix, β-turn and random coil have change. The intensities of carbohydrates absorption bands of radicle and seedling shows different change trends, that shows LAS has different influence on carbohydrate metabolism in radicle and seedling. Furthermore, the band height of FTIR of radicle showed a correlation to the germination percentage, radicle length, inhibition rate of radicle length, Superoxide Dismutase (SOD) activity, Malondialdehyde (MDA) consent. As a result, FTIR-ATR technique can be accepted as rapid and simple way to study the physiological mechanism of plant for adapting the stress of LAS.