Changes in the chemical properties and swelling coefficient of alfalfa root cell walls in the presence of toluene as a toxic agent

Abstract

The influence of toluene pollution on the chemical properties and swelling coefficient of root cell walls in alfalfa (Medicago sativa L.) was investigated. Two sets of alfalfa seedlings were selected and one set was treated with 450 mg L(-1) toluene in the nutrient solution under hydroponic culture. Thirty days after treatment with toluene, alfalfa plants were harvested and the root cell walls were isolated. Fourier-transform infrared (FTIR) spectroscopy was carried out for the characterization of the root cell walls composition. The cation exchange capacity (CEC) and the swelling coefficient of the root cell walls (Kcw) were estimated at various pH values. The toluene contamination significantly reduced the mass of the cell wall material in the alfalfa roots. According to the FTIR spectra, the toluene pollution can change the alfalfa root cell wall properties by reducing the cell wall functional groups. These functional groups are probably related to the proteins and polysaccharides in the cell wall. Also, toluene pollution strongly reduced CEC and Kcw of the root cell walls. The results show that the decrease in the active sites of adsorption on the root cell walls as a response to toluene pollution can affect the water flow rate and the mineral nutrients uptake by roots.

More negative charges on roots enhanced manganese(II) uptake in leguminous and non‐leguminous poaceae crops

“…4 show absorption bands at 1628, 1542, and 1240 cm −1 that were assigned to antisymmetric stretching vibrations of carboxyl, N H bending vibrations, C N stretching, and N H bending vibrations in the amide I, II, and III, respectively. 18,25 The absorption band at 1021 cm −1 was attributed to the C-OH bending vibrations in carbohydrates 30 and the bands at 1372 and 1317 cm −1 were attributed to cellulose CH 2 stretching, 31 whereas that near 1411 cm −1 was assigned to symmetric -COO − stretching. 32 There were similar functional groups on the legume and non-legume poaceae roots.…”

“…17 There are many functional groups, such as -COOH, -OH, and -H 2 PO 4 on plant roots and their dissociation produces negative charges on the root surface, which induces electrostatic adsorption of metal ions onto plant roots. [18][19][20] Numerous studies have been carried out on the electrochemical properties of cell walls and plasma membranes of plant roots, and on how they affect the uptake of nutrient elements and toxic metals. 21,22 These studies suggest that the phytotoxicity of metal ions was mainly determined by the surface charge of plant roots.…”

Iron Plaque Prevents Partitioning of Polycyclic Aromatic Hydrocarbons on Rice (Oryza sativa) Root Surface

“…The spectra of rice root biosorbents with and without Fe plaque appeared to be similar, revealing that the influence of the DCB method on root organic material could be neglected during Fe plaque removal. The only difference in spectra between rice root with and without Fe plaque was the disappearance of absorption at 1635 cm –1 arising mainly from the C=C linkage in the aromatic ring (Sharifi et al 2016), and at 465 and 532 cm –1 arising mainly from the C–C linkage in carbohydrate, C–H linkage in aromatic ring, or the variable angle vibration of O–H (Gauthier et al 2005). The DCB method has been widely employed to remove Fe plaque from root surfaces, although this method may influence the stability of organic matter in some degree (Sakee et al 2009).…”

Morphological effect of dichloromethane on alfalfa (Medicago sativa) cultivated in soil amended with fertilizer manures

“…The plant grown in DCM spiked soil exhibited a more significant reduction in shoot length than in manures spiked soil. Also, the root length was significantly reduced in comparison with the solvent-free control treatment (Sharifi et al 2016).…”

“…The inhibitory effects were more pronounced with the highest dose of DCM. Sharifi et al (2016) have shown that the toluene concentration of 450 mg L À1 has caused significant detrimental effects on the root growth of alfalfa plants.…”