Cadmium induction of lipid peroxidation and effects on root tip cells and antioxidant enzyme activities in Vicia faba L.

Abstract

The effects of different concentrations (1-50 microM) of Cd on root growth, cell division and nucleoli in root tip cells, protective enzyme activities and lipid peroxidation in Vicia faba were investigated in order to better understand the processes of Cd-induced senescence. The results indicated that lower concentration of Cd (1 microM) had no obviously influence on the root growth during 24-48 h treatment, but higher concentrations (5-50 microM) inhibited significantly after 48 and 72 h. The mitotic index decreased with increasing of Cd concentration and duration of treatment except for the group exposed to 1 microM Cd. Cd induced c-mitosis, chromosome bridges, chromosome stickiness and lagging chromosomes. The rate of aberrant dividing cells increased with prolonging duration of treatment and increasing of Cd concentration. On nucleolus, some particulates containing the argyrophilic proteins were extruded from the nucleus into the cytoplasm in the cells stressed by Cd and some were scattered in the nucleus. After the treatment with Cd (10 microM Cd, 48 h), the nucleolus did not disaggregate normally and still remain its characteristic structure during metaphase and the particles of similar silver-stained materials were localized on chromosomes. In leaves, Catalase (CAT) activity declined but Peroxidase (POD) activity increased with increasing of the duration of treatment. In roots, CAT activity increased with increasing of the duration of treatment, POD activity increased during early days and then declined. Superoxide dismutase (SOD) activity showed an upward trend with increasing of the duration of treatment after 3 and 6 days, then declined both in leaves and roots (9 days). SOD and POD had highest activities at 50 microM Cd in leaves. CAT activity was lowest at 50 microM Cd. Malondialdehyde (MDA) content increased with the increasing of Cd concentrations and duration of treatment in leaves. In roots, MDA content showed an upward trend with increasing of the duration of treatment at early time and then declined.

Effects of Cadmium Stress on Root Tip Cells and Some Physiological Indexes in Allium Cepa Var. Agrogarum L.

“…In plant cells, cadmium tends to be stored in the apoplast and in vacuoles, which may contribute to Cd tolerance in hyperaccumulator plants and common crops (Boominathan and Doran, 2003;Ma et al, 2005;Liu et al, 2007). Cadmium may cause growth inhibition related to reduction of mitotic activity, induction of chromosome aberrations, toxicity to nucleoli in apical meristems (Liu et al, 2003(Liu et al, /2004Zhang et al, 2009;Qin et al, 2010), damage of macromolecules, mainly proteins and lipids (Skórzyńska-Polit and Krupa, 2006) and DNA (Li et al, 2005), and disturbance of the organization of the microtubular cytoskeleton in interphase and mitotic cells Liu et al, 2009).…”

Cadmium Effects on Mineral Accumulation and Selected Physiological and Biochemical Characters of Salix babylonica L.

“…Generally, these enzymes play a cooperative role in protecting plants. MDA content is generally used as an indicator of oxidative damage to lipid peroxidation [28]. The content of soluble protein in plants exposed to Cd is changed, which plays an important role in avoiding harmful stress.…”

A Pilot Study to Determine the Substrate Threshold for Heavy Metal Toxicity in Groundcover Plants Used in Urban Landscapes

“…The Cd is more toxic than Cu, Pb, and particularly Zn (Kahle, 1993) because of its high solubility in water and its phototoxic effects . The Cd damages membranes and disrupts membrane electron transport, interacts with nucleic acids, and reduces mitotic activity (Zhang et al, 2009). Also, the Cd is the heavy metal most readily absorbed by plants.…”

“…Also, the Cd is the heavy metal most readily absorbed by plants. The Cd toxicity causes leaf rolls, chlorosis, and reduced plant growth (Zhang et al, 2009). …”