Lead stress-induced changes of antioxidant

Catalase activity

The Catalase activity was assayed by the method of Chance and Maehly (1955).

Phenylalanine ammonialyase activity

Phenylalanine ammonialyase activity was done as described by Dickerson et al .,

(1984).

Ascorbic acid oxidase activity

Determination of ascorbic acid oxidase was done according to method of

Oberbacher and Vines (1963).

Total starch content

The total starch content was estimated by the anthrone–sulphuric acid method

according to Hodge and Hofreiter (1962).

AAS analysis

The properties of soil sample were measured according to Liu (2000). Total

metal concentration of Soil and plant metal concentration (digested by 5:1

with concentrated HNO ₃ and HClO ₄ were determined by atomic absorption

spectrophotometry.

Statistical analysis

Statistical analysis was performed using spss version 11.5. All data were analyzed

using one-way analysis of variance (ANOVA). Different letters in graphs or tables

indicate significant differences at P<0.05. All values were presented as means ±

standard error of the mean (SE), with a minimum of three replicates.

Results and Discussion

Lead uptake

In the present study Pb accumulation by different plants varied significantly

(Anova, P < 0.05). Among the plants taken Calotropis procera showed highest

amount of accumulation (90.5 mg/kg). This was about 5 times higher than in

Eichornia fasculata (10.8 mg/kg) followed by Bromus tectorum (77.1 mg/

kg), Ipomea purpurea (72.1 mg/kg), Parthenium histocarpus (33.7 mg/kg) and

Anisomilius molabarica (29.7 mg/kg).

The Organic carbon content of the soils was determined as moderate which

indicated that metals were less likely to be bound to organic matter to form metal-

chelate complexes. This will make metals into available form for easy accessibility

Int. J. Bioinformatics and Biological Sci.: v.2 n.1&2, p. 13-22. March & June 2014

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