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Abstract
Aim:
To investigate the potential of sodium arsenite to induce physiological as
well as oxidative stress at its low level exposure in tolerant and sensitive
indica rice cultivars.
Methodology: Rice seeds were surface sterilized using 0.1% HgCl2
for 15 min, followed by washing with distilled water. Twelve days after
germination, the seedlings in one tray was kept aside as control and other trays
were exposed to 50, 100, 150 and 200 μM of sodium arsenite. After treatment
for 24 and 48hr, leaves were harvested and washed with distilled water to
estimate the level of lipid peroxidation as well as physiological stress
parameters.
Results: The oxidative
damage increased with corresponding increase in the sodium arsenite
concentration in both the succeptible IR-64 and tolerant Nonabokra cultivars,
the effect being more prononced in IR-64 than Nonabokra. The status of lipid
peroxidation was assessed through quantification of its secondary product
malondialdehyde by TBARS assay (P≤0.05). Significant increase in lipid
peroxidation levels were observed in all the arsenic exposed groups of rice
plants.
Interpretation: The detrimental
effect of arsenic was reflected as more chlorophyll loss, decrease in water
content and significant reduction in the length of root as well as shoot of
rice plants. Besides, significant elevated levels of LPO indicated drastic
cellular damage in all the arsenic exposed groups of rice plants.
Key words: Chlorophyll loss,
Indica rice, Lipid peroxidation, Sodium arsenite, Water content
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