Study of aluminium toxicity in Oryza sativa L. cv. IET- 4094 and its detoxification by organic acid

Experiments were conducted with rice (Oryza sativa L.) cv. IET- 4094 under laboratory condition to study the toxicity effect of Al⁺ on rice seedlings under hydroponic culture. Seven-day-old seedlings were placed on standard rice culture solution in glass beaker. Except control, Al⁺ and organic acids like citric and malic acid were added having concentration of 0.2 mM to 0.3 mM and 0.1 mM to 0.15 mM, respectively. Effect of Al⁺ toxicity on seedling growth were recorded at specific time intervals of 24, 48 and 72 hours and were observed that maximum injury in root occurred in 0.2 mM Al⁺ concentration in 24 hours whereas slow damage was observed in longer durations. Dry matter accumulation of roots significantly reduced in 24 hours than of 48 and 72 hours but compared to control injury in all the concentrations magnified highly. Fortifications of citric and malic acids in the medium nullify the toxicity effect of Al⁺ in roots. Biochemical analysis in relation to proline accumulation and total protein content of the seedlings showed, proline content increases with the increase of time duration as well as concentration of Al⁺, and significant differences were observed compared to control set, where as protein content decreases with the increase of Al⁺ over the durations. From the over all results it indicated that organic acids had detoxification effect of Al⁺ by decreasing the active oxygen species produced due to stress and checking the lipid peroxidation reaction.