Physiological resposes of Ocimum basilicum Var. Purpurascens to aluminium toxicity

The aim of the present study is to evaluate the physiological effects of Al3+ application on the O. basilicum var. purpurascens (purpleruffles) seedlings, which were grown in a climate chamber as hydroponically. For experiment, O. basilicum var. purpurascens seeds were used. The seeds sterilized with 5% sodium hypochloride solution for 15 min, washed with distiled water three times and then were germinated in perlite forunder 24±1 °C. Purple ruffles seedlings were then transferred to 2 L plastic vessels containing aerated nutrient solution. After seedlings were acclimatized in nutrient solution, they were supplied with 0, 5, 25 and 50 mg/L Al3+. The seedlings were harvested after 12 days than contents of chlorophylls (a and b), carotenoid, anthocyanin, total protein, total phenolics, total solublecarbohyrdates, non-protein –SH groups, H2O2 and malondialdehide (MDA) were investigated. Roost, leaves and stems were separated and dried at 80 °C in order to determine dry weight and Al3+ content. Because of Al toxicity, growth and development of the seedlings were reduced. A dose-dependent reduction was found in chl-a, chl-b and carotenoid contents of the seedling leaves. However, anthocyanin content did not significantly change. In addition to this, protein content was decreased by Al3+. Total soluble cahrbohyrate contents were increased by Al3+. The maximum increase was determined for root in 5 mg/L Al3+ as 39,43%, forstem in 50 mg/L Al3+ as 94,98%, and for leaf in 50 mg/L Al3+ as 14,27%. Besides, a dose-dependent increas was generally determined on the contents of MDA, H2O2, total phenolics and non-protein –SH groups. These results suggest a possible Al-induced oxidative stress in purple ruffles seedlings.