Ionomic responses of hydroponic-grown basil (Ocimum basilicum L.) to cadmium long-time exposure

The ionomic response of basil leaves, stems, and roots to Cd2+ was evaluated in seedlings grown in a hydroponic system for 15 days. Ions were quantified by the inductively coupled plasma-mass spectrometry (ICP-MS). Cd accumulated mainly in roots, while Be, Li, Ca, Mg, and Sr in leaves, and K and Mn in stems. Compared to the control group, basil seedlings treated with Cd2+ accumulated higher Ca, Cu, Mn, Sr, and Zn contents in roots, even when exposed at low levels. Pearson positive correlations between Cd and essential and nonessential elements were mostly observed in leaves and roots (P < 0.05). On the other hand, negative correlations were observed mainly in stems with all elements except Ba, Li, Sr, and Zn. Principal component analysis showed an ionomic discrimination between leaves, stems, and roots, with Cd strongly correlated to Zn, Cu, and Sr.