Effect of strontium on the growth, ion balance, and suberin induction in Solanum lycopersicum

Abstract

Non-isotopic strontium (Sr) is a non-essential element found in the environment but its effect on plants is unknown. Sr amount may reach even several thousands of ppm at near roads with heavy traffic. The effect of high Sr concentration on vegetative plants has not been investigated. Here, the effect of Sr on the growth of Solanum lycopersicum was studied. The fresh weights of the shoots and roots were reduced by addition of Sr in a dose-dependent manner, suggesting that a high Sr concentration is toxic to the tomato plant. The Sr concentration in the shoots and roots increased in a dose-dependent manner. The Sr concentration in the shoots was 2 to 4 fold higher than that in the roots. Shoots treated with 10 mM Sr had a higher accumulation of Mg, and Ca ions than those in the control shoots. Roots treated with 10 mM Sr only had a higher Ca accumulation than that in the control. The tomato roots were stained by Fluorol Yellow 088 to observe the formation of suberin. In the mature zone of roots, the fluorescence of suberin was increased by 10 mM Sr treatment, indicating that suberin induction caused higher Ca accumulation.