Abstract
Cd in soils, which can accumulate in agricultural product, threatens food safety. Phytoremediation is the attempt to clean up soils contaminated with Cd or other heavy metals using plants. To facilitate the attempt, we should know what happens in plant cells when they encounter heavy metals. We tried here to isolate Arabidopsis mutants that show altered responses to Cd, aiming to know what determines plant responses to Cd. In the screening, Cd-gradient agar plates were prepared, in which gradation of Cd concentration was formed. EMS-treated M2 seeds were planted onto the plates vertically set in growth chambers, so that roots elongate against the Cd gradient. Normal plants cease root elongation, as root tips proceed to Cd-rich regions. We successfully obtained some mutant lines: one elongated primary roots longer than WT against the Cd gradient, other stopped elongation of primary roots earlier and produced many lateral roots at Cd-free regions.
