Comparison of effect of salt stress on the cell death in seminal root and lateral root of rye seedlings by the modified TUNEL method

Cell death in the lateral root tip of rye seedlings under salt stress conditions was analyzed quantitatively by the modified terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) method and the frequency of cell death was compared in the seminal root tip. There were no significant differences in total root length and the number of root tips among control, 10 mM and 100 mM NaCl treatments, although the root elongation and initiation was inhibited in the 250 mM NaCl treatment. The frequency of cell death was increased in 100 mM and 250 mM NaCl treatments compared with the control, significantly. There was no significant difference in the frequency of cell death between seminal root and lateral root in all stress treatments. Moreover, technical advantage of the modified TUNEL method was discussed by comparing with the classical TUNEL method.