M. Deagazio et al., INHIBITION OF MAIZE PRIMARY ROOT ELONGATION BY SPERMIDINE - EFFECT ONCELL-SHAPE AND MITOTIC INDEX, Journal of plant growth regulation, 14(2), 1995, pp. 85-89
Spermidine applied for 18 h to intact maize seedlings through their ro
ots reduces root growth 70%, and the effect is reversible. Histologica
l observations of longitudinal sections of 0.4-cm root apical segments
from 2-day-old maize seedlings grown for 18 h in 0.5 mM CaSO4 solutio
n with or without 1 mM spermidine contribute to the explanation of spe
rmidine-dependent slow root growth, In the meristematic zone a strong
reduction of the mitotic index and in the elongation zone an inhibitio
n of cell elongation occur simultaneously. Cell shape analysis along t
he growth axis of the maize root apex expressed in terms of form facto
r (FCircle) values substantiates the dual effect of spermidine on mito
tic activity and cell elongation.