A more abundant production of lateral roots in Vicia faba seedlings wa
s observed after treatment with ascorbic acid, an effect which was pri
marily due to enhanced pericycle cells activity. The histochemical loc
alization, as revealed by the reduction of silver nitrate into metalli
c silver, demonstrated that a wide stain intensity is detectable in th
e pericycle nuclei in a zone ranging between 2000 and 2500 mum from th
e root tip. In this context, the high ascorbic acid content seems to b
e related to the onset of the metabolic activation for the production
of lateral roots primordia. On the basis of these observations, it may
be speculated that exogenous ascorbic acid, which is known to be invo
lved in nucleic acids metabolism, might be both accumulated and utiliz
ed by the nuclei of pericycle cells.