Finally, the polyamines studied here are ubiquitous in plant cells at
c onc en tr a ti on s va ry in g fr om mi c ro mo la r to mo re t ha n mi ll im ol a r
depending greatly on environmental conditions, in particular stress [35].
It is thus plausible to envisage a way of fighting viroids by modulating
the polyamine biosynthesis or by adding exogenous polyamine. A
decrease in the activity of ribozymes could affect the equilibrium
between linear, circular, and polymeric genomes in infected cells and
thus allow nucleases to eliminate the viroid before it completes its
replication cycle.