  The jasmonate (JA) signaling pathway in plants is activated as defense
response to a number of stresses like attacks by pests or pathogens and
wounding by animals. Some recent experiments provide significant new knowledge
on the molecular detail and connectivity of the pathway. The pathway has two
major components in the form of feedback loops, one negative and the other
positive. We construct a minimal mathematical model, incorporating the feedback
loops, to study the dynamics of the JA signaling pathway. The model exhibits
transient gene expression activity in the form of JA pulses in agreement with
experimental observations. The dependence of the pulse amplitude, duration and
peak time on the key parameters of the model is determined computationally. The
deterministic and stochastic aspects of the pathway dynamics are investigated
using both the full mathematical model as well as a reduced version of it. We
also compare the mechanism of pulse formation with the known mechanisms of
pulse generation in some bacterial and viral systems.
