Figure 7. Foliage abscisic acid (ABA) levels as branches of the
angiosperm species Umbellularia californica that were rehydrated
overnight were subsequently dehydrated on the laboratory bench for 12 h.
Bench dehydration started at time = 0. Branches were taken from either
unstressed plants (white), plants that were exposed to a soil drought
for 10 d after peak ABA levels were measured (grey) (data from Figure
4), or plants exposed to soil drought for 10 d after peak ABA levels
were measured then rewatered and maintained in saturated soil for 3 d
(black squares). Data are taken from leaves collected from 5 branches.
Generalized additive model (GAM) curves and standard errors are
represented by black solid and dashed lines for ABA levels in branches
harvested from U. californica plants exposed to drought for 10 d
after peak ABA and grey lines for ABA levels in branches harvested from
unstressed U. californica plants, a significant linear regression
is shown for the data collected from a rehydrated plant.