Figure 8. Pressure volume curves for leaves of the angiospermUmbellularia californica (A) and small branches of the coniferCallitris rhomboidea (B) (n=5) in never-before stressed plants
(black) and plants that had experienced long-term drought and at least
10 d at a leaf water potential (Ψl) more negative than
when peak foliage abscisic acid (ABA) level occurred (open circles). Red
dashed vertical lines represent the Ψl at peak foliage
ABA level. Black vertical and dashed lines represent mean
Ψl at turgor loss point (Ψtlp) and
standard error for tissue collected from plants under long-term drought.
Grey solid and dashed vertical lines represent mean Ψtlpand standard error for leaves of never-before stressed plants.