How does abscisic affect plants

Abscisic acid induces stomatal closure
Abscisic acid can induce the closure of stomates within a few minutes. Water stress in the roots can lead to as much as a 40-fold increase in the abscisic acid levels of the plant. Guard cells use turgor pressure to control the stomatal aperture.

Stimulates the closure of stomata (water stress brings about an increase in ABA synthesis). Inhibits shoot growth but will not have as much affect on roots or may even promote growth of roots. Induces seeds to synthesize storage proteins.