Abscisic acid (ABA) fully suppressed the development of the
hypersensitive necrosis of potato tuber slices to crude elicitor from
Phytophthora infestans and arachidonic acid (AA) if supplied before or
up to 6 to 8 h after elicitor treatments. Later application of ABA
only reduced the necrotic response. Added to highly purified plasma
membrane preparation from tuber tissue, ABA eliminated the AA-induced
inhibition of the plasma membrane-bound (K+ + Na+ + Mg2+)ATPase. It is
suggested that ABA counteracts AA in the membrane.