Abscisic acid

Description

Abscisic acid is a hormone that can cause plants to lose their leaves, a process known as abscission. In the 1960s, researchers determined its structure and showed that it is found in many plants. Subsequent research showed that it is involved with abscission in only a few plants but that it is an important signalling molecule for responses to environmental stresses.
It was once thought that applying abscisic acid to crop plants would help them resist drought. But the hormone is expensive to produce, has a short half-life, and is photodegradable. Recently, S. R. Cutler and colleagues at the University of California, Riverside, discovered that the sulfonamide quinabactin binds and activates abscisic acid receptors. This compound may eventually be used to help plants retain water and resist drought, but much developmental and regulatory work needs to be done.

Chemical properties

white to light yellow crystalline powder

The Uses of Abscisic acid

Abscisic acid (ABA) is an isoprenoid plant hormone (phytohormone) synthesized in all parts of plants and involved in many plant developmental processes. ABA is involved in establishing dormancy and regulation of stress responses. ABA inhibits fruit ripening, seed germination, photosynthesis and kinetin biosynthesis.

The Uses of Abscisic acid

abscission-accelerant; kinetin neucleotide synthesis inhibitor

Definition

ChEBI: 2-cis-abscisic acid is a member of the class of abscisic acids in which the double bond betweeen positions 2 and 3 has cis- (natural) geometry. It has a role as an abscisic acid receptor agonist. It is a conjugate acid of a 2-cis-abscisate.

Agricultural Uses

The name abscisic acid (ABA), a weak organic acid, is derived from the ability of a substance to promote abscission. Abscission is the natural detachment of leaves, branches, flowers, etc. from plants. Abscisic acid is a naturally occurring plant growth inhibitor, and is one of five major plant hormones. It carries out a number of important functions in the growth and development of plants. It is a key factor controlling stomatal movements, leaf senescence and bud and seed dormancy. Abscisic acid (ABA) is present in leaves, fruits and seeds, and is distributed throughout the plant body. The synthesis of ABA takes place mainly in chloroplasts. The rate of synthesis of ABA increases when the plant is under stress. Chemically, abscisic acid is a member of the terpenoid family.

Metabolic pathway

Plant growth regulators: promotion of maturation of the somatic embryo of white spruce Somatic embryo suspension cultures of white spruce containing (?+)-abscisic acid (ABA) metabolize (+?)- ABA almost completely to yield quantitatively phaseic acid with slight further transformation into dihydrophaseic acid within 7 days. (-)-ABA remains essentially unchanged under the same culture conditions, and when the cells are supplied with racemic (±)-ABA, only the (+?) enantiomer is metabolized.