Answer»
- The history of the discovery of abscisic acid (ABA) is interesting. In the 1960s, groups of workers were INDEPENDENTLY attempting to isolate and purify a growth-regulating SUBSTANCE.
- One group, led by Addicott and his associates Ohkuma, Smith and Thiessen at the University of California, Davis, obtained from young COTTON bolls two partially purified fractions which accelerated leaf abscission in young cotton seedlings and which they called abscisin I and abscisin II.
- At about the same time, Rothwell and Wain (1964) at Wye College, London University were attempting to identify a substance which accelerated flower drop in lupins.
- Further work, was however, concerned with the isolation and IDENTIFICATION of abscisin II. Following a different approach, Wareing and his co-workers at Aberystwyth, WALES, obtained from sycamore (Acerpseudoplatanus) leaves an acidic extract which was highly active as a growth inhibitor and which was able to induce the formation of resting buds in sycamore seedlings when applied as solution to leaves.
- The active substance was named dormin since it caused bud dormancy. At this stage, further purification of dormin was taken over by Cornforth at Milstead Laboratory of Shell Research Ltd, UK and this resulted in its isolation in crystalline form.
- Thus abscisin II, dormin and lupin flower abscission factor proved to be one and the same compound. At the Sixth International Conference on Plant Growth Substances in Ottawa in 1967, the new name abscisic acid was approved which gives an indication of the compound’s chemical nature.
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