Abscisin II, an Abscission-Accelerating Substance from Young Cotton Fruit

Abstract

Crystalline abscisin II, with a tentative molecular formula of C(15)H(20)O(4), has been isolated from young cotton fruit. It accelerates abscission when applied in amounts as low as 0.01 microg per abscission zone. It inhibits indoleacetic acid-induced straight growth of Avena coleoptiles but has no gibberellin activity on dwarf maize.

Identification of Plant Hormones from Cotton Ovules

“…Many research workers have attempted to identify and measure hormone levels in cotton plants by using various bioassays (1,6,7,9,24,25,28). Because plant hormones are present in microgram quantities, the usefulness of bioassays has been limited because of interference of excessive quantities of impurities in extracts containing the hormones (2,14).…”

“…A single extract contained abscisic acid, indoleacetic acid, and gibberellins A1, A3, A4. A7, A9, and A13 in the first fraction; ethyl indole-3-acetate and indole-3-aldehyde in the second fraction; and the cytokinins 6-(3-methyl-4-hydroxybutylamino)purine (dihydrozeatin), 6-(4-hydroxy-3-methyl-2-trans-butenylamino) purine (zeatin), 6-(3-methyl-2-butenylamino)purine (2iP), 6-(3-methyl-2-butenylamino) .9 -A -D -ribofuranosylpurine (2iPA), and 6-(4-hydroxy-3-methyl-2-trans-butenylamino) -9-/3-D-ribofuranosylpurine (zeatin riboside) in the third fraction.Many research workers have attempted to identify and measure hormone levels in cotton plants by using various bioassays (1,6,7,9,24,25,28). Because plant hormones are present in microgram quantities, the usefulness of bioassays has been limited because of interference of excessive quantities of impurities in extracts containing the hormones (2,14).…”

Ruta de transducción de señal del ácido abscísico: Regulación por HAB1 y dianas de interacción. La inactivación combinada de PP2Cs como herramienta biotecnológica para incrementar la tolerancia a sequía en plantas

“…El ABA se caracterizó por laboratorios que estaban interesados en el aislamiento de reguladores de crecimiento endógenos. Concretamente, el grupo de Addicott buscaba un compuesto del algodón que promoviese la abscisión de la hoja a partir de cotiledones en proceso de abscisión [177]. El compuesto obtenido, denominado abscisina II, tenía un efecto inhibidor del crecimiento del coleóptilo de avena aunque el efecto del ABA como promotor de la abscisión era un efecto indirecto producido por la inducción de la biosíntesis de etileno [28].…”

Structural insights into ABA perception and signalling: structure of ABA receptor PYR1

“…Ohkuma et al wanted to isolate compounds that were responsible for promoting leaf abscission in cotton. The compound isolated was named Abscissin II (Ohkuma et al 1963). Cornforth et al (1965) also looked for compounds that were promoting bud dormancy, thinking that these compounds might likely be general inhibitors.…”

“…The compound that was eventually named as abscisic acid (ABA) was first discovered in the 1960s by several groups when trying to isolate endogenous plant regulators (Ohkuma et al 1963, Cornforth et al 1965, Cracker et al 1969). Ohkuma et al wanted to isolate compounds that were responsible for promoting leaf abscission in cotton.…”