(+)-Abscisic Acid Content of Spinach in Relation to Photoperiod and Water Stress

摘要: Levels of (+)-abscisic acid present in the long-day plant spinach (Spinacia oleracea L., cv. Savoy Hybrid 612) grown under different photoperiodic regimes were measured purified extracts by optical rotary dispersion. When plants transferred from short to long days, abscisic content increased 2- 3-fold. This rise level took place during 1st day. Abscisic levels days as well conditions higher at end 8-hour high intensity light period than its beginning.The growth retardant AMO-1618 [2'-isopropyl-4'-(trimethyl-ammonium chloride)-5'-methylphenyl piperidine-1-carboxylate], which strongly reduces gibberellin did not affect content.When water was withheld until wilting symptoms appeared, more 10-fold over that turgid plants. There no evidence sudden due release a water-soluble bound form.Bioassays crude acidic wheat coleoptile section test indicate presence other specific inhibitors besides acid. It is concluded does function an endogenous regulator stem and flower formation spinach.