ABSTRACT
This chapter attempts to integrate the current knowledge on the physiology and regulation of ethylene biosynthesis, focuses on factors studied in the context of the primary biosynthetic pathway. Another aspect of polyamine-mediated regulation of ethylene biosynthesis is the effect of spermine on the development of 1-aminocyclopropane-1-carboxylic acid (ACC) synthase activity. Abscisic acid (ABA) participates in the regulation of embryogenesis, seed maturation, environmental stresses, and senescence. Considerable information is available on the physiology and regulation of ethylene biosynthesis. An early indication that membrane integrity may be an important factor regulating ethylene biosynthesis was the finding that in apple tissue ethylene production was sensitive to solute concentration of the medium. Brassinosteroids, originally isolated from Brassica pollen, are growth stimulators that seem to act synergistically with auxin and stimulate ethylene biosynthesis in mung bean segments. The induction of ethylene biosynthesis by specific oligossaccharides of either plant or fungal origin promises to be a relevant model of pathogenesis, in addition to fruit ripening.
