An enzyme to degrade lettuce endosperm cell walls. Appearance of a mannanase following phytochrome- and gibberellin-induced germination

摘要: Lettuce seeds (Lactuca sativa L. cv. Grand Rapids) stimulated to germinate by gibberellin and red light produce large amounts of endo-β-mannanase. This enzyme increases markedly following radicle emergence is capable degrading mannose-containing polysaccharides, which are the major components endosperm cell wall. Non-germinated contain little under conditions where gibberellin- or light-stimulated germination prevented (eg. abscisic acid prolonged far light) levels remain low. Cycloheximide inhibits increase in when supplied germinating seeds, but once produced stable vivo presence this inhibitor for at least 24h. The majority extractable mannanase activity located we propose that function mobilise wall polysaccharides as a nutrient source growing embryo.