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Phytochrome-controlled Nyctinasty in Albizzia julibrissin

1972; Oxford University Press; Volume: 50; Issue: 4 Linguagem: Inglês

10.1104/pp.50.4.523

1532-2548

Ruth L. Satter, Philip B. Applewhite, Arthur W. Galston,

Botanical Research and Applications

We have reported that phytochrome-controlled nyctinastic leaflet movement in Albizzia julibrissin is accompanied and probably caused by K flux in pulvinule motor cells (16, 18); however, the metabolic events linking photon absorption by phytochrome to K flux are still unknown.Jaffe (11) reported that R' irradiation increased and subsequent FR decreased the titer of ACh in etiolated mung bean root tips, and proposed a general theory of phytochrome action based on ACh as a regulator of bioelectric potential and ion flow in plants.He suggested that changes in the ACh titer, following soon after photon absorption by phytochrome, couple it to both rapid be- havioral changes and photomorphogenesis (12).Hartmann (10) has also found ACh levels to be mediated by phytochrome in moss callus.ACh is photomimetic in inducing sporulation in the fungus Trichoderma (8) but not in promoting anthocyanin synthesis in mustard seedlings (13).These reports prompted us to investigate a possible role for ACh, not only in phytochrome-controlled nyctinastic leaflet movement in Albizzia (16, 18) but also in rhythmic movements, since they are also accompanied by K flux (16, 17), and rhyth- mic changes in ACh have been reported in animals (9).In addi- tion, we assayed ACh in several other plants with moving leaves or with dramatic photomorphogenic behavior.