title: Phytochrome-mediated delay of plastid senescence in mustard cotyledons: changes in pigment contents and ultrastructure.
abstract: Changes in pigment contents and ultrastructure have followed in cotyledons of mustard (Sinapis alba L.) seedlings during dark-mediated senescence. The seedlings were kept in white light for 7 d, treated with 5 min long wavelength far-red light and then kept in darkness up to 14 d after sowing. Under these conditions the chloroplasts remain stable for 2 d before a sequential plastidal disintegration commences. The data indicate a selective breakdown of the light-harvesting chlorophyll a/b protein. Phytochrome retards the differential loss of chlorophyll a, b and carotenoids and preserves the fine structure of chloroplasts.
authors.affiliation: Biologisches Institut II der Universität, Schänzlestrasse 1, D-7800, Freiburg, Federal Republic of Germany.
authors.forename: U C
authors.initials: UC
authors.lastname: Biswal
authors.forename: R
authors.initials: R
authors.lastname: Bergfeld
authors.forename: H
authors.initials: H
authors.lastname: Kasemir