title: Pigment content and leaf plastid ultrastructure in the tomato mutant lutescent-2.
abstract: The non-lethal tomato mutant «lutescent-2» shows an early yellowing of normal developed leaves. Its ripe fruits display a yellow colouring, red pigment synthesis being delayed by up to two weeks. Typical pigment synthesis, related to leaf maturation, does not occur in mutant leaves. Both the concentration of chl a and chl b start to decrease very quickly at the end of leaf expansion. Early yellowing of «1-2» leaves appears to be related to the reduced car(470) content, which leads to chlorophyll photooxidation. Structural evidence of a deficiency in car(470) content in young «1- 2» plastids is given by a reduction of stroma thylakoids as well as by a limited grana stacking. The altered balance between the two pigment classes determined an active, even if incomplete, conversion of chloroplasts to chromoplast-like organelles.
authors.affiliation: Istituto e Orto Botanico, Università di Modena, Viale Caduti in Guerra, 127, 41100 Modena, Italy.
authors.forename: R B
authors.initials: RB
authors.lastname: Fornasiero
authors.forename: P M
authors.initials: PM
authors.lastname: Bonatti