title: Inhibition of phenolic acid metabolism results in precocious cell death and altered cell morphology in leaves of transgenic tobacco plants
abstract: Several complex phenotypic changes are induced when the transcription factor AmMYB308 is overexpressed in transgenic tobacco plants. We have previously shown that the primary effect of this transcription factor is to inhibit phenolic acid metabolism. In the plants that we produced, two morphological features were prominent: abnormal leaf palisade development and induction of premature cell death in mature leaves. Evidence from the analysis of these transgenic plants suggests that both changes resulted from the lack of phenolic intermediates. These results emphasize the importance of phenolic secondary metabolites in the normal growth and development of tobacco. We suggest that phenolic acid derivatives are important signaling molecules in the final stages of leaf palisade formation and that phenolic acid derivatives also play a prominent role in tissue senescence.
authors.affiliation: John Innes Centre, Norwich Research Park, Colney Lane, Norwich NR4 7UH, United Kingdom.
authors.initials: L
authors.lastname: Tamagnone
authors.initials: A
authors.lastname: Merida
authors.initials: N
authors.lastname: Stacey
authors.initials: K
authors.lastname: Plaskitt
authors.initials: A
authors.lastname: Parr
authors.initials: CF
authors.lastname: Chang
authors.initials: D
authors.lastname: Lynn
authors.initials: JM
authors.lastname: Dow
authors.initials: K
authors.lastname: Roberts
authors.initials: C
authors.lastname: Martin