Constitutive expression of the sunflower and chrysanthemum genes of the AP1/FUL group changes flowering timing in transgenic tobacco plants

Abstract

Flowering is the most important and difficult moment in the life cycle of higher seed plants. Intense analysis of the genetic and molecular mechanisms underlying the transition from vegetative to generative growth of a model plant Arabidopsis thaliana made it possible to determine the genes repressing the floral transition (genes supporting the vegetative state of the meristem) and the genes promoting floral transition [1]. The genes APETALA1 (AP1) and FRUITFULL (FUL) were found to play the key role in determining the flower meristem identity; they control thereby a transition from vegetative to reproductive growth [2, 3]. In addition, the AP1 gene is involved in sepal and petal formation [2], whereas the FUL gene expression is required for proper morphogenesis of A. thaliana fruits [4]. Numerous genes homologous to AP1/FUL have been identified in various plant species [5]. The constitutive expression of the AP1 and FUL genes and of homologous genes results in changes in the flowering time and morphology of the transgenic plants [6–13].