The wide range of pleiotropic effects on plant architecture mediated by a single ‘flowering’ gene, suggests that it is used to co-ordinate many developmental events, and thus may underlie some of the widespread variation in the Solanaceae shoot architecture.
In agreement with the major effect of FASCICULATE imposed on sympodial development, the gene transcripts were localized to the centre of sympodial shoots but could not be detected in the primary shoot. Ectopic expression of FASCICULATE complemented the Arabidopsis tfl1 mutant plants and as expected, stimulated late flowering. Sequence comparison between wild-type and fa plants revealed a duplication of the second exon in the mutants' orthologue of SP, leading to the formation of a premature stop codon. fa was mapped to pepper chromosome 6, in a region corresponding to the tomato SELF-PRUNING ( SP) locus, the homologue of TFL1 of Arabidopsis. Developmental analysis of these clusters revealed shorter sympodial units and, often, precocious termination prior to sympodial leaf formation. fasciculate plants are characterized by the formation of floral clusters separated by short internodes and miniature leaves and by early flowering. The basic sympodial unit in wild-type pepper comprises two leaves and a single terminal flower. To study shoot architecture in pepper, sympodial development is described in wild type and in the classical recessive fasciculate ( fa) mutation. Wild peppers ( Capsicum spp.) are either annual or perennial in their native habitat and their shoot architecture is dictated by their sympodial growth habit.
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