title: Procera is a putative DELLA mutant in tomato (Solanum lycopersicum): effects on the seed and vegetative plant.
abstract: The procera (pro) mutant of tomato exhibits a well-characterized constitutive gibberellic acid (GA) response phenotype. The tomato DELLA gene LeGAI in the pro mutant background contains a point mutation that results in an amino acid change in the conserved VHVID putative DNA-binding domain in LeGAI to VHEID. This same point mutation is in four different genetic backgrounds exhibiting the pro phenotype, suggesting that this mutation co-segregates with the pro phenotype. Complementation of the mutant with a constitutively expressed wild-type LeGAI gene sequence was not conclusive due to the infertility of transgenic plants. The pro mutation alters tomato branching architecture through differential suppression of axillary bud development, indicating a role for DELLA proteins in the regulation of plant structure. Isolated gib-1 pro double mutant embryo axes, which are unable to synthesize GA, germinate faster than their wild-type counterparts, and exert greater embryo growth potential. The pro mutation is therefore regulating GA responses within the tomato embryo. Transient expression of a LeGAI-GFP (green fluorescent protein) fusion protein in onion epidermis results in its location to the nucleus, and this protein is rapidly degraded by the proteasome in the presence of GA.
authors.affiliation: Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada, N1G 2W1. gbassel@csb.utoronto.ca
authors.forename: George W
authors.initials: GW
authors.lastname: Bassel
authors.forename: Robert T
authors.initials: RT
authors.lastname: Mullen
authors.forename: J Derek
authors.initials: JD
authors.lastname: Bewley
mesh_terms: D002467:Cell Nucleus / Q000378:metabolism; D015870:Gene Expression; D018525:Germination / Q000235:genetics*; D005875:Gibberellins / Q000378:metabolism*; D049452:Green Fluorescent Proteins / Q000378:metabolism; D018551:Solanum lycopersicum / Q000235:genetics* / Q000254:growth & development; D009154:Mutation; D010641:Phenotype; D010940:Plant Proteins / Q000235:genetics*; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D012639:Seeds / Q000254:growth & development / Q000378:metabolism*
chemical_list: D005875:Gibberellins; D010940:Plant Proteins; D049452:Green Fluorescent Proteins; C007842:gibberellic acid; D046988:Proteasome Endopeptidase Complex