Identification and characterization of tomato gibberellin 2-oxidases (GA2oxs) and effects of fruit-specific SlGA2ox1 overexpression on fruit and seed growth and development

The role of certain hormones in tomato fruit development has been verified by manipulating the enzymes that catalyze their breakdown. Gibberellins are a key group of plant hormones involved in the growth and development of all plant tissues, including fruits and seeds. The concentration of gibberellins, and thus their activity, is influenced by both their synthesis and breakdown, the latter catalyzed by enzymes known as 'GA2-oxidases'. An international team led by Han Wu and Yi Li of Nanjing Agricultural University, China, developed a novel method to study gibberellin action in tomatoes, by genetically increasing production of GA2-oxidases. They used fruit-specific control genes to investigate gibberellin action in fruits without impacting on other tissues. The team discovered that gibberellins play an important role in regulating fruit size and weight as well as seed development and germination.