Abstract
The fruit vacuole is a large organelle accumulating sugar or organic acid in high concentration. To clarify the role of vacuolar H+-pump in fruit growth and solute accumulation, we generated antisense-transgenic tomatoes of the V-ATPase A subunit, which is under the control of a 2A11 fruit-specific promoter. Miniature-dwarf tomato (Micro-Tom) was used to transformation mediated by A. tumefaciens.
A subunit mRNA level in fruit decreased in antisense-transgenic lines, while that in leaves showed no difference compared with the GUS control line and non-transformant. This suggests that suppression is limited to fruit. The antisense-transgenic plants had smaller fruits and had few seed, although the plant growth was normal. These results considered to correlates with A subunit mRNA level. Sucrose concentration in fruits increased, although glucose and fructose concentration did not change. These results show the V-ATPase expression affect not only in fruit growth but also in seed formation and sugar composition.
