Present address: Plant Science Centre, RIKEN, Yokohama 230-0045, Japan.
Patterns of Dwarf expression and brassinosteroid accumulation in tomato reveal the importance of brassinosteroid synthesis during fruit development
Article first published online: 15 MAR 2005
The Plant Journal
Volume 42, Issue 2, pages 262–269, April 2005
How to Cite
Montoya, T., Nomura, T., Yokota, T., Farrar, K., Harrison, K., Jones, J. G. D., Kaneta, T., Kamiya, Y., Szekeres, M. and Bishop, G. J. (2005), Patterns of Dwarf expression and brassinosteroid accumulation in tomato reveal the importance of brassinosteroid synthesis during fruit development. The Plant Journal, 42: 262–269. doi: 10.1111/j.1365-313X.2005.02376.x
- Issue published online: 15 MAR 2005
- Article first published online: 15 MAR 2005
- Received 24 November 2004; accepted 13 January 2005.
- tomato Dwarf gene expression;
Brassinosteroids (BRs) are essential for many physiological functions in plants, however little is known concerning where and when they are synthesized. This is especially true during flower and fruit production. To address this we have used a promoter-GUS reporter fusion and RT-PCR to determine the relative expression levels of the tomato Dwarf (D) gene that encodes a BR C-6 oxidase. In young seedlings GUS reporter activity was observed mainly in apical and root tissues undergoing expansion. In flowers GUS activity was observed in the pedicel joints and ovaries, whereas in fruits it was strongest during early seed development and was associated with the locular jelly and seeds. RT-PCR analysis showed that tissue-specific expression of Dwarf mRNA was consistent with that of the Dwarf:GUS fusion. In good correlation with the high local Dwarf activity, quantitative measurements of endogenous BRs indicated intense biosynthesis in developing tomato fruits, which were also found to contain high amounts of brassinolide. Grafting experiments showed the lack of BR transport indicating that BR action occurs at the site of synthesis.