Metabolic changes in fruits of the tomato dx mutant

Phytochemistry. 2006 Oct;67(20):2232-8. doi: 10.1016/j.phytochem.2006.07.008. Epub 2006 Aug 22.

Abstract

The tomato DWARF cytochrome P450 protein catalyzes the C-6 oxidation of 6-deoxo-castasterone to castasterone. The d(x) mutant does not produce a functional DWARF enzyme, and d(x) shoots display severe symptoms of brassinosteroid-deficiency. However, fruits express the CYP85A3 protein which compensates for the deficiency of the DWARF protein and produce bioactive brassinosteroids. Here, we report on the metabolic characterization of d(x) fruits. Fruit size, fresh weight, and pigment content were not altered. However, d(x) fruits showed reduced dry mass content. Levels of starch and various sugars were reduced, amino acid levels were elevated. BR application to d(x) leaves partially normalized dry mass content, sugar and amino acid levels in d(x) fruits. The data demonstrate that brassinosteroid in shoots is required for fruit development in tomato.

MeSH terms

  • Amino Acids / metabolism
  • Carbohydrate Metabolism
  • Flowers / genetics
  • Flowers / growth & development
  • Flowers / metabolism
  • Fruit / genetics
  • Fruit / growth & development
  • Fruit / metabolism*
  • Plant Growth Regulators / pharmacology*
  • Plant Proteins / genetics*
  • Plant Shoots / genetics
  • Plant Shoots / metabolism
  • Solanum lycopersicum / anatomy & histology
  • Solanum lycopersicum / genetics
  • Solanum lycopersicum / metabolism*
  • Starch / metabolism

Substances

  • Amino Acids
  • Plant Growth Regulators
  • Plant Proteins
  • Starch