Cytokinin-induced parthenocarpic fruit development in tomato is partly dependent on enhanced gibberellin and auxin biosynthesis

PLoS One. 2013 Jul 29;8(7):e70080. doi: 10.1371/journal.pone.0070080. Print 2013.

Abstract

Fruit set of plants largely depends on the biosynthesis and crosstalk of phytohormones. To date the role of cytokinins (CKs) in the fruit development is less understood. Here, we showed that parthenocarpic fruit could be induced by 1-(2-chloro-4-pyridyl)-3-phenylurea (CPPU, an active CK) in tomato (Solanumlycopersicum cv. Micro-Tom). The fresh weight of CPPU-induced parthenocarpic fruits was comparable with that induced by GA3. Importantly, CPPU-induced parthenocarpy was found to be compromised by simultaneous application of paclobutrazol (a GA biosynthesis inhibitor), and this effect could be restored by exogenous GA3. Like pollination, CPPU-induced fruit showed enhanced accumulation of GA1+3 and indole-3-acetic (IAA), which were accompanied by elevated expression of GA biosynthesis genes like SlGPS, SlGA20ox1, SlGA20ox2 and SlGA3ox1, and IAA biosynthesis gene ToFZY. Elevated GAs level in CPPU-induced fruits was also associated with down-regulation of GA inactivation genes, namely SlGA2ox1,2,3,4,5 in comparison with untreated control. These results suggested that CKs may induce parthenocarpy in tomato partially through modulation of GA and IAA metabolisms.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cytokinins / pharmacology*
  • Fruit / drug effects*
  • Fruit / growth & development
  • Fruit / metabolism*
  • Gibberellins / metabolism*
  • Indoleacetic Acids / metabolism*
  • Polyethylene Glycols / pharmacology
  • Polyurethanes / pharmacology
  • Solanum lycopersicum / drug effects*
  • Solanum lycopersicum / growth & development
  • Solanum lycopersicum / metabolism*
  • Xanthones / pharmacology

Substances

  • Cytokinins
  • GA3 compound
  • Gibberellins
  • Indoleacetic Acids
  • Polyurethanes
  • Xanthones
  • co(polyether)polyurethane
  • Polyethylene Glycols
  • indoleacetic acid

Grants and funding

This work was supported by the National Basic Research Program of China (2009CB119000), the Program for New Century Excellent Talents in University, and the Fok Ying-Tong Education Foundation (132024). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.