The D3 F-box protein is a key component in host strigolactone responses essential for arbuscular mycorrhizal symbiosis

New Phytol. 2012 Dec;196(4):1208-16. doi: 10.1111/j.1469-8137.2012.04339.x. Epub 2012 Oct 1.

Abstract

Arbuscular mycorrhiza (AM) represents an ancient endosymbiosis between plant roots and Glomeromycota fungi. Strigolactones (SLs), plant-derived terpenoid lactones, activate hyphal branching of AM fungi before physical contact. Lack of SL biosynthesis results in lower colonization of AM fungi. The F-box protein, DWARF3 (D3), and the hydrolase family protein DWARF14 (D14) are crucial for SL responses in rice. Here we conducted AM fungal colonization assays with the SL-insensitive d3 and d14 mutants. The d3 mutant exhibited strong defects in AM fungal colonization, whereas the d14 mutant showed higher AM fungal colonization. As D14 has a homologous protein, D14-LIKE, we generated D14-LIKE knockdown lines by RNA interference in the wildtype and d14 background. D14 and D14-LIKE double knockdown lines exhibited similar colonization rates as those of the d14-1 mutant. D3 is crucial for establishing AM symbiosis in rice, whereas D14 and D14-LIKE are not. Our results suggest distinct roles for these SL-related components in AM symbiosis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • F-Box Proteins / genetics
  • F-Box Proteins / metabolism*
  • Gene Expression Regulation, Plant
  • Gene Knockdown Techniques
  • Glomeromycota / physiology*
  • Lactones / metabolism*
  • Mutation
  • Mycorrhizae / physiology*
  • Oryza / physiology*
  • Plant Proteins / genetics
  • Plant Proteins / metabolism*
  • Plants, Genetically Modified
  • RNA Interference
  • Symbiosis / physiology*
  • Terpenes / metabolism*

Substances

  • F-Box Proteins
  • Lactones
  • Plant Proteins
  • Terpenes