Differential activation of H+-ATPase genes by an arbuscular mycorrhizal fungus in root cells of transgenic tobacco

Planta. 2000 Oct;211(5):609-13. doi: 10.1007/s004250000323.

Abstract

In arbuscular mycorrhizas, H+-ATPase is active in the plant membrane around arbuscules but absent from plant mutants defective in arbuscule development (Gianinazzi-Pearson et al. 1995, Can J Bot 73: S526-S532). The proton-pumping H+-ATPase is encoded by a family of genes in plants. Immunocytochemical studies and promoter-gusA fusion assays were performed in transgenic tobacco (Nicotiana tabacum L.) to determine whether the periarbuscular enzyme activity results from de-novo activation of plant genes by an arbuscular mycorrhizal fungus. The H+-ATPase protein was localized in the plant membrane around arbuscule hyphae. The enzyme was absent from non-colonized cortical cells. Regulation of seven H+-ATPase genes (pma) was compared in non-mycorrhizal and mycorrhizal roots by histochemical detection of beta-glucuronidase (GUS) activity. Two genes (pma2, pma4) were induced in arbuscule-containing cells of mycorrhizal roots but not in non-mycorrhizal cortical tissues or senescent mycorrhiza. It is concluded that de-novo H+-ATPase activity in the periarbuscular membrane results from selective induction of two H+-ATPase genes, which can have diverse roles in plant-fungal interactions at the symbiotic interface.

MeSH terms

  • Cytoplasmic Granules / enzymology
  • Cytoplasmic Granules / ultrastructure
  • Fungi / physiology*
  • Gene Expression Regulation, Enzymologic
  • Gene Expression Regulation, Plant*
  • Plant Roots / cytology
  • Plant Roots / enzymology
  • Plant Roots / microbiology
  • Plants, Genetically Modified / enzymology
  • Plants, Genetically Modified / genetics
  • Plants, Genetically Modified / microbiology
  • Plants, Toxic*
  • Proton-Translocating ATPases / analysis
  • Proton-Translocating ATPases / genetics*
  • Tobacco / enzymology
  • Tobacco / genetics*
  • Tobacco / microbiology

Substances

  • Proton-Translocating ATPases