Plant and Soil

, Volume 356, Issue 1, pp 165–174

The Vicia sativa spp. nigra - Rhizobium leguminosarum bv. viciae symbiotic interaction is improved by Azospirillum brasilense

  • Lara Star
  • Ofra Matan
  • Marta S. Dardanelli
  • Yoram Kapulnik
  • Saul Burdman
  • Yaacov Okon
Regular Article

DOI: 10.1007/s11104-010-0713-7

Cite this article as:
Star, L., Matan, O., Dardanelli, M.S. et al. Plant Soil (2012) 356: 165. doi:10.1007/s11104-010-0713-7

Abstract

This study aimed to examine the effects of inoculation with wild type (Sp7) and mutant strains of Azospirillum brasilense on the Vicia sativa spp. nigra (vetch)-Rhizobium leguminosarum bv. viciae (Rlv) symbiosis. The A. brasilense mutants were ipdC- and napA-, impaired in indole pyruvate decarboxylase and periplasmic nitrate reductase, respectively; and acdS+, carrying the ACC deaminase gene. Inoculations were done in pots, pouches and hydroponics and we measured shoot and root weight parameters as well as effects on root morphology and nod gene induction ability by roots. In pots, wild type Sp7 and the acdS+ strain, but ipdC- and napA- mutants, lead to an increase in root hair density, 3–4 cm above the root tip. In pouches, combined inoculation with Rlv and strains Sp7, acdS+ or ipdC-, but napA-, increased shoot dry matter and nodulation relative to Rlv alone. In a hydroponic system, co-inoculation with strains Sp7 or acdS+, but with ipdC- and napA- mutants, enhanced root secretion of nod gene-inducing flavonoids in comparison with Rlv-inoculated plants. These results support that auxin production by A. brasilense has a positive effect on root secretion of nod gene-inducing flavonoids and auxin absorption activity by the plant.

Keywords

Co-inoculation Flavonoids nod gene expression Auxin Nitric oxide 

Copyright information

© Springer Science+Business Media B.V. 2011

Authors and Affiliations

  • Lara Star
    • 1
  • Ofra Matan
    • 1
  • Marta S. Dardanelli
    • 2
  • Yoram Kapulnik
    • 3
  • Saul Burdman
    • 1
  • Yaacov Okon
    • 1
  1. 1.Department of Plant Pathology and Microbiology and the Otto Warburg Minerva Center for Agricultural Biotechnology, The Robert H. Smith Faculty of Agriculture, Food and EnvironmentThe Hebrew University of JerusalemRehovotIsrael
  2. 2.Departamento de Biología Molecular, Facultad de Ciencias Exactas, Físico-Químicas y NaturalesUniversidad Nacional de Río CuartoRio CuartoArgentina
  3. 3.Agronomy and Natural Research Department, Institute of Plant Sciences, Agricultural Research OrganizationThe Volcani CenterBet DaganIsrael