Skip to main content

ORIGINAL RESEARCH article

Front. Plant Sci.
Sec. Plant Symbiotic Interactions
Volume 15 - 2024 | doi: 10.3389/fpls.2024.1469676

Gluconacetobacter diazotrophicus AZ0019 requires functional nifD gene for optimal plant growth promotion in tomato plants

Provisionally accepted
Michele Pallucchini Michele Pallucchini 1,2,3Martina Franchini Martina Franchini 1,2,3Enas M. El-Ballat Enas M. El-Ballat 1,4Nathalie Narraidoo Nathalie Narraidoo 2Benjamin Pointer- Gleadhill Benjamin Pointer- Gleadhill 1Matthew J. Palframan Matthew J. Palframan 5Christopher J. Hayes Christopher J. Hayes 1David Dent David Dent 6Edward C. Cocking Edward C. Cocking 1Michele Perazzolli Michele Perazzolli 3,7Rupert G. Fray Rupert G. Fray 1Phil j. Hill Phil j. Hill 1*
  • 1 University of Nottingham, Nottingham, United Kingdom
  • 2 Azotic Technologies Ltd, York, United Kingdom
  • 3 Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige, Italy
  • 4 Tanta University, Faculty of Science, Tanta, Egypt
  • 5 University of Wolverhampton, Wolverhampton, United Kingdom
  • 6 The Sustainable Nitrogen Foundation, Saham Toney, United Kingdom
  • 7 Centre Agriculture Food Environment (C3A), University of Trento, San Michele all'Adige, Italy

The final, formatted version of the article will be published soon.

    The nitrogen fixing diazotroph Gluconacetobacter diazotrophicus is a plant growth promoting bacterium able to colonise a wide range of host plants and is marketed commercially as a biofertiliser. The aims of this study were to investigate if biological nitrogen fixation (BNF) competency affects the growth promotion of inoculated tomato plants and to describe the colonisation mechanism of this bacterium in dicot systems.G. diazotrophicus wild type (Gd WT) or a nitrogen fixation impaired strain (Gd nifD -) were applied to hydroponically grown tomato plants in either the absence or presence of nitrogen.Phenotypic and colonisation data were collected 15 days post inoculation (dpi). qPCR analyses and tagged strains of G.diazotrophicus were employed to quantify and visualise the localisation of both Gd WT and Gd nifD -cells interacting with the plant.Inoculation with Gd WT strain led to increased plant height, fresh weight and chlorophyll content under both nitrogen limited and replete conditions. Inoculation with the Gd nifD -strain resulted in lower increases in fresh weight compared to the wild type bacterium, although significantly higher than the control, and no chlorophyll content increase. The two strains showed similar plant colonisation levels under both nitrogen conditions, suggesting that their effect cannot to be ascribed to a differential colonisation capability.These results indicate that a functional nifD gene is a fundamental requirement for optimal plant growth promotion (PGP) by G. diazotrophicus.

    Keywords: Nitrogen Fixation, plant growth promotion, Tomato, Hydroponics, Gluconacetobacter diazotrophicus

    Received: 24 Jul 2024; Accepted: 04 Nov 2024.

    Copyright: © 2024 Pallucchini, Franchini, El-Ballat, Narraidoo, Pointer- Gleadhill, Palframan, Hayes, Dent, Cocking, Perazzolli, Fray and Hill. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence: Phil j. Hill, University of Nottingham, Nottingham, United Kingdom

    Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.