Auxin-Producing Bacteria Used as Microbial Biostimulants Improve the Growth of Tomato (<i>Solanum lycopersicum</i> L.) Seedlings in Hydroponic Systems

Seven auxin-producing endophytic bacterial strains (<i>Azospirillum</i> spp., <i>Methylobacterium symbioticum</i>, <i>Bacillus</i> spp.), and two different combinations of these strains were used to verify their influence on tomato during germination and developme...

Full description

Saved in:
Bibliographic Details
Main Authors: Livia Pappalettere, Susanna Bartolini, Annita Toffanin
Format: Article
Language:English
Published: MDPI AG 2024-08-01
Series:BioTech
Subjects:
Online Access:https://www.mdpi.com/2673-6284/13/3/32
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850258339898851328
author Livia Pappalettere
Susanna Bartolini
Annita Toffanin
author_facet Livia Pappalettere
Susanna Bartolini
Annita Toffanin
author_sort Livia Pappalettere
collection DOAJ
description Seven auxin-producing endophytic bacterial strains (<i>Azospirillum</i> spp., <i>Methylobacterium symbioticum</i>, <i>Bacillus</i> spp.), and two different combinations of these strains were used to verify their influence on tomato during germination and development in hydroponic conditions where, as a novelty for Canestrino di Lucca cultivar, endophytic bacteria were inoculated. To emphasize the presence of bacterial auxins in roots and stems of seedlings, both in situ staining qualitative assessment and quantitative analysis were carried out. Moreover, hypogeal and epigeal growth of the plantlets were measured, and correlation analyses were conducted to examine the relationship between the amount of indolacetic acid (IAA) produced by the bacterial strains and root and stem parameters. Plantlets treated with microbial inoculants showed a significant increase in the survival rate compared to the control treatment. The best results as IAA producers were from <i>Azospirillum baldaniorum</i> Sp245 and <i>A. brasilense</i> Cd, which also induced significant root growth. On the other hand, <i>Bacillus amyloliquefaciens</i> and <i>B. licheniformis</i> induced the best rates in stem growth. These findings highlight the potential for using endophytic bacterial strains in a hydroponic co-cultivation system that enables inoculating plantlets, at an early stage of growth (5 days old).
format Article
id doaj-art-1d7f38dd2e104fc3b9466bf375817a9e
institution OA Journals
issn 2673-6284
language English
publishDate 2024-08-01
publisher MDPI AG
record_format Article
series BioTech
spelling doaj-art-1d7f38dd2e104fc3b9466bf375817a9e2025-08-20T01:56:11ZengMDPI AGBioTech2673-62842024-08-011333210.3390/biotech13030032Auxin-Producing Bacteria Used as Microbial Biostimulants Improve the Growth of Tomato (<i>Solanum lycopersicum</i> L.) Seedlings in Hydroponic SystemsLivia Pappalettere0Susanna Bartolini1Annita Toffanin2Institute of Crop Science, Sant’Anna School of Advanced Studies, Piazza Martiri della Libertà 33, 56127 Pisa, ItalyInstitute of Crop Science, Sant’Anna School of Advanced Studies, Piazza Martiri della Libertà 33, 56127 Pisa, ItalyDepartment of Agriculture Food and Environment (DAFE), University of Pisa, Via del Borghetto 80, 56124 Pisa, ItalySeven auxin-producing endophytic bacterial strains (<i>Azospirillum</i> spp., <i>Methylobacterium symbioticum</i>, <i>Bacillus</i> spp.), and two different combinations of these strains were used to verify their influence on tomato during germination and development in hydroponic conditions where, as a novelty for Canestrino di Lucca cultivar, endophytic bacteria were inoculated. To emphasize the presence of bacterial auxins in roots and stems of seedlings, both in situ staining qualitative assessment and quantitative analysis were carried out. Moreover, hypogeal and epigeal growth of the plantlets were measured, and correlation analyses were conducted to examine the relationship between the amount of indolacetic acid (IAA) produced by the bacterial strains and root and stem parameters. Plantlets treated with microbial inoculants showed a significant increase in the survival rate compared to the control treatment. The best results as IAA producers were from <i>Azospirillum baldaniorum</i> Sp245 and <i>A. brasilense</i> Cd, which also induced significant root growth. On the other hand, <i>Bacillus amyloliquefaciens</i> and <i>B. licheniformis</i> induced the best rates in stem growth. These findings highlight the potential for using endophytic bacterial strains in a hydroponic co-cultivation system that enables inoculating plantlets, at an early stage of growth (5 days old).https://www.mdpi.com/2673-6284/13/3/32endophytic bacteria<i>Azospirillum</i> spp.<i>Bacillus</i> spp.hydroponicIAArhizobacteria
spellingShingle Livia Pappalettere
Susanna Bartolini
Annita Toffanin
Auxin-Producing Bacteria Used as Microbial Biostimulants Improve the Growth of Tomato (<i>Solanum lycopersicum</i> L.) Seedlings in Hydroponic Systems
BioTech
endophytic bacteria
<i>Azospirillum</i> spp.
<i>Bacillus</i> spp.
hydroponic
IAA
rhizobacteria
title Auxin-Producing Bacteria Used as Microbial Biostimulants Improve the Growth of Tomato (<i>Solanum lycopersicum</i> L.) Seedlings in Hydroponic Systems
title_full Auxin-Producing Bacteria Used as Microbial Biostimulants Improve the Growth of Tomato (<i>Solanum lycopersicum</i> L.) Seedlings in Hydroponic Systems
title_fullStr Auxin-Producing Bacteria Used as Microbial Biostimulants Improve the Growth of Tomato (<i>Solanum lycopersicum</i> L.) Seedlings in Hydroponic Systems
title_full_unstemmed Auxin-Producing Bacteria Used as Microbial Biostimulants Improve the Growth of Tomato (<i>Solanum lycopersicum</i> L.) Seedlings in Hydroponic Systems
title_short Auxin-Producing Bacteria Used as Microbial Biostimulants Improve the Growth of Tomato (<i>Solanum lycopersicum</i> L.) Seedlings in Hydroponic Systems
title_sort auxin producing bacteria used as microbial biostimulants improve the growth of tomato i solanum lycopersicum i l seedlings in hydroponic systems
topic endophytic bacteria
<i>Azospirillum</i> spp.
<i>Bacillus</i> spp.
hydroponic
IAA
rhizobacteria
url https://www.mdpi.com/2673-6284/13/3/32
work_keys_str_mv AT liviapappalettere auxinproducingbacteriausedasmicrobialbiostimulantsimprovethegrowthoftomatoisolanumlycopersicumilseedlingsinhydroponicsystems
AT susannabartolini auxinproducingbacteriausedasmicrobialbiostimulantsimprovethegrowthoftomatoisolanumlycopersicumilseedlingsinhydroponicsystems
AT annitatoffanin auxinproducingbacteriausedasmicrobialbiostimulantsimprovethegrowthoftomatoisolanumlycopersicumilseedlingsinhydroponicsystems