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Soybean Nodule-Associated Non-Rhizobial Bacteria Inhibit Plant Pathogens and Induce Growth Promotion in Tomato

The root nodules are a unique environment formed on legume roots through a highly specific symbiotic relationship between leguminous plants and nodule-inducing bacteria. Previously, Rhizobia were presumed to be the only group of bacteria residing within nodules. However, recent studies discovered di...

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Autores principales: Tokgöz, Serkan, Lakshman, Dilip K., Ghozlan, Mahmoud H., Pinar, Hasan, Roberts, Daniel P., Mitra, Amitava
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7694458/
https://www.ncbi.nlm.nih.gov/pubmed/33167465
http://dx.doi.org/10.3390/plants9111494
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author Tokgöz, Serkan
Lakshman, Dilip K.
Ghozlan, Mahmoud H.
Pinar, Hasan
Roberts, Daniel P.
Mitra, Amitava
author_facet Tokgöz, Serkan
Lakshman, Dilip K.
Ghozlan, Mahmoud H.
Pinar, Hasan
Roberts, Daniel P.
Mitra, Amitava
author_sort Tokgöz, Serkan
collection PubMed
description The root nodules are a unique environment formed on legume roots through a highly specific symbiotic relationship between leguminous plants and nodule-inducing bacteria. Previously, Rhizobia were presumed to be the only group of bacteria residing within nodules. However, recent studies discovered diverse groups of bacteria within the legume nodules. In this report soybean nodule-associated bacteria were studied in an effort to identify beneficial bacteria for plant disease control and growth promotion. Analysis of surface-sterilized single nodules showed bacterial diversity of the nodule microbiome. Five hundred non-rhizobial colonies from 10 nodules, 50 colonies per nodule, were tested individually against the tomato wilt causing bacterial pathogen Clavibacter michiganensis subsp. michiganensis (Cmm) for inhibition of pathogen growth. From the initial screening, 54 isolates were selected based on significant growth inhibition of Cmm. These isolates were further tested in vitro on another bacterial pathogen Pseudomonas syringae pv. tomato (Pst) and two fungal pathogens Rhizoctonia solani and Sclerotinia sclerotiorum. Bacterial metabolites were extracted from 15 selected isolates with ethanol and tested against pathogen Cmm and Pst. These isolates were identified by using MALDI-TOF mass spectrometry and 16S rRNA gene sequencing. Pseudomonas spp. were the dominant soybean nodule-associated non-rhizobial bacterial group. Several isolates imparted significant protection against pathogens and/or plant growth promotion on tomato seedlings. The most promising nodule-associated bacterial isolate that suppressed both Cmm and Pst in vitro and Pst in tomato seedlings was identified as a Proteus species. Isolation and identification of beneficial nodule-associated bacteria established the foundation for further exploration of potential nodule-associated bacteria for plant protection and growth promotion.
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spelling pubmed-76944582020-11-28 Soybean Nodule-Associated Non-Rhizobial Bacteria Inhibit Plant Pathogens and Induce Growth Promotion in Tomato Tokgöz, Serkan Lakshman, Dilip K. Ghozlan, Mahmoud H. Pinar, Hasan Roberts, Daniel P. Mitra, Amitava Plants (Basel) Article The root nodules are a unique environment formed on legume roots through a highly specific symbiotic relationship between leguminous plants and nodule-inducing bacteria. Previously, Rhizobia were presumed to be the only group of bacteria residing within nodules. However, recent studies discovered diverse groups of bacteria within the legume nodules. In this report soybean nodule-associated bacteria were studied in an effort to identify beneficial bacteria for plant disease control and growth promotion. Analysis of surface-sterilized single nodules showed bacterial diversity of the nodule microbiome. Five hundred non-rhizobial colonies from 10 nodules, 50 colonies per nodule, were tested individually against the tomato wilt causing bacterial pathogen Clavibacter michiganensis subsp. michiganensis (Cmm) for inhibition of pathogen growth. From the initial screening, 54 isolates were selected based on significant growth inhibition of Cmm. These isolates were further tested in vitro on another bacterial pathogen Pseudomonas syringae pv. tomato (Pst) and two fungal pathogens Rhizoctonia solani and Sclerotinia sclerotiorum. Bacterial metabolites were extracted from 15 selected isolates with ethanol and tested against pathogen Cmm and Pst. These isolates were identified by using MALDI-TOF mass spectrometry and 16S rRNA gene sequencing. Pseudomonas spp. were the dominant soybean nodule-associated non-rhizobial bacterial group. Several isolates imparted significant protection against pathogens and/or plant growth promotion on tomato seedlings. The most promising nodule-associated bacterial isolate that suppressed both Cmm and Pst in vitro and Pst in tomato seedlings was identified as a Proteus species. Isolation and identification of beneficial nodule-associated bacteria established the foundation for further exploration of potential nodule-associated bacteria for plant protection and growth promotion. MDPI 2020-11-05 /pmc/articles/PMC7694458/ /pubmed/33167465 http://dx.doi.org/10.3390/plants9111494 Text en © 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Tokgöz, Serkan
Lakshman, Dilip K.
Ghozlan, Mahmoud H.
Pinar, Hasan
Roberts, Daniel P.
Mitra, Amitava
Soybean Nodule-Associated Non-Rhizobial Bacteria Inhibit Plant Pathogens and Induce Growth Promotion in Tomato
title Soybean Nodule-Associated Non-Rhizobial Bacteria Inhibit Plant Pathogens and Induce Growth Promotion in Tomato
title_full Soybean Nodule-Associated Non-Rhizobial Bacteria Inhibit Plant Pathogens and Induce Growth Promotion in Tomato
title_fullStr Soybean Nodule-Associated Non-Rhizobial Bacteria Inhibit Plant Pathogens and Induce Growth Promotion in Tomato
title_full_unstemmed Soybean Nodule-Associated Non-Rhizobial Bacteria Inhibit Plant Pathogens and Induce Growth Promotion in Tomato
title_short Soybean Nodule-Associated Non-Rhizobial Bacteria Inhibit Plant Pathogens and Induce Growth Promotion in Tomato
title_sort soybean nodule-associated non-rhizobial bacteria inhibit plant pathogens and induce growth promotion in tomato
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7694458/
https://www.ncbi.nlm.nih.gov/pubmed/33167465
http://dx.doi.org/10.3390/plants9111494
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