scholarly journals Root Microbiome Modulates Plant Growth Promotion Induced by Low Doses of Glyphosate

2020 ◽  
Author(s):  
Dario Ramirez-Villacis
Keyword(s):  
Plant Growth ◽  
Plant Growth Promotion ◽  
Growth Promotion ◽  
Low Doses ◽  
Root Microbiome

scholarly journals Root Microbiome Modulates Plant Growth Promotion Induced by Low Doses of Glyphosate

mSphere ◽  
2020 ◽  
Vol 5 (4) ◽  
Author(s):  
Dario X. Ramirez-Villacis ◽  
Omri M. Finkel ◽  
Isai Salas-González ◽  
Connor R. Fitzpatrick ◽  
Jeffery L. Dangl ◽  
...  
Keyword(s):  
Plant Growth ◽  
Root Growth ◽  
Growth Inhibition ◽  
Growth Promotion ◽  
Action Spectrum ◽  
Dry Weight ◽  
Agricultural Fields ◽  
Low Doses ◽  
Shoot Dry Weight ◽  
Root Microbiome

ABSTRACT Glyphosate is a commonly used herbicide with a broad action spectrum. However, at sublethal doses, glyphosate can induce plant growth, a phenomenon known as hormesis. Most glyphosate hormesis studies have been performed under microbe-free or reduced-microbial-diversity conditions; only a few were performed in open systems or agricultural fields, which include a higher diversity of soil microorganisms. Here, we investigated how microbes affect the hormesis induced by low doses of glyphosate. To this end, we used Arabidopsis thaliana and a well-characterized synthetic bacterial community of 185 strains (SynCom) that mimics the root-associated microbiome of Arabidopsis. We found that a dose of 3.6 × 10−6 g acid equivalent/liter (low dose of glyphosate, or LDG) produced an ∼14% increase in the shoot dry weight (i.e., hormesis) of uninoculated plants. Unexpectedly, in plants inoculated with the SynCom, LDG reduced shoot dry weight by ∼17%. We found that LDG enriched two Firmicutes and two Burkholderia strains in the roots. These specific strains are known to act as root growth inhibitors (RGI) in monoassociation assays. We tested the link between RGI and shoot dry weight reduction in LDG by assembling a new synthetic community lacking RGI strains. Dropping RGI strains out of the community restored growth induction by LDG. Finally, we showed that individual RGI strains from a few specific phyla were sufficient to switch the response to LDG from growth promotion to growth inhibition. Our results indicate that glyphosate hormesis was completely dependent on the root microbiome composition, specifically on the presence of root growth inhibitor strains. IMPORTANCE Since the introduction of glyphosate-resistant crops, glyphosate has become the most common and widely used herbicide around the world. Due to its intensive use and ability to bind to soil particles, it can be found at low concentrations in the environment. The effect of these remnants of glyphosate in plants has not been broadly studied; however, glyphosate 1,000 to 100,000 times less concentrated than the recommended field dose promoted growth in several species in laboratory and greenhouse experiments. However, this effect is rarely observed in agricultural fields, where complex communities of microbes have a central role in the way plants respond to external cues. Our study reveals how root-associated bacteria modulate the responses of Arabidopsis to low doses of glyphosate, shifting between growth promotion and growth inhibition.

Inside the root microbiome: Bacterial root endophytes and plant growth promotion

2013 ◽  
Vol 100 (9) ◽  
pp. 1738-1750 ◽  
Author(s):  
Jonathan R. Gaiero ◽  
Crystal A. McCall ◽  
Karen A. Thompson ◽  
Nicola J. Day ◽  
Anna S. Best ◽  
...  
Keyword(s):  
Plant Growth ◽  
Plant Growth Promotion ◽  
Growth Promotion ◽  
Root Endophytes ◽  
Root Microbiome

scholarly journals Genome Mining and Evaluation of the Biocontrol Potential of Pseudomonas fluorescens BRZ63, a New Endophyte of Oilseed Rape (Brassica napus L.) against Fungal Pathogens

2020 ◽  
Vol 21 (22) ◽  
pp. 8740
Author(s):  
Daria Chlebek ◽  
Artur Pinski ◽  
Joanna Żur ◽  
Justyna Michalska ◽  
Katarzyna Hupert-Kocurek
Keyword(s):  
Brassica Napus ◽  
Plant Growth ◽  
Pseudomonas Fluorescens ◽  
Oilseed Rape ◽  
Plant Growth Promotion ◽  
Fungal Pathogens ◽  
Growth Promotion ◽  
Genome Mining ◽  
Plant Colonization ◽  
Brassica Napus L

Endophytic bacteria hold tremendous potential for use as biocontrol agents. Our study aimed to investigate the biocontrol activity of Pseudomonas fluorescens BRZ63, a new endophyte of oilseed rape (Brassica napus L.) against Rhizoctonia solani W70, Colletotrichum dematium K, Sclerotinia sclerotiorum K2291, and Fusarium avenaceum. In addition, features crucial for biocontrol, plant growth promotion, and colonization were assessed and linked with the genome sequences. The in vitro tests showed that BRZ63 significantly inhibited the mycelium growth of all tested pathogens and stimulated germination and growth of oilseed rape seedlings treated with fungal pathogens. The BRZ63 strain can benefit plants by producing biosurfactants, siderophores, indole-3-acetic acid (IAA), 1-aminocyclopropane-1-carboxylate (ACC) deaminase, and ammonia as well as phosphate solubilization. The abilities of exopolysaccharide production, autoaggregation, and biofilm formation additionally underline its potential to plant colonization and hence biocontrol. The effective colonization properties of the BRZ63 strain were confirmed by microscopy observations of EGFP-expressing cells colonizing the root surface and epidermal cells of Arabidopsis thaliana Col-0. Genome mining identified many genes related to the biocontrol process, such as transporters, siderophores, and other secondary metabolites. All analyses revealed that the BRZ63 strain is an excellent endophytic candidate for biocontrol of various plant pathogens and plant growth promotion.

scholarly journals Streptomyces consortia-mediated plant defense against Fusarium wilt and plant growth-promotion in chickpea

2021 ◽  
pp. 104961
Author(s):  
Sravani Ankati ◽  
Vadlamudi Srinivas ◽  
Sambangi Pratyusha ◽  
Subramaniam Gopalakrishnan
Keyword(s):  
Plant Growth ◽  
Plant Defense ◽  
Fusarium Wilt ◽  
Plant Growth Promotion ◽  
Growth Promotion

scholarly journals Effect of Co-Inoculation of Bacillus sp. Strain with Bacterial Endophytes on Plant Growth and Colonization in Tomato Plant (Solanum lycopersicum)

2021 ◽  
Vol 12 (2) ◽  
pp. 480-490
Author(s):  
Ahsanul Salehin ◽  
Ramesh Raj Puri ◽  
Md Hafizur Rahman Hafiz ◽  
Kazuhito Itoh
Keyword(s):  
Plant Growth ◽  
Solanum Lycopersicum ◽  
Plant Growth Promotion ◽  
Tomato Plant ◽  
Growth Promotion ◽  
Growth Parameters ◽  
The Other ◽  
Time Interval ◽  
Bacillus Sp ◽  
F 33

Colonization of a biofertilizer Bacillus sp. OYK strain, which was isolated from a soil, was compared with three rhizospheric and endophytic Bacillus sp. strains to evaluate the colonization potential of the Bacillus sp. strains with a different origin. Surface-sterilized seeds of tomato (Solanum lycopersicum L. cv. Chika) were sown in the sterilized vermiculite, and four Bacillus sp. strains were each inoculated onto the seed zone. After cultivation in a phytotron, plant growth parameters and populations of the inoculants in the root, shoot, and rhizosphere were determined. In addition, effects of co-inoculation and time interval inoculation of Bacillus sp. F-33 with the other endophytes were examined. All Bacillus sp. strains promoted plant growth except for Bacillus sp. RF-37, and populations of the rhizospheric and endophytic Bacillus sp. strains were 1.4–2.8 orders higher in the tomato plant than that of Bacillus sp. OYK. The plant growth promotion by Bacillus sp. F-33 was reduced by co-inoculation with the other endophytic strains: Klebsiella sp. Sal 1, Enterobacter sp. Sal 3, and Herbaspirillum sp. Sal 6., though the population of Bacillus sp. F-33 maintained or slightly decreased. When Klebsiella sp. Sal 1 was inoculated after Bacillus sp. F-33, the plant growth-promoting effects by Bacillus sp. F-33 were reduced without a reduction of its population, while when Bacillus sp. F-33 was inoculated after Klebsiella sp. Sal 1, the effects were increased in spite of the reduction of its population. Klebsiella sp. Sal 1 colonized dominantly under both conditions. The higher population of rhizospheric and endophytic Bacillus sp. in the plant suggests the importance of the origin of the strains for their colonization. The plant growth promotion and colonization potentials were independently affected by the co-existing microorganisms.

Potential for plant growth promotion of Kocuria arsenatis Strain ST19 on tomato under salt stress conditions

2021 ◽  
Vol 138 ◽  
pp. 94-104
Author(s):  
Guendouz Dif ◽  
Hadj Ahmed Belaouni ◽  
Yacine Goudjal ◽  
Amine Yekkour ◽  
Nadjette Djemouai ◽  
...  
Keyword(s):  
Salt Stress ◽  
Plant Growth ◽  
Plant Growth Promotion ◽  
Growth Promotion ◽  
Stress Conditions
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