Toxicity of seed-applied pesticides to Azospirillum spp.: an approach based on bacterial count in the maize rhizosphere

The objective of this work was to investigate the impact of pesticides on the survival of the plant growth- promoting bacteria Azospirillum in the surface of coated seeds as well as in the maize rhizosphere. Our results showed that the greater the time that the bacteria are in contact with the seed surface, the higher the cell mortality. In uncoated maize seeds, inoculation increased bacterial concentration in root tissues and ensured superior plant growth up to 12 hours of Azospirillum contact with the seed surface, while for the coated seeds, a similar performance was observed only up to six hours of exposure.

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Compatibility of Azospirillum brasilense with Pesticides Used for Treatment of Maize Seeds

International Journal of Microbiology ◽

10.1155/2020/8833879 ◽

2020 ◽

Vol 2020 ◽

pp. 1-8

Author(s):

Mariana S. Santos ◽

Artur B. L. Rondina ◽

Marco A. Nogueira ◽

Mariangela Hungria

Keyword(s):

Plant Growth ◽

Root Hair ◽

Azospirillum Brasilense ◽

Plant Protection ◽

Plant Growth Promoting Bacteria ◽

Root Volume ◽

Maize Seeds ◽

Plant Growth Promoting ◽

Growth Promoting

Seed treatment with chemical pesticides is commonly used as an initial plant protection procedure against pests and diseases. However, the use of such chemicals may impair the survival and performance of beneficial microorganisms introduced via inoculants, such as the plant growth-promoting bacterium Azospirillum brasilense. We assessed the compatibility between the most common pesticide used in Brazil for the treatment of maize seeds, composed of two fungicides, and one insecticide, with the commercial strains Ab-V5 and Ab-V6 of A. brasilense, and evaluated the impacts on initial plant development. The toxicity of the pesticide to A. brasilense was confirmed, with an increase in cell mortality after only 24 hours of exposure in vitro. Seed germination and seedling growth were not affected neither by the A. brasilense nor by the pesticide. However, under greenhouse conditions, the pesticide affected root volume and dry weight and root-hair incidence, but the toxicity was alleviated by the inoculation with A. brasilense for the root volume and root-hair incidence parameters. In maize seeds inoculated with A. brasilense, the pesticide negatively affected the number of branches, root-hair incidence, and root-hair length. Therefore, new inoculant formulations with cell protectors and the development of compatible pesticides should be searched to guarantee the benefits of inoculation with plant growth-promoting bacteria.

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The Contrivance of Plant Growth Promoting Microbes to Mitigate Climate Change Impact in Agriculture

Microorganisms ◽

10.3390/microorganisms9091841 ◽

2021 ◽

Vol 9 (9) ◽

pp. 1841

Author(s):

Angelika Fiodor ◽

Surender Singh ◽

Kumar Pranaw

Keyword(s):

Climate Change ◽

Plant Growth ◽

Global Climate ◽

Acc Deaminase ◽

Crop Productivity ◽

Plant Growth Promoting Bacteria ◽

Hormone Synthesis ◽

Plant Growth Promoting ◽

Growth Promoting ◽

The Impact

Combating the consequences of climate change is extremely important and critical in the context of feeding the world’s population. Crop simulation models have been extensively studied recently to investigate the impact of climate change on agricultural productivity and food security. Drought and salinity are major environmental stresses that cause changes in the physiological, biochemical, and molecular processes in plants, resulting in significant crop productivity losses. Excessive use of chemicals has become a severe threat to human health and the environment. The use of beneficial microorganisms is an environmentally friendly method of increasing crop yield under environmental stress conditions. These microbes enhance plant growth through various mechanisms such as production of hormones, ACC deaminase, VOCs and EPS, and modulate hormone synthesis and other metabolites in plants. This review aims to decipher the effect of plant growth promoting bacteria (PGPB) on plant health under abiotic soil stresses associated with global climate change (viz., drought and salinity). The application of stress-resistant PGPB may not only help in the combating the effects of abiotic stressors, but also lead to mitigation of climate change. More thorough molecular level studies are needed in the future to assess their cumulative influence on plant development.

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Initial performance of maize in response to humic acids and plant growth-promoting bacteria

Revista CERES ◽

10.1590/0034-737x201865030007 ◽

2018 ◽

Vol 65 (3) ◽

pp. 271-277 ◽

Cited By ~ 2

Author(s):

Raphael Oliveira de Melo ◽

Hend Pereira de Oliveira ◽

Klever Cristiano Silveira ◽

Lílian Estrela Borges Baldotto ◽

Marihus Altoé Baldotto

Keyword(s):

Plant Growth ◽

Humic Acids ◽

Most Probable Number ◽

Plant Growth Promoting Bacteria ◽

Probable Number ◽

Combined Application ◽

Maize Seeds ◽

Burkholderia Gladioli ◽

Plant Growth Promoting ◽

Growth Promoting

ABSTRACT Seed treatment with inoculants based on plant growth-promoting bacteria (PGPB) or the application of humic acids (HA) may increase the productivity of plants of agricultural interest. The hypothesis of this work is that it is possible to combine the effect of plant growth promoting characteristic of HA with the inoculation of PGPB selected strains in the treatment of maize seeds. Thus, providing superior responses than in single applications of both in the initial maize development. To meet this purpose, we conducted isolated application of HA or PGPB inoculation of Burkholderia gladioli and Rhizobium cellulosilyticum, and the combined application of PGPB and HA for treatment of maize seeds. At the end of the experiment (45 days after germination), the plants were evaluated biometrically, nutritionally and a bacteria count was performed in plants using the Most Probable Number technique. The results showed that it is possible to combine the effects of HA with the inoculation of selected strains of PGPB, obtaining superior responses to the isolated application of both. Thus, the use of HA-based bio-stimulants in combination with PGPB is positive and complementary compared to inputs generally used in the treatment of maize seeds.

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Maize response to inoculation with strains of plant growth-promoting bactéria

Revista Brasileira de Engenharia Agrícola e Ambiental ◽

10.1590/1807-1929/agriambi.v20n7p606-611 ◽

2016 ◽

Vol 20 (7) ◽

pp. 606-611 ◽

Cited By ~ 4

Author(s):

Janaína Dartora ◽

Vandeir F. Guimarães ◽

Cid R. J. Menezes ◽

Mariângela B. Freiberger ◽

Gustavo Castoldi ◽

...

Keyword(s):

Plant Growth ◽

Block Design ◽

N Fertilization ◽

Plant Growth Promoting Bacteria ◽

Maize Seeds ◽

Randomized Block Design ◽

Plant Growth Promoting ◽

Growth Promoting ◽

Maize Response ◽

Rhizobium Sp

ABSTRACT The aim of this study was to evaluate the response of maize to inoculation with strains of plant growth-promoting bacteria (PGPB) in two cultivation years. The experiment was set in a randomized block design with four replicates in two cultivation years (2012/13 and 2013/14). The treatments consisted of PGPB inoculation: control (without N and without inoculation); 30 kg of N ha-1 at sowing (N1); 160 kg of N ha-1 (N1 + 130 kg of N ha-1 as top-dressing); N1 + A. brasilense, Ab-V5; N1 + A. brasilense, HM053; N1 + Azospirillum sp. L26; N1 + Azospirillum sp. L27; N1 + Enhydrobacter sp. 4331; N1 + Rhizobium sp. 8121. Basal stem diameter, plant height, leaf area, shoot dry matter and yield were evaluated. The strain of Rhizobium sp. 8121and the isolate Azospirillum sp. L26 associated with 30 kg of N ha-1 at sowing promoted yields equivalent to that of the N fertilization of 160 kg ha-1, demonstrating the potential to be used in the inoculation of maize seeds.

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Bacterial Consortium for Improved Maize (Zea mays L.) Production

Microorganisms ◽

10.3390/microorganisms7110519 ◽

2019 ◽

Vol 7 (11) ◽

pp. 519 ◽

Cited By ~ 6

Author(s):

Oluwaseyi Samuel Olanrewaju ◽

Olubukola Oluranti Babalola

Keyword(s):

Plant Growth ◽

Growth Parameters ◽

Block Design ◽

Bacterial Consortium ◽

Microbial Consortia ◽

Plant Growth Promoting Bacteria ◽

Promoting Effect ◽

Maize Seeds ◽

Plant Growth Promoting ◽

Growth Promoting

The ever-increasing human population is a major concern for food security. Maize is the third largest most important food crop. The major problems of cultivation arise from urbanization and land pollution. This reduces the amount of land available for agriculture. The use of chemicals in agriculture is not environmentally friendly. Thus, plant growth-promoting bacteria (PGPB) have been proposed as alternatives. This study aims to test the growth-promoting effect of maize inoculated with six indigenous PGPB isolates. These isolates were assayed for various biochemical and plant growth-promoting activities. They were also assayed for biocontrol activities. Based on the results, six isolates viz A1, A18, A29, NWU4, NWU14, and NWU198 were used to inoculate maize seeds. The inoculated seeds were tried out on the field. A randomized block design was used. PGPB used were in single, consortia of two, and three organisms. The length of the leaves, roots, and stem, plant height, numbers of leaves, and weight of 100 seeds were taken at the fourth and eighth weeks after planting. Microbial consortia increased growth parameters compared to single inoculant treatments. Thus, they can be of advantage in the eradication of low yield. They can also serve as reliable alternatives to chemical fertilizers.

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The impact of plant growth promoting bacteria (PGPB) on the development of phytopathogenic fungi

Folia Biologica et Oecologica ◽

10.2478/fobio-2014-0008 ◽

2014 ◽

Vol 10 ◽

pp. 107-112

Author(s):

Anna Grobelak ◽

Anna Napora ◽

Małgorzata Kacprzak

Keyword(s):

Sewage Sludge ◽

Plant Growth ◽

Fusarium Oxysporum ◽

Alternaria Alternata ◽

Phytopathogenic Fungi ◽

Plant Growth Promoting Bacteria ◽

Antifungal Properties ◽

Plant Growth Promoting ◽

Growth Promoting ◽

The Impact

The main purpose of this study was to evaluate impact of plant growth promoting bacteria (PGPB) on the development of phytopathogenic fungi and correlate it with a potential effects on the growth of plants under unfavorable conditions, in order to improve the efficiency of a phytoremediation process. The conducted research focused on the antifungal properties of PGPB. In this study, 51 isolates of bacteria were obtained after diversified disinfection time from plants growing on soil after sewage sludge amendment. The results revealed that some isolated bacteria, mainly endophytic ones, inhibited the development of Fusarium oxysporum, F. culmorum and Alternaria alternata.

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Isolation and identification of plant growth-promoting bacteria associated with tall fescue

Proceedings of the New Zealand Grassland Association ◽

10.33584/jnzg.2009.71.2751 ◽

2009 ◽

pp. 211-216 ◽

Cited By ~ 5

Author(s):

J. Monk ◽

E. Gerard ◽

S. Young ◽

K. Widdup ◽

M. O'Callaghan

Keyword(s):

New Zealand ◽

Plant Growth ◽

Tall Fescue ◽

Festuca Arundinacea ◽

Plant Growth Promoting Bacteria ◽

Beneficial Bacteria ◽

Isolation And Identification ◽

Naturally Occurring ◽

Plant Growth Promoting ◽

Growth Promoting

Tall fescue (Festuca arundinacea) is a useful alternative to ryegrass in New Zealand pasture but it is slow to establish. Naturally occurring beneficial bacteria in the rhizosphere can improve plant growth and health through a variety of direct and indirect mechanisms. Keywords: rhizosphere, endorhiza, auxin, siderophore, P-solubilisation

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