IN VITRO FORMATION OF ASSOCIATED BIOFILMS BY TRICHODERMA SPP. AND PLANT GROWTH PROMOTING BACTERIA (PGPB)

The capability to formation of combined biofilms by the fungi from Trichoderma genus and several PGP-bacteria including Pseudomonas extremaustralis, P. koreensis, P. mandelii and Advenella kashmirensis has been demonstrated. The strains of Trichoderma used in the experiment not only exert antagonism to phytopathogenic fungi, but also accelerate the decomposition of plant residues. It was found that microscopic fungi whose mycelial structure offers advantages in reaching and assimilating of nutrient substrates, during their growth can favor to directional moving of bacteria cells. The explored bacterial strains moved along the fungal mycelium on the surface of the medium, and in areas where the medium was absent, the bacteria moved inside the hyphae, leaving them when the mycelium reached the substrate. The findings evidence the potential of considered microorganisms for developing of a new generation multifunctional biopreparation for agriculture, contributing not only to crop yield increase and plant protection against phytopathogenic fungi, but also maintaining soil fertility.

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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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In vitro and in vivo effects of Pseudomonas spp. and Bacillus sp. on Fusarium acuminatum, Botrytis cinerea and Aspergillus niger infecting Cucumber

Pesticidi i fitomedicina ◽

10.2298/pif1503169z ◽

2015 ◽

Vol 30 (3) ◽

pp. 169-178

Author(s):

Jasmina Zdravkovic ◽

Milan Ugrinovic ◽

Milan Zdravkovic ◽

Slavisa Djordjevic ◽

Snezana Pavlovic ◽

...

Keyword(s):

Plant Growth ◽

Plant Protection ◽

Phytopathogenic Fungi ◽

Mineral Fertilizers ◽

Plant Growth Promoting Bacteria ◽

Pseudomonas Sp ◽

Bacillus Sp ◽

Plant Weight ◽

Pseudomonas Spp

Cucumber (Cucumis sativus L) is an important member of the Cucurbitaceae family. Production of healthy nursery is necessary for high-quality production of this crop in greenhouses and in fields. With the idea of minimizing the use of pesticides and mineral fertilizers to preserve soil quality, we investigated the effects of plant growth promoting bacteria (PGPB) on growth promotion and protection of cucumber plants from phytopathogenic fungi. The effects of Pseudomonas spp. strains with different antifungal activities and Bacillus sp. Q10 strain with PGP activity were tested on cucumber plants. Antagonistic activity of Pseudomonas spp. against the growth of several phytopathogenic fungi isolated from cucumber: F. acuminatum, B. cinerea and A. niger, was observed. The influences of overnight cultures, supernatants and heat-stable antifungal factors were tested on the phytopathogenic fungi in vitro. Pseudomonas sp. K35 and K24 strains were more effective than P. chlororaphis Q16 and Pseudomonas sp. K27, showing 70-80% of fungal growth inhibition regardless of culture or fraction applied. The good antagonists that belong to pseudomonads and Bacillus sp. Q10 strain were used as mixtures for estimation of plant growth and health promoting effects on cucumber plants. Growth dynamics differed depending on the applied strain of Pseudomonas sp. The M3 treatment (a mixture of Bacillus sp. Q10 and P. chlororaphis Q16) stimulated the initial phase of growth, while M4 (a mixture of Bacillus sp. Q10 and Pseudomonas sp. K24) resulted in the maximal height at the final measurement. Significant differences in leaf and plant weight (M4), and leaf weight (M5, containing K35 strain) were found after the treatments. No significant differences in chlorophyll and NBI level were observed in any of the tested combinations. The obtained results suggested that M3 was suitable for stimulation of the early phase of cucumber growth, while the mixtures M4 and M5 improved plant protection and stimulated the later phases of cucumber growth.

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Identification and Characterization of a Hexapeptide with Activity Against Phytopathogenic Fungi That Cause Postharvest Decay in Fruits

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi.2000.13.8.837 ◽

2000 ◽

Vol 13 (8) ◽

pp. 837-846 ◽

Cited By ~ 53

Author(s):

Belén López-García ◽

Luis González-Candelas ◽

Enrique Pérez-Payá ◽

Jose F. Marcos

Keyword(s):

Antimicrobial Activity ◽

Amino Acid ◽

Amino Acid Sequence ◽

Plant Protection ◽

Phytopathogenic Fungi ◽

Bacterial Strains ◽

General Sequence ◽

Postharvest Decay ◽

Structure Conservation

A hexapeptide of amino acid sequence Ac-Arg-Lys-Thr-Trp-Phe-Trp-NH 2 was demonstrated to have antimicrobial activity against selected phytopathogenic fungi that cause postharvest decay in fruits. The peptide synthesized with either all D- or all L-amino acids inhibited the in vitro growth of strains of Penicillium italicum, P. digitatum, and Botrytis cinerea, with MICs of 60 to 80 μM and 50% inhibitory concentration (IC50) of 30 to 40 μM. The inhibitory activity of the peptide was both sequence- and fungus-specific since (i) sequence-related peptides lacked activity (including one with five residues identical to the active sequence), (ii) other filamentous fungi (including some that belong to the genus Penicillium) were insensitive to the peptide's antifungal action, and (iii) the peptide did not inhibit the growth of several yeast and bacterial strains assayed. Experiments on P. digitatum identified conidial germination as particularly sensitive to inhibition although mycelial growth was also affected. Our findings suggest that the inhibitory effect is initially driven by the electrostatic interaction of the peptide with fungal components. The antifungal peptide retarded the blue and green mold diseases of citrus fruits and the gray mold of tomato fruits under controlled inoculation conditions, thus providing evidence for the feasibility of using very short peptides in plant protection. This and previous studies with related peptides indicate some degree of peptide amino acid sequence and structure conservation associated with the antimicrobial activity, and suggest a general sequence layout for short antifungal peptides, consisting of one or two positively charged residues combined with aromatic amino acid residues.

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Bioprospecting of elite plant growth-promoting bacteria for the maize crop

Acta Scientiarum Agronomy ◽

10.4025/actasciagron.v42i1.44364 ◽

2020 ◽

Vol 42 ◽

pp. e44364 ◽

Cited By ~ 1

Author(s):

Angela Cristina Ikeda ◽

Daiani Cristina Savi ◽

Mariangela Hungria ◽

Vanessa Kava ◽

Chirlei Glienke ◽

...

Keyword(s):

Plant Growth ◽

Plant Growth Promoting Bacteria ◽

Bacterial Strains ◽

Maize Crop ◽

Agriculture Sustainability ◽

Plant Growth Promoting ◽

Promote Plant Growth ◽

Growth Promoting ◽

Biological Nitrogen

The use of plant growth-promoting bacteria (PGPB), which aims to replace chemical fertilizers and biological control, is a goal for achieving agriculture sustainability. In this scenario, our goal was to identify and evaluate the potential of bacteria isolated from maize roots to promote plant growth and be used as inoculants. We evaluated 173 bacterial strains isolated from the maize (Zea mays L.) rhizosphere for the properties of their PGPB in vitro. Twelve strains were positive for siderophores, indole acetic acid (IAA) production, biological nitrogen fixation (BNF), and phosphate solubilization. Sequence analysis of 16S rRNA identified these strains as belonging to the genera Cellulosimicrobium, Stenotrophomonas, Enterobacter, and Bacillus. The elite strains were evaluated under greenhouse conditions upon the inoculation of two maize hybrids, ATL100 and KWX628. The ability of the isolates to promote plant growth was dependent on the maize genotype; Enterobacter sp. LGMB208 showed the best ability to promote growth of hybrid ATL100, while Enterobacter sp. strains LGMB125, LGMB225, and LGMB274 and Cellulosimicrobium sp. strain LGMB239 showed the best ability to promote growth of hybrid KWX628. The results highlight the potential of bacterial genera little explored as maize PGPB but indicate the need to investigate their interactions with different plant genotypes.

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Synthesis of Biogenic silver nanoparticles using plant growth-promoting bacteria: Potential use as biocontrol agent against phytopathogens

Biomaterials and Polymers Horizon ◽

10.37819/bph.001.01.0130 ◽

2021 ◽

Vol 1 (1) ◽

pp. 22-31

Author(s):

Divya Mittal ◽

Arun Kumar ◽

Bhuvaneshwari Balasubramaniam ◽

Rahul Thakur ◽

Samarjeet Singh Siwal ◽

...

Keyword(s):

Plant Growth ◽

Burkholderia Cepacia ◽

Phytopathogenic Fungi ◽

Plant Growth Promoting Bacteria ◽

Vis Spectroscopy ◽

Silver Nps ◽

Plant Growth Promoting ◽

Growth Promoting ◽

Potential Use

Biogenic nanoparticles (NPs) derived from microbes present an excellent opportunity to deal with various challenges in medicine, diagnosis, environment and agriculture. In the area of agriculture sciences, researchers are facing challenges related to excessive utilization of pesticides which can be answered by utilizing plant growth-promoting (PGP) microbes. Herein, we have employed the culture filtrate of two PBP bacteria strains, Serratia marcescens and Burkholderia cepacia to prepare biogenic silver NPs. The biogenic silver NPs were characterized by various techniques viz. UV-VIS spectroscopy, SEM, XRD and FTIR. The biogenic AgNPs were able to control the growth of phytopathogenic fungi Aspergillus niger, A. fumigatus, Fusarium oxysporum, Pythium sp., and Rosellinia sp. by more than 80% as examined by in vitro growth reduction on agar medium. Very significantly, the growth inhibition of seedlings by phytopathogenic fungi was efficiently rescued using biogenic AgNPs derived from PGP bacteria. These results indicate the potential use of biogenic NPs to reduce the burden of chemical-based pesticides.

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Characterization of plant growth-promoting bacteria inhabiting Vriesea gigantea Gaud. and Tillandsia aeranthos (Loiseleur) L.B. Smith (Bromeliaceae)

Biota Neotropica ◽

10.1590/s1676-06032013000300010 ◽

2013 ◽

Vol 13 (3) ◽

pp. 80-85 ◽

Cited By ~ 8

Author(s):

Adriana Giongo ◽

Anelise Beneduzi ◽

Kelsey Gano ◽

Luciano Kayser Vargas ◽

Laura Utz ◽

...

Keyword(s):

Phosphate Solubilization ◽

Plant Growth Promoting Bacteria ◽

Water Tank ◽

Bacterial Isolates ◽

Bacterial Strains ◽

H Gene ◽

Plant Growth Promoting ◽

High Nutrient Concentration ◽

Water Tanks

Microorganisms that live inside and around a plant can supply it with essential substances, such as phytohormones and essential nutrients. The present investigation aimed to isolate and characterize the phyllosphere, the endophytic, and the water tank bacteria associated with Vriesea gigantea and Tillandsia aeranthos. The bacteria were tested for siderophore and indole-3-acetic acid (IAA) production, phosphate solubilization, and presence of the nif H gene. Genetic diversity of the bacterial isolates was evaluated by rep-PCR. Sixty-eight bacterial strains were isolated from 3 different microhabitats of V. gigantea and from 2 microhabitats of T. aeranthos bromeliad plants. Gram-positive, spore-forming bacilli comprised most bacterial isolates. All isolates produced IAA in vitro in presence of very low amounts of tryptophan. More than 70% of the evaluated bacteria presented the ability of siderophore production and phosphate solubilization, and possessed the nif H gene. It was not possible to distinguish well-defined groups of isolates based on the bromeliad species and microhabitat they inhabit using genetic characterization by rep-PCR. Water tanks presented the most abundant diversity compared with phyllosphere and endophytes, probably due to the high nutrient concentration, which promotes an ideal environment for complex microbial communities.

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Role of Two Plant Growth-Promoting Bacteria in Remediating Cadmium-Contaminated Soil Combined with Miscanthus floridulus (Lab.)

Plants ◽

10.3390/plants10050912 ◽

2021 ◽

Vol 10 (5) ◽

pp. 912

Author(s):

Shuming Liu ◽

Hongmei Liu ◽

Rui Chen ◽

Yong Ma ◽

Bo Yang ◽

...

Keyword(s):

Plant Growth ◽

Contaminated Soils ◽

Translocation Factor ◽

Plant Growth Promoting Bacteria ◽

Bacterial Strains ◽

Pgp Traits ◽

Cd Tolerance ◽

Plant Growth Promoting ◽

Growth Promoting ◽

Cd Translocation

Miscanthus spp. are energy plants and excellent candidates for phytoremediation approaches of metal(loid)s-contaminated soils, especially when combined with plant growth-promoting bacteria. Forty-one bacterial strains were isolated from the rhizosphere soils and roots tissue of five dominant plants (Artemisia argyi Levl., Gladiolus gandavensis Vaniot Houtt, Boehmeria nivea L., Veronica didyma Tenore, and Miscanthus floridulus Lab.) colonizing a cadmium (Cd)-contaminated mining area (Huayuan, Hunan, China). We subsequently tested their plant growth-promoting (PGP) traits (e.g., production of indole-3-acetic acid, siderophore, and 1-aminocyclopropane-1-carboxylate deaminase) and Cd tolerance. Among bacteria, two strains, Klebsiella michiganensis TS8 and Lelliottia jeotgali MR2, presented higher Cd tolerance and showed the best results regarding in vitro growth-promoting traits. In the subsequent pot experiments using soil spiked with 10 mg Cd·kg−1, we investigated the effects of TS8 and MR2 strains on soil Cd phytoremediation when combined with M. floridulus (Lab.). After sixty days of planting M. floridulus (Lab.), we found that TS8 increased plant height by 39.9%, dry weight of leaves by 99.1%, and the total Cd in the rhizosphere soil was reduced by 49.2%. Although MR2 had no significant effects on the efficiency of phytoremediation, it significantly enhanced the Cd translocation from the root to the aboveground tissues (translocation factor > 1). The combination of K. michiganensis TS8 and M. floridulus (Lab.) may be an effective method to remediate Cd-contaminated soils, while the inoculation of L. jeotgali MR2 may be used to enhance the phytoextraction potential of M. floridulus.

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The Effects of Plant Growth-Promoting Bacteria with Biostimulant Features on the Growth of a Local Onion Cultivar and a Commercial Zucchini Variety

Agronomy ◽

10.3390/agronomy11050888 ◽

2021 ◽

Vol 11 (5) ◽

pp. 888

Author(s):

Giorgia Novello ◽

Patrizia Cesaro ◽

Elisa Bona ◽

Nadia Massa ◽

Fabio Gosetti ◽

...

Keyword(s):

Plant Growth ◽

Growth Promotion ◽

Global Market ◽

Plant Growth Promoting Bacteria ◽

Bacterial Strains ◽

Mineral Concentration ◽

Positive Effects ◽

Plant Growth Promoting ◽

Onion Cultivar ◽

Growth Promoting

The reduction of chemical inputs due to fertilizer and pesticide applications is a target shared both by farmers and consumers in order to minimize the side effects for human and environmental health. Among the possible strategies, the use of biostimulants has become increasingly important as demonstrated by the fast growth of their global market and by the increased rate of registration of new products. In this work, we assessed the effects of five bacterial strains (Pseudomonas fluorescens Pf4, P. putida S1Pf1, P. protegens Pf7, P. migulae 8R6, and Pseudomonas sp. 5Vm1K), which were chosen according to their previously reported plant growth promotion traits and their positive effects on fruit/seed nutrient contents, on a local onion cultivar and on zucchini. The possible variations induced by the inoculation with the bacterial strains on the onion nutritional components were also evaluated. Inoculation resulted in significant growth stimulation and improvement of the mineral concentration of the onion bulb, induced particularly by 5Vm1K and S1Pf1, and in different effects on the flowering of the zucchini plants according to the bacterial strain. The present study provides new information regarding the activity of the five plant growth-promoting bacteria (PGPB) strains on onion and zucchini, two plant species rarely considered by the scientific literature despite their economic relevance.

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COLONIZATION of Rubus glaucus BENTH BY AZORHIZOBIUM CAULINODANS ORS571 USIG A FLAVONOIDE NARINGENINA

BISTUA REVISTA DE LA FACULTAD DE CIENCIAS BASICAS ◽

10.24054/01204211.v2.n2.2016.2117 ◽

2016 ◽

Vol 14 (2) ◽

pp. 15

Author(s):

Giovani Orlando Cancino Escalante ◽

S E Cancino ◽

Enrique Quevedo Garcia

Keyword(s):

Bacterial Colonization ◽

Lateral Roots ◽

Plant Growth Promoting Bacteria ◽

Azorhizobium Caulinodans ◽

Intensity Parameters ◽

Plant Growth Promoting ◽

Measuring Frequency ◽

Northwest Region ◽

Azorhizobium Caulinodans Ors571

Root systems of two Andean blackberry materials (thorn and thornless) of Rubus glaucus Benth cultured in vitro in the presence of five treatments (four flavonoids and one control) were inoculated with Azorhizobium caulinodans ORS571 (pXLGD4) (a strain carrying the lacZ reporter gene which facilitated the detection of bacterial colonization). Evaluation of colonization effectiveness for each treatment was done by means of application of experimental design measuring frequency and intensity parameters. Statistical analysis showed differences at comparing flavonoids vs. control and the overall higher effectiveness of the flavonoid naringenin. Observation of colonization was made by light and electron microscope confirming internal colonization of Andean blackberry roots by A. caulinodans. This is the first work demonstrating root colonization of R.glaucus by azorhizobia and therefore settling the basis for future investigations and scientific applications related to interaction with plant growth-promoting bacteria under the effect of flavonoids, along with possible implications of common benefit for non-legume crops in the northwest region of Colombia. Key Words: Azorhizobium caulinodans ORS571, Andean blackberry, flavonoids, LacZ, lateral roots, naringenin.

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Growth response of wheat cultivars to bacterial inoculation in calcareous soil

Plant Soil and Environment ◽

10.17221/75/2010-pse ◽

2010 ◽

Vol 56 (No. 12) ◽

pp. 570-573 ◽

Cited By ~ 14

Author(s):

D. Egamberdieva

Keyword(s):

Plant Growth ◽

Calcareous Soil ◽

Dry Weight ◽

Plant Growth Promoting Bacteria ◽

Wheat Cultivars ◽

Bacterial Strains ◽

Bacterial Inoculation ◽

Plant Growth Promoting ◽

Growth Promoting ◽

Selection Of

In this study the plant growth-promoting bacteria were analysed for their growth-stimulating effects on two wheat cultivars. The investigations were carried out in pot experiments using calcareous soil. The results showed that bacterial strains Pseudomonas spp. NUU1 and P. fluorescens NUU2 were able to colonize the rhizosphere of both wheat cultivars. Their plant growth-stimulating abilities were affected by wheat cultivars. The bacterial strains Pseudomonas sp. NUU1 and P. fluorescens NUU2 significantly stimulated the shoot and root length and dry weight of wheat cv. Turon, whereas cv. Residence was less affected by bacterial inoculation. The results of our study suggest that inoculation of wheat with Pseudomonas strains can improve plant growth in calcareous soil and it depends upon wheat cultivars. Prior to a selection of good bacterial inoculants, it is recommended to select cultivars that benefit from association with these bacteria.

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