External and internal root colonization of lodgepole pine seedlings by two growth-promoting Bacillus strains originated from different root microsites

1995 ◽  
Vol 41 (8) ◽  
pp. 707-713 ◽  
Author(s):  
M. Shishido ◽  
B. M. Loeb ◽  
C. P. Chanway
Keyword(s):  
Root Colonization ◽  
Lodgepole Pine ◽  
Substrate Utilization ◽  
Root Tissue ◽  
Pine Seedlings ◽  
Growth Promoting ◽  
Root Tissues ◽  
Bacillus Strains ◽  
Fresh Root

Root colonization and in vitro carbon substrate utilization by two seedling growth-promoting Bacillus strains that originated from different root microsites were studied in greenhouse and growth chamber experiments. Strain L6, identified as Bacillus polymyxa, was previously isolated from rhizosphere soil containing roots of pasture plants, and Pw-2, tentatively identified also as B. polymyxa, was isolated from within surface-sterilized lodgepole pine (Pinus contorta var. latifolia (Dougl.) Engelm.) roots. Rifamycin-resistant strains derived spontaneously from wild-type strains L6 and Pw-2, designated strain L6-16R and Pw-2R, respectively, were used to monitor lodgepole pine root colonization in a closed tube assay system. Three-week-old pine seedlings were inoculated with 105 colony-forming units (cfu) of strain Pw-2R or 106 cfu of strain L6-16R, and external and internal root colonization was assessed 2 and 4 weeks later. Strains L6-16R and Pw-2R were both recovered from pine rhizosphere samples with > 5 × 107 cfu/g fresh root tissue 2 weeks after inoculation, but neither strain was detected in the root interior. When root colonization was assessed 4 weeks after inoculation, the rhizosphere populations of both strains had declined slightly to between 5 × 106 and 5 × 107 cfu/g fresh root tissue, but strain Pw-2R was also detected within root tissues with 105 cfu/g fresh root tissue. Lateral root formation was abundant 4 weeks after inoculation and may have facilitated colonization of internal root tissues by strain Pw-2R. Both strains possessed pectolytic activity, although differences between the strains were detected in in vitro substrate utilization capabilities using BIOLOG assays. These differences may be related to their abilities to colonize internal root tissues. On the basis of our results, we hypothesize that internal root colonization by Bacillus strains is not a random event and that root-endophytic Bacillus strains possess specific physiological and (or) biochemical characteristics that facilitate colonization of internal root tissues.Key words: Bacillus, PGPR, rhizosphere, endophytes, colonization.

scholarly journals A prospectus of plant growth promoting endophytic bacterium from orchid (Vanda cristata)

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Sujit Shah ◽  
Krishna Chand ◽  
Bhagwan Rekadwad ◽  
Yogesh S. Shouche ◽  
Jyotsna Sharma ◽  
...  
Keyword(s):  
Plant Growth ◽  
Root Colonization ◽  
Endophytic Bacterium ◽  
Epifluorescence Microscopy ◽  
In Vitro Cultivation ◽  
Rrna Gene ◽  
Bacillus Spp ◽  
Plant Growth Promoting ◽  
Growth Promoting

Abstract Background A plant growth-promoting endophytic bacterium PVL1 isolated from the leaf of Vanda cristata has the ability to colonize with roots of plants and protect the plant. PVL1 was isolated using laboratory synthetic media. 16S rRNA gene sequencing method has been employed for identification before and after root colonization ability. Results Original isolated and remunerated strain from colonized roots were identified as Bacillus spp. as per EzBiocloud database. The presence of bacteria in the root section of the plantlet was confirmed through Epifluorescence microscopy of colonized roots. The in-vitro plantlet colonized by PVL1 as well as DLMB attained higher growth than the control. PVL1 capable of producing plant beneficial phytohormone under in vitro cultivation. HPLC and GC-MS analysis suggest that colonized plants contain Indole Acetic Acid (IAA). The methanol extract of Bacillus spp., contains 0.015 μg in 1 μl concentration of IAA. PVL1 has the ability to produce antimicrobial compounds such as ethyl iso-allocholate, which exhibits immune restoring property. One-way ANOVA shows that results were statistically significant at P ≤ 0.05 level. Conclusions Hence, it has been concluded that Bacillus spp. PVL1 can promote plant growth through secretion of IAA during root colonization and ethyl iso-allocholate to protect plants from foreign infections. Thus, this study supports to support Koch’s postulates of bacteria establishment.

Evaluation of the phytotoxicity of 2,4-diacetylphloroglucinol and Pseudomonas brassicacearum Q8r1-96 on different wheat cultivars

2021 ◽  
Author(s):  
Mingming Yang ◽  
Linda S Thomashow ◽  
David M Weller
Keyword(s):  
Seed Germination ◽  
Pacific Northwest ◽  
Root Colonization ◽  
The United States ◽  
Wheat Cultivars ◽  
The Pacific ◽  
Root Necrosis ◽  
Growth Promoting ◽  
Pseudomonas Brassicacearum

Pseudomonas brassicacearum Q8r1-96 and other 2,4-diacetylphloroglucinol (DAPG)-producing pseudomonads of the Pseudomonas fluorescens complex possess both biocontrol and growth-promoting properties and play an important role in suppression of take-all of wheat in the Pacific Northwest (PNW) of the United States. However, P. brassicacearum can also reduce seed germination and cause root necrosis on some wheat cultivars. We evaluated the effect of Q8r1-96 and DAPG on the germination of 69 wheat cultivars that have been or currently are grown in the PNW. Cultivars varied widely in their ability to tolerate P. brassicacearum or DAPG. The frequency of germination of the cultivars ranged from 0 to 0.87 and from 0.47 to 0.90 when treated with Q8r1-96 and DAPG, respectively. There was a significant positive correlation between the frequency of germination of cultivars treated with Q8r1-96 in assays conducted in vitro and in the greenhouse. The correlation was greater for spring than for winter cultivars. In contrast, the effect of Q8r1-96 on seed germination was not correlated with that of DAPG alone, suggesting that DAPG is not the only factor responsible for the phytotoxicity of Q8r1-96. Three wheat cultivars with the greatest tolerance and three cultivars with the least tolerance to Q8r1-96 were tested for their ability to support root colonization by strain Q8r1-96. Cultivars with the greatest tolerance supported significantly greater populations of strain Q8r1-96 than those with the least tolerance to the bacteria. Our results show that wheat cultivars differ widely in their interaction with P. brassicacearum and the biocontrol antibiotic DAPG.

Recovery of a rhizosphere-colonizing GEM from inside wheat roots

1999 ◽  
Vol 45 (7) ◽  
pp. 612-615 ◽  
Author(s):  
James D Nairn ◽  
Christopher P Chanway
Keyword(s):  
Rhizosphere Soil ◽  
Genetically Engineered ◽  
Root Tissue ◽  
Marker Genes ◽  
Wheat Roots ◽  
Genetically Engineered Microorganisms ◽  
Population Sizes ◽  
Genetically Engineered Microorganism ◽  
Root Tissues ◽  
Fresh Root

Pseudomonas chloroaphis 3732 RN-L11 is a genetically modified bacterial strain that contains the lacZY marker genes in its chromosome. This strain is known to be a vigorous colonizer of plant roots and rhizosphere soil, and has been used as a model to evaluate survival and persistence of field-released genetically engineered microorganisms (GEMs). However, the possibility that strain 3732 RN-L11 may also colonize internal plant tissues has not previously been investigated. Using spring wheat as a model system, we studied the ability of strain 3732 RN-L11 to colonize external and internal root tissues after seed inoculation. Strain 3732 RN-L11 was recovered from rhizosphere soil of 28-, 42-, and 56-day-old seedlings with mean population sizes of 3.3 × 105, 7.5 × 104, and 2.2 × 105CFU·g-1fresh root tissue, respectively. In addition, this strain was consistently recovered from surface-sterilized root tissues of 28- to 56-day-old seedlings with mean population sizes of 1.0 × 102to 6.2 × 103CFU·g-1fresh root tissue. Our results indicate that evaluation of plant-associated GEM populations after field release should include all possible colonization niches, including internal plant tissues.Key words: genetically engineered microorganism, rhizosphere, endophyte.

In Vitro and In Vivo Characterization of Plant Growth Promoting Bacillus Strains Isolated from Extreme Environments of Eastern Algeria

2013 ◽  
Vol 172 (4) ◽  
pp. 1735-1746 ◽  
Author(s):  
Asma Ait-Kaki ◽  
Noreddine Kacem-Chaouche ◽  
Marc Ongena ◽  
Mounira Kara-Ali ◽  
Laid Dehimat ◽  
...  
Keyword(s):  
Plant Growth ◽  
Extreme Environments ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Eastern Algeria ◽  
In Vivo Characterization ◽  
Bacillus Strains

scholarly journals Root colonization and interaction among growth promoting rhizobacteria isolates and eucalypts species

2009 ◽  
Vol 33 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Reginaldo Gonçalves Mafia ◽  
Acelino Couto Alfenas ◽  
Eraclides Maria Ferreira ◽  
Daniel Henrique Breda Binoti ◽  
Gizella Machado Ventura Mafia ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Stenotrophomonas Maltophilia ◽  
Root Colonization ◽  
Growth Promotion ◽  
Eucalyptus Species ◽  
Growth Promoter ◽  
Pseudomonas Sp ◽  
Potential Growth ◽  
Growth Promoting

This work aimed to evaluate root colonization and interaction among isolates of rhizobacteria and eucalypt species. The method used to evaluate "in vitro" root colonization was able to indicate if the effect was benefic or deleterious allowing to pre-select isolates as potential growth promoter. There was interaction among isolates of rhizobacteria and Eucalyptus species for seed germinating and seedling growth. MF2 (Pseudomonas sp.) was the best rhizobacteria isolate for growth promotion of E. cloeziana e E. grandis. S1 (Bacillus subtilis) was the most effective for E. globulus, and Ca (Pseudomonas fulva), MF2 (Pseudomonas sp.), CIIb (Stenotrophomonas maltophilia) and S2 (B. subtilis) were the most promising isolates for the E. urophylla.

scholarly journals Genome-guided insights of tropical Bacillus strains efficient in maize growth promotion

2020 ◽  
Vol 96 (9) ◽  
Author(s):  
Camila Cristina Vieira Velloso ◽  
Christiane Abreu de Oliveira ◽  
Eliane Aparecida Gomes ◽  
Ubiraci Gomes de Paula Lana ◽  
Chainheny Gomes de Carvalho ◽  
...  
Keyword(s):  
Plant Growth ◽  
Growth Promotion ◽  
Dry Weight ◽  
Phenotypic Characterization ◽  
Plant Growth Promoting Bacteria ◽  
Maize Genotypes ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Bacillus Strains

ABSTRACT Plant growth promoting bacteria (PGPB) are an efficient and sustainable alternative to mitigate biotic and abiotic stresses in maize. This work aimed to sequence the genome of two Bacillus strains (B116 and B119) and to evaluate their plant growth-promoting (PGP) potential in vitro and their capacity to trigger specific responses in different maize genotypes. Analysis of the genomic sequences revealed the presence of genes related to PGP activities. Both strains were able to produce biofilm and exopolysaccharides, and solubilize phosphate. The strain B119 produced higher amounts of IAA-like molecules and phytase, whereas B116 was capable to produce more acid phosphatase. Maize seedlings inoculated with either strains were submitted to polyethylene glycol-induced osmotic stress and showed an increase of thicker roots, which resulted in a higher root dry weight. The inoculation also increased the total dry weight and modified the root morphology of 16 out of 21 maize genotypes, indicating that the bacteria triggered specific responses depending on plant genotype background. Maize root remodeling was related to growth promotion mechanisms found in genomic prediction and confirmed by in vitro analysis. Overall, the genomic and phenotypic characterization brought new insights to the mechanisms of PGP in tropical Bacillus.

scholarly journals Evaluation of Bacillus Strains for Plant Growth Promotion and Predictability of Efficacy by In Vitro Physiological Traits

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Rufus J. Akinrinlola ◽  
Gary Y. Yuen ◽  
Rhae A. Drijber ◽  
Anthony O. Adesemoye
Keyword(s):  
Plant Growth ◽  
Bacillus Megaterium ◽  
Growth Promotion ◽  
High Growth ◽  
Physiological Traits ◽  
Nonsterile Soil ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Bacillus Strains

Bacilli are commonly used as plant growth-promoting agents but can be limited in effectiveness to certain crop and soil environments. The objectives of this study were to (1) identify Bacillus strains that can be consistent in promoting the growth of corn, wheat, and soybean and (2) determine whether physiological traits expressed in vitro can be predictive of growth promotion efficacy/consistency and be used for selecting effective strains. Twelve Bacillus strains isolated from wheat rhizospheres were evaluated in greenhouse pot tests with nonsterile soil for their effects on the growth of corn, soybean, and wheat. The strains also were assessed in vitro for multiple physiological traits. All 12 strains increased corn growth significantly compared to the controls. The four most efficacious strains on corn—Bacillus megaterium R181, B. safensis R173, B. simplex R180, and Paenibacillus graminis R200—also increased the growth of soybean and wheat. No set of traits was a predictor of growth promotion efficacy. The number of traits expressed by a strain also was not an indicator of efficacy as strain R200 that was positive for only one trait showed high growth promotion efficacy. Effective strains can be identified through pot tests on multiple crop plants, but in vitro physiological assays are unreliable for strain selection.

scholarly journals Biochemical Responses of Shoot and Root Tissues of Sainfoin (Onobrychis viciifolia Scop.) to NaCl-Salt Stress Under İn Vitro Conditions

2019 ◽  
Vol 7 (1) ◽  
pp. 110
Author(s):  
Ramazan Beyaz
Keyword(s):  
Antioxidant Enzymes ◽  
Salt Stress ◽  
Root Tissue ◽  
Ms Medium ◽  
Forage Crops ◽  
Sod Activity ◽  
Onobrychis Viciifolia ◽  
Biochemical Responses ◽  
Root Tissues

Sainfoin (Fabaceae) is one of the most critical animal forage crops. However, the tolerance of sainfoin is low against to salinity. This study aims to investigate biochemical responses of the shoot and root tissue of sainfoin seedlings to moderate salt stress under in vitro conditions. For this aim, the seed of sainfoin were sown MS medium containing 100 mM NaCl. Antioxidant enzymes (CAT, SOD, APX, and GR), proline and malondialdehyde (MDA) contents were measured in shoot and root tissue of 35-day-old seedlings of sainfoin. A significantly higher constitutive catalase (CAT) and superoxide dismutase (SOD) activity was observed in shoot tissues when compared to root tissues. Overall, salt stress caused significant more enhancement in the activity of antioxidant enzymes (CAT, SOD, APX, and GR) in shoot tissues than root tissue. On the other hand, among the antioxidant enzymes, SOD seems to be more active in both tissues of sainfoin. Interestingly, the activity of GR reduced in both tissue under salt stress. The content of proline and MDA has been increased under salt stress and this increase has been more in the root tissue. This study has revealed biochemical responses to salt stress in different organs of sainfoin.

Biochemical responses of sainfoin shoot and root tissues to drought stress in In vitro Culture

2019 ◽  
Author(s):  
Ramazan Beyaz
Keyword(s):  
Drought Stress ◽  
Critical Role ◽  
Root Tissue ◽  
Antioxidant Enzyme Activities ◽  
Chlorophyll Contents ◽  
Biochemical Responses ◽  
Shoot Tissue ◽  
Mda Content ◽  
Root Tissues

This study was conducted to investigate the biochemical responses of the shoot and root tissues of sainfoin to drought stress under in vitro conditions. Seeds of sainfoin were cultured on MS (Murashige and Skoog) medium with addition of concentrations of PEG-6000 (50, 100, and 150 g/l). Biochemical analyzes (CAT, SOD, GR, and APX enzyme activity; proline, malondialdehyde (MDA) and chlorophyll contents) were carried out on the 35-day-old seedlings. The principal results of the study were that CAT and SOD antioxidant enzymes seemed to play a critical role in oxidative stress in both tissues of sainfoin seedlings. On the other hand, a significant decrease in GR activity and no change in APX activity detected in both tissues under stress. The contents of proline and MDA increased in both tissues while the chlorophyll contents decreased in the shoot tissue. Antioxidant enzyme activities seemed to be more active in the root tissue than the shoot tissue. Accumulation of proline was higher in the root tissue, while the MDA content was higher in the shoot tissue of the seedlings.

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