scholarly journals Evaluation of some biophysical characteristics of five silicate solubilizing bacteria isolated from different ecosystems

2020 ◽  
Vol 17 (4) ◽  
pp. 775-784
Author(s):  
Tran Vo Hai Duong ◽  
Nguyen Khoi Nghia
Keyword(s):  
Growth Promotion ◽  
High Capacity ◽  
Soil Extract ◽  
Growth And Yield ◽  
Silicate Mineral ◽  
Insoluble Phosphate ◽  
Extract Medium ◽  
Key Microorganisms ◽  
Solubilizing Capacity ◽  
Indole 3 Acetic Acid

Silicate solubilizing bacteria (SSB) are key microorganisms to solubilize silicate minerals in the soil. Silicon helps to increase the growth and yield of plants and to enhance the environmental stress tolerance capability of plants. The aim of this study was to evaluate the effect of several factors like pH, salinity, and temperature on silicate solubilizing capacity of five selected SSB. Moreover, phosphorus solubilizing, nitrogen-fixing and indole-3-acetic acid (IAA) synthesizing capacity of these five bacteria were also tested. Liquid soil extract medium containing 0.25% Mg2O8Si3 was used in this study. Abilities of bacteria in phosphorous solubility, nitrogen fixation, and IAA synthesis were tested in NBRIP, Burk’s and NBRIP containing 100 mg L-1 tryptophan media, respectively. The results of the study indicated that five SSB showed their high capacity in silicate solubilization at pH 7.0, NaCl 0.0% and 35oC. However, at a concentration of NaCl 0.5%, these five SSB still solubilized well silicate mineral. Moreover, they also solubilized effectively three different insoluble phosphate sources of Ca3(PO4)2, AlPO4 and FePO4 with a range varied between 105.8 and 928.7 mg P2O5 L-1, 33.9 and 49.6 mg P2O5 L-1, and 1.94 and 34.1 mg P2O5 L-1, respectively. They also fixed biologically nitrogen with a range from 1.37 to 5.09 mg NH4+ L-1 after 2 incubation days. Finally, they also showed their ability in IAA synthesis with an amount between 4.85 and 51.5 mg IAA L-1. In short, these five SSB in this study not only had the ability in silicate solubilization but also had other functions in plant growth promotion.

scholarly journals Plant Growth Promotion Assessment in Rice Plant Enhanced by Inoculation of Rhizobacteria

2015 ◽  
Vol 4 ◽  
pp. 73-84
Author(s):  
Umesh Prasad Shrivastava
Keyword(s):  
Chlorophyll A ◽  
Growth Promotion ◽  
Soil Extract ◽  
Fresh Weight ◽  
Rice Varieties ◽  
Total Length ◽  
Gusa Reporter Gene ◽  
Extract Medium ◽  
Chlorophyll A Content ◽  
Weight Number

In the search of efficient biofertilizer, nine efficient strains of PGPR were evaluated by inoculation in two different rice varieties, Saryu-52 and Malviya Dhan-36 in the gnotobiotic conditions using two different media FCN-medium and soil extract medium. Agrobacterium sp. strain BN-2A showed better result in respect to other eight isolates in the total length, fresh weight, number of roots and chlorophyll-a content. By the inoculation Agrobacterium sp. strain BN-2A, total length increased in Saryu-52 (22.6%) and in Malviya Dhan-36 (52.1%), fresh weight increased in Saryu-52 (42.4%) and in Malviya Dhan-36 (68.8%) and chlorophyll-a increased in Saryu-52 (76.6%) and in Malviya Dhan-36 (37.1%). Similarly in soil extract medium, inoculation of Agrobacterium sp. strain BN-2A alone showed better result in comparison to mixture of nine strains. To prove that colonization indeed occurs, gusA reporter gene was tagged with the most efficient isolate Agrobacterium sp. strain BN-2A and colonization in the rice root was confirmed by gusA staining and histochemical analysis of gusA staining. Therefore, BN-2A has best potential to be used as biofertilizer.DOI: http://dx.doi.org/10.3126/av.v4i0.12362Academic Voices Vol.4 2014: 73-84

scholarly journals Changes in Volatile Organic Compounds from Salt-Tolerant Trichoderma and the Biochemical Response and Growth Performance in Saline-Stressed Groundnut

2021 ◽  
Vol 13 (23) ◽  
pp. 13226
Author(s):  
Eriyanto Yusnawan ◽  
Abdullah Taufiq ◽  
Andy Wijanarko ◽  
Dwi Ningsih Susilowati ◽  
Raden Heru Praptana ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Growth Stage ◽  
Growth Promotion ◽  
Growth And Yield ◽  
Salt Tolerant ◽  
Volatile Organic ◽  
Growth Promoting ◽  
Indole 3 Acetic Acid ◽  
Trichoderma Isolates

Soil salinity is one of the major obstacles that is limiting the growth and yield of groundnut. This study aims to investigate the effect of growth-promoting fungi, Trichoderma, on groundnut plants that were cultivated in saline conditions. Five different Trichoderma isolates were grown in four different NaCl concentrations. Selected Trichoderma were then applied to the groundnut seeds and their growth and development were monitored during the study. Growth inhibition, volatile organic compounds, chlorophylls, carotenoids, total phenolics and flavonoids, and minerals were assessed between the Trichoderma treatments. Increasing the salt concentration from 0.25–0.75 M decreased the growth of the Trichoderma isolates. The amounts and profiles of the volatile organic compounds from the T. asperellum isolate were significantly different to those in the T. virens isolate. In the vegetative growth stage, increased chlorophyll content was recorded in both the T. asperellum and T. virens-treated groundnut. The leaves that were obtained from the groundnut that was treated with T. virens T.v4 contained significantly higher indole-3-acetic acid (420 µg IAA/g) than the same plants’ roots (113.3 µg IAA/g). Compared to the control groundnut, the T. asperellum T.a8-treated groundnut showed increased phenolics (31%) and flavonoids (43%) and increased shoots and biomass weight at the generative growth stage. This study demonstrates that Trichoderma, with their plant growth promotion ability, could potentially be used to improve the growth of groundnut growing under salinity stress. Importantly, salt-tolerant Trichoderma could be regarded as a beneficial and sustainable way to improve the survival of salt-sensitive crops.

scholarly journals Combined Application of Rhizosphere Bacteria with Endophytic Bacteria Suppresses Root Diseases and Increases Productivity of Black Pepper (Piper nigrum L.)

Agriculture ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 15
Author(s):  
Sy Dinh Nguyen ◽  
Thi Huyen Trang Trinh ◽  
Trung Dzung Tran ◽  
Tinh Van Nguyen ◽  
Hoang Van Chuyen ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Endophytic Bacteria ◽  
Growth Promotion ◽  
Black Pepper ◽  
Rhizosphere Bacteria ◽  
Growth And Yield ◽  
Piper Nigrum ◽  
Bacillus Velezensis ◽  
Root Knot Nematode ◽  
Central Highland

Black pepper (Piper nigrum L.) is one of the most important crops and global demand continues to increase, giving it a high export value. However, black pepper cultivation has been seriously affected by a number of pathogenic diseases. Among them, “quick wilt” caused by Phytophthora sp., “slow decline” caused by Fusarium sp., and root-knot nematode Meloidogyne sp. have a serious negative effect on black pepper growth and productivity. There have been different chemical and biological methods applied to control these diseases, but their effectiveness has been limited. The aim of this research was to evaluate different combinations of rhizosphere bacteria and endophytic bacteria isolated from black pepper farms in the Central Highland of Vietnam for their ability to suppress pathogens and promote black pepper growth and yield. Formula 6, containing the strains Bacillus velezensis KN12, Bacillus amyloliquefaciens DL1, Bacillus velezensis DS29, Bacillus subtilis BH15, Bacillus subtilis V1.21 and Bacillus cereus CS30 exhibited the largest effect against Phytophthora and Fusarium in the soil and in the roots of black pepper. These bio-products also increased chlorophyll a and b contents, which led to a 1.5-fold increase of the photosynthetic intensity than the control formula and a 4.5% increase in the peppercorn yield (3.45 vs. 3.30 tons per hectare for the control). Our results suggest that the application of rhizosphere and endophytic bacteria is a promising method for disease control and growth-promotion of black pepper.

scholarly journals The Distribution of Tryptophan-Dependent Indole-3-Acetic Acid Synthesis Pathways in Bacteria Unraveled by Large-Scale Genomic Analysis

Molecules ◽  
2019 ◽  
Vol 24 (7) ◽  
pp. 1411 ◽  
Author(s):  
Pengfan Zhang ◽  
Tao Jin ◽  
Sunil Kumar Sahu ◽  
Jin Xu ◽  
Qiong Shi ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Large Scale ◽  
Growth Promotion ◽  
Plant Root ◽  
Genomic Analysis ◽  
Acid Synthesis ◽  
Metagenomic Data ◽  
Bacterial Genomes ◽  
Bacterial Phyla ◽  
Indole 3 Acetic Acid

Bacterial indole-3-acetic acid (IAA), an effector molecule in microbial physiology, plays an important role in plant growth-promotion. Here, we comprehensively analyzed about 7282 prokaryotic genomes representing diverse bacterial phyla, combined with root-associated metagenomic data to unravel the distribution of tryptophan-dependent IAA synthesis pathways and to quantify the IAA synthesis-related genes in the plant root environments. We found that 82.2% of the analyzed bacterial genomes were potentially capable of synthesizing IAA from tryptophan (Trp) or intermediates. Interestingly, several phylogenetically diverse bacteria showed a preferential tendency to utilize different pathways and tryptamine and indole-3-pyruvate pathways are most prevalent in bacteria. About 45.3% of the studied genomes displayed multiple coexisting pathways, constituting complex IAA synthesis systems. Furthermore, root-associated metagenomic analyses revealed that rhizobacteria mainly synthesize IAA via indole-3-acetamide (IAM) and tryptamine (TMP) pathways and might possess stronger IAA synthesis abilities than bacteria colonizing other environments. The obtained results refurbished our understanding of bacterial IAA synthesis pathways and provided a faster and less labor-intensive alternative to physiological screening based on genome collections. The better understanding of IAA synthesis among bacterial communities could maximize the utilization of bacterial IAA to augment the crop growth and physiological function.

Rhizobium leguminosarum as a plant growth-promoting rhizobacterium: direct growth promotion of canola and lettuce

1996 ◽  
Vol 42 (3) ◽  
pp. 279-283 ◽  
Author(s):  
T. C. Noel ◽  
C. Sheng ◽  
C. K. Yost ◽  
R. P. Pharis ◽  
M. F. Hynes
Keyword(s):  
Acetic Acid ◽  
Plant Growth ◽  
Rhizobium Leguminosarum ◽  
Growth Promotion ◽  
Plant Growth Promoting Rhizobacteria ◽  
Plant Growth Promoting ◽  
Direct Growth ◽  
Early Seedling ◽  
Growth Promoting ◽  
Indole 3 Acetic Acid

Early seedling root growth of the nonlegumes canola (Brassica campestris cv. Tobin, Brassica napus cv. Westar) and lettuce (Lactuca saliva cv. Grand Rapids) was significantly promoted by inoculation of seeds with certain strains of Rhizobium leguminosarum, including nitrogen- and nonnitrogen-fixing derivatives under gnotobiotic conditions. The growfh-promotive effect appears to be direct, with possible involvement of the plant growth regulators indole-3-acetic acid and cytokinin. Auxotrophic Rhizobium mutants requiring tryptophan or adenosine (precursors for indole-3-acetic acid and cytokinin synthesis, respectively) did not promote growth to the extent of the parent strain. The findings of this study demonstrate a new facet of the Rhizobium–plant relationship and that Rhizobium leguminosarum can be considered a plant growth-promoting rhizobacterium (PGPR).Key words: Rhizobium, plant growth-promoting rhizobacteria, PGPR, indole-3-acetic acid, cytokinin, roots, auxotrophic mutants.

scholarly journals Quorum Sensing and Indole-3-Acetic Acid Degradation Play a Role in Colonization and Plant Growth Promotion of Arabidopsis thaliana by Burkholderia phytofirmans PsJN

2013 ◽  
Vol 26 (5) ◽  
pp. 546-553 ◽  
Author(s):  
Ana Zúñiga ◽  
María Josefina Poupin ◽  
Raúl Donoso ◽  
Thomas Ledger ◽  
Nicolás Guiliani ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Acetic Acid ◽  
Quorum Sensing ◽  
Plant Growth ◽  
Growth Promotion ◽  
Auxin Signaling ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Indole 3 Acetic Acid ◽  
Burkholderia Phytofirmans Psjn

Although not fully understood, molecular communication in the rhizosphere plays an important role regulating traits involved in plant–bacteria association. Burkholderia phytofirmans PsJN is a well-known plant-growth-promoting bacterium, which establishes rhizospheric and endophytic colonization in different plants. A competent colonization is essential for plant-growth-promoting effects produced by bacteria. Using appropriate mutant strains of B. phytofirmans, we obtained evidence for the importance of N-acyl homoserine lactone-mediated (quorum sensing) cell-to-cell communication in efficient colonization of Arabidopsis thaliana plants and the establishment of a beneficial interaction. We also observed that bacterial degradation of the auxin indole-3-acetic acid (IAA) plays a key role in plant-growth-promoting traits and is necessary for efficient rhizosphere colonization. Wildtype B. phytofirmans but not the iacC mutant in IAA mineralization is able to restore promotion effects in roots of A. thaliana in the presence of exogenously added IAA, indicating the importance of this trait for promoting primary root length. Using a transgenic A. thaliana line with suppressed auxin signaling (miR393) and analyzing the expression of auxin receptors in wild-type inoculated plants, we provide evidence that auxin signaling in plants is necessary for the growth promotion effects produced by B. phytofirmans. The interplay between ethylene and auxin signaling was also confirmed by the response of the plant to a 1-aminocyclopropane-1-carboxylate deaminase bacterial mutant strain.

scholarly journals First Report of Phytophthora Root Rot of Sugar Beet, Caused by Phytophthora cryptogea, in Greece

Plant Disease ◽  
2000 ◽  
Vol 84 (5) ◽  
pp. 593-593 ◽  
Author(s):  
G. S. Karaoglanidis ◽  
D. A. Karadimos ◽  
K. Klonari
Keyword(s):  
Sugar Beet ◽  
Root Rot ◽  
Soil Extract ◽  
American Phytopathological Society ◽  
Phytophthora Root Rot ◽  
Phytophthora Cryptogea ◽  
First Report ◽  
Solid Media ◽  
Necrotic Spots ◽  
Extract Medium

A severe rot of sugar beet roots was observed in the Amyndeon area of Greece during summer 1998. Infected plants initially showed a temporary wilt, which became permanent, and finally died. Slightly diseased roots showed necrotic spots toward the base, whereas more heavily diseased roots showed a more extensive wet rot that extended upward. Feeder roots also were infected and reduced in number because of decay. Rotted tissue was brown with a distinguishing black margin. In most of the isolations, carried out on potato dextrose agar (PDA), the pathogen obtained was identified as Phytophthora cryptogea Pethybr. & Lafferty Mycelium consisted of fairly uniform, fine hyphae that showed a slightly floral growth pattern. In autoclaved soil-extract medium, chains or clusters of hyphal swellings (average 12 µm diameter) formed. Sporangia were not produced on solid media but were abundant in soil-extract medium. Sporangia were oval to obpyriform in shape, nonpapillate with rounded bases, and varied in size (39 to 80 × 24 to 40 µm). Oospores were plerotic, thick-walled, and averaged 25 µm in diameter. The isolated pathogen, cultured on PDA, could not grow at all at 36°C. The closely related species P. drechsleri Tucker has been reported to cause similar root rot symptoms on sugar beet (3). However, P. drechsleri grows well at 36°C, while P. cryptogea cannot grow at this temperature; this is the major distinguishing feature that separates the two species (1). To test the pathogenicity of the organism, surface-sterilized sugar beet roots (cv. Rizor) were inoculated with 5-mm-diameter PDA plugs containing actively growing mycelium. Sterile PDA plugs were used to inoculate control sugar beet roots. Inoculated roots were kept at 27°C in the dark for 10 days. Extensive decay of inoculated roots developed, similar to decay observed in the field, whereas control roots showed no decay. P. cryptogea was reisolated from rotted tissues. This pathogen has been recognized previously as a cause of root rot of sugar beet in Japan (1) and Wyoming (2). This is the first report of Phytophthora root rot of sugar beet in Greece. References: (1) D. C. Erwin and O. K. Ribeiro. 1996. Phytophthora Diseases Worldwide. The American Phytopathological Society, St. Paul, MN. (2) P. C. Vincelli et. al. Plant Dis. 74:614, 1990. (3) E. D. Whitnew and J. E. Duffus, eds. 1986. Compendium of Beet Diseases and Insects. The American Phytopathological Society, St. Paul, MN.

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