scholarly journals Silica particles trigger the production of exopolysaccharides in harsh environment plant growth-promoting rhizobacteria and increase their ability to enhance drought tolerance

2020 ◽  
Author(s):  
Anastasiia Fetsiukh ◽  
Julian Conrad ◽  
Jonas Bergquist ◽  
Fantaye Ayele ◽  
Salme Timmusk
Keyword(s):  
Plant Growth ◽  
Osmotic Pressure ◽  
Plant Biomass ◽  
Plant Growth Promoting Rhizobacteria ◽  
Silica Particles ◽  
Natural Soil ◽  
Plant Responses ◽  
Growth Environment ◽  
Plant Growth Promoting ◽  
Growth Promoting

ABSTRACTIn coming decades drought is expected to expand globally owing to increased evaporation and reduced rainfall. In order to reduce the vulnerability of agricultural systems we need to understand the crop plant growth environment. Understanding, predicting and controlling the rhizosphere has potential to harness plant microbe interactions, improve plant responses to environmental stress and mitigate effects of climate change. Our plant growth-promoting rhizobacteria (PGPR) are isolated from the natural laboratory ‘Evolution Canyon’ Israel (EC). The endophytic rhizobacteria from the wild progenitors of cereals have been co-habituated with their hosts for long periods of time. The study revealed that silica particles (SN) triggered the PGPR production of exopolysaccharides (EPS) containing D-glucuronate (D-GA). This leads to increased plant biomass accumulation in drought-stressed growth environments. The PGPR increased EPS content increases the water holding capacity (WHC) and osmotic pressure of the biofilm matrix. Light- and electron-microscopic studies show that in the presence of SN particles, bacterial morphology is changed, indicating that SNs are associated with significant reprogramming in bacteria.The results here show that the production of EPS containing D-GA is induced by SN treatment. The findings encourage formulation of cells considering microencapsulation with materials that ensure higher WHC and hyperosmolarity under field conditions. Our results illustrate the importance of considering natural soil nanoparticles in the application of PGPR. Osmotic pressure involvement of holobiont cohabitation is discussed.

scholarly journals Silica Particles Trigger the Exopolysaccharide Production of Harsh Environment Isolates of Growth-Promoting Rhizobacteria and Increase Their Ability to Enhance Wheat Biomass in Drought-Stressed Soils

2021 ◽  
Vol 22 (12) ◽  
pp. 6201
Author(s):  
Anastasiia Fetsiukh ◽  
Julian Conrad ◽  
Jonas Bergquist ◽  
Salme Timmusk
Keyword(s):  
Osmotic Pressure ◽  
Large Scale ◽  
Plant Biomass ◽  
Plant Growth Promoting Rhizobacteria ◽  
Silica Particles ◽  
Electron Microscopic ◽  
Bacterial Morphology ◽  
Microscopic Studies ◽  
Plant Growth Promoting ◽  
Growth Promoting

In coming decades, drought is expected to expand globally owing to increased evaporation and reduced rainfall. Understanding, predicting, and controlling crop plants’ rhizosphere has the potential to manipulate its responses to environmental stress. Our plant growth-promoting rhizobacteria (PGPR) are isolated from a natural laboratory, ‘The Evolution Canyon’, Israel, (EC), from the wild progenitors of cereals, where they have been co-habituating with their hosts for long periods of time. The study revealed that commercial TM50 silica particles (SN) triggered the PGPR production of exopolysaccharides (EPS) containing D-glucuronate (D-GA). The increased EPS content increased the PGPR water-holding capacity (WHC) and osmotic pressure of the biofilm matrix, which led to enhanced plant biomass in drought-stressed growth environments. Light- and cryo-electron- microscopic studies showed that, in the presence of silica (SN) particles, bacterial morphology is changed, indicating that SNs are associated with significant reprogramming in bacteria. The findings encourage the development of large-scale methods for isolate formulation with natural silicas that ensure higher WHC and hyperosmolarity under field conditions. Osmotic pressure involvement of holobiont cohabitation is also discussed.

scholarly journals Impact of Plant Growth-Promoting Rhizobacteria Inoculation and Grafting on Tolerance of Tomato to Combined Water and Nutrient Stress Assessed via Metabolomics Analysis

2021 ◽  
Vol 12 ◽  
Author(s):  
Panagiotis Kalozoumis ◽  
Dimitrios Savvas ◽  
Konstantinos Aliferis ◽  
Georgia Ntatsi ◽  
George Marakis ◽  
...  
Keyword(s):  
Plant Growth ◽  
Plant Biomass ◽  
Plant Growth Promoting Rhizobacteria ◽  
Combined Stress ◽  
Nitrogen And Phosphorus ◽  
Screening Process ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
As Stress ◽  
Metabolomics Analysis

In the current study, inoculation with plant growth-promoting rhizobacteria (PGPR) and grafting were tested as possible cultural practices that may enhance resilience of tomato to stress induced by combined water and nutrient shortage. The roots of tomato grown on perlite were either inoculated or not with PGPR, applying four different treatments. These were PGPR-T1, a mix of two Enterobacter sp. strains (C1.2 and C1.5); PGPR-T2, Paenibacillus sp. strain DN1.2; PGPR-T3, Enterobacter mori strain C3.1; and PGPR-T4, Lelliottia sp. strain D2.4. PGPR-treated plants were either self-grafted or grafted onto Solanum lycopersicum cv. M82 and received either full or 50% of their standard water, nitrogen, and phosphorus needs. The vegetative biomass of plants subjected to PGPR-T1 was not reduced when plants were cultivated under combined stress, while it was reduced by stress to the rest of the PGPR treatments. However, PGPR-T3 increased considerably plant biomass of non-stressed tomato plants than did all other treatments. PGPR application had no impact on fruit biomass, while grafting onto ’M82’ increased fruit production than did self-grafting. Metabolomics analysis in tomato leaves revealed that combined stress affects several metabolites, most of them already described as stress-related, including trehalose, myo-inositol, and monopalmitin. PGPR inoculation with E. mori strain C3.1 affected metabolites, which are important for plant/microbe symbiosis (myo-inositol and monopalmitin). The rootstock M82 did not affect many metabolites in plant leaves, but it clearly decreased the levels of malate and D-fructose and imposed an accumulation of oleic acid. In conclusion, PGPR are capable of increasing tomato tolerance to combined stress. However, further research is required to evaluate more strains and refine protocols for their application. Metabolites that were discovered as biomarkers could be used to accelerate the screening process for traits such as stress tolerance to abiotic and/or abiotic stresses. Finally, ‘M82’ is a suitable rootstock for tomato, as it is capable of increasing fruit biomass production.

scholarly journals Microarray Analysis of the Gene Expression Profile Induced by the Endophytic Plant Growth-Promoting Rhizobacteria, Pseudomonas fluorescens FPT9601-T5 in Arabidopsis

2005 ◽  
Vol 18 (5) ◽  
pp. 385-396 ◽  
Author(s):  
Yanqing Wang ◽  
Yumiko Ohara ◽  
Hitoshi Nakayashiki ◽  
Yukio Tosa ◽  
Shigeyuki Mayama
Keyword(s):  
Plant Growth ◽  
Pseudomonas Syringae ◽  
Microarray Analysis ◽  
Plant Growth Promoting Rhizobacteria ◽  
Plant Responses ◽  
Disease Symptoms ◽  
Global View ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Physiological And Biochemical

Pseudomonasz fluorescens FPT9601-T5 was originally identified as an endophytic plant growth-promoting rhizobacteria (PGPR) on tomato. To perform a molecular dissecttion of physiological and biochemical changes occurring in the host triggered by P. fluorescens FPT9601-T5 colonization, the model plant Arabidopsis was used in this study. Root colonization of Arabidopsis with P. fluorescens FPT9601-T5 promoted plant growth later than three weeks after inoculation and partially suppressed disease symptoms caused by Pseudomonas syringae pv. tomato DC3000, indicating that P. fluorescens FPT9601-T5 acted as a PGPR on Arabidopsis. To obtain a global view on transcript modification during the Arabidopsis-FPT9601-T5 interaction, we performed microarray analysis using Affymetrix Genechip probe arrays representing approximately 22,800 genes. The results showed that 95 and 105 genes were up- or down-regulated, respectively, more than twofold in FPT9601-T5-treated Arabidopsis plants as compared with control plants. Those up-regulated included genes involved in metabolism, signal transduction, and stress response. Noteworthy, upon FPT9601-T5 colonization, putative auxin-regulated genes and nodulin-like genes were up-regulated, and some ethylene-responsive genes were down-regulated. Our results suggest that P.fluorescens FPT9601-T5 triggered plant responses in a manner similar to known PGPR and, at least in some aspects, to rhizobia.

scholarly journals Effects of Plant Growth Promoting Rhizobacteria Microbial Inoculants on the Growth, Rhizosphere Soil Properties, and Bacterial Community of Pinus sylvestris var. mongolica Annual Seedlings

2020 ◽  
Author(s):  
Qian Song ◽  
Xiaoshuang Song ◽  
Xun Deng ◽  
Jiayu Luo ◽  
Junkai Wang ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Plant Growth ◽  
Physicochemical Properties ◽  
Plant Biomass ◽  
Soil Nutrient ◽  
Plant Growth Promoting Rhizobacteria ◽  
Inorganic Phosphorus ◽  
Nutrient Index ◽  
Plant Growth Promoting ◽  
Growth Promoting

Abstract [Objective] Determine the ability of three plant growth promoting rhizobacteria (PGPR) strains (Pseudomonas Mandelli A36, Serratia plymuthica A13 and Pseudomonas koreensis A20) to promote plant growth, evaluate the effect of inoculation with PGPR strains on seedling biomass, root structure, nutrient index, and enzyme activity, and assess the effect of PGPR inoculation on soil nutrient index, enzyme activity, and the soil microecological environment.[Method] The ability of the three PGPR strains to secrete indole-3-acetic acid (IAA), dissolve inorganic phosphorus, and produce siderophore and hydrolase was determined by the medium color change method, pot experiment to determine the effects of three PGPR strains on plant biomass, physicochemical properties, soil physicochemical properties and microbial diversity. [Result] The three PGPR strains had the ability to secrete IAA, solubilize inorganic phosphorus, and produce siderophore, the results of the pot experiment showed that inoculation with PGPR strain had a significant effect on plant biomass, root index, nutrient index and enzyme activity, as well as soil nutrient index, enzyme activity and bacterial diversity. [Conclusion] This study provides basic data references for PGPR strains to improve the soil microecological environment and promote the growth and development of Pinus sylvestris var. Mongolica seedlings.

scholarly journals Influence of Nitrogen Sources and Plant Growth-Promoting Rhizobacteria Inoculation on Growth, Crude Fiber and Nutrient Uptake in Squash (Cucurbita moschata Duchesne ex Poir.) Plants

2016 ◽  
Vol 44 (1) ◽  
pp. 53-59 ◽  
Author(s):  
Alice I. TCHIAZE ◽  
Victor D. TAFFOUO ◽  
Henri FANKEM ◽  
Martin KENNE ◽  
Régis BAZIRAMAKENGA ◽  
...  
Keyword(s):  
Plant Growth ◽  
Nutrient Uptake ◽  
Plant Biomass ◽  
Growth Parameters ◽  
Dry Weight ◽  
Plant Growth Promoting Rhizobacteria ◽  
Crude Fiber ◽  
Cellulose Content ◽  
Plant Growth Promoting ◽  
Growth Promoting

Plant growth promoting rhizobacteria (PGPR, B) have immense potential application in sustainable agriculture as ecofriendly biofertilizers and biopesticides. In this study, the effects of three nitrogen (N) sources (NO3-, NH4+ and NO3NH4) and PGPR on growth, crude fiber and nutrient uptake were investigated in squash plants. Some growth parameters [root dry weight (RDW), shoot dry weight (SDW), total plant dry weight (PDW), number of leaves (NL), shoot length (SL), stem diameter (SD) and number of ramifications (NR)], crude fiber (cellulose content) and nutrient uptake (N, P, K, Ca, Mg, Na, Fe, Cu, Mn and Zn) were determined. Application of NO3-, NH4+ or NO3NH4 singly or in combination with PGPR inoculation led to a significant increase in RDW, SDW, PDW, NL, SL, SD and NR. Na, Cu and Zn contents, on the contrary, decreased in inoculated treated plants while no significant differences were recorded in cellulose contents (CE) of leaves except in plants fed with NO3-. The leaf CE content ranged from 12.58 to 13.67%. The plants supplied with NO3+B, NH4+B and NO3NH4+B showed significantly higher plant biomass and accumulation of N, P, K and Mn concentrations in leaves compared to all other treatments. These results suggest that specific combinations of PGPR with NO3-, NH4+ or NO3NH4 fertilizers can be considered as efficient alternative biofertilizers to improve significantly the squash growth and nutrient uptake.

scholarly journals Improved chromium tolerance of Medicago sativa by plant growth-promoting rhizobacteria (PGPR)

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Nabil Tirry ◽  
Aziza Kouchou ◽  
Bouchra El Omari ◽  
Mohamed Ferioun ◽  
Naïma El Ghachtouli
Keyword(s):  
Plant Growth ◽  
Medicago Sativa ◽  
Contaminated Soils ◽  
Plant Biomass ◽  
Growth Promotion ◽  
Plant Growth Promoting Rhizobacteria ◽  
Biochemical Tests ◽  
Pgp Traits ◽  
Plant Growth Promoting ◽  
Growth Promoting

Abstract Background Soil pollution by heavy metals increases the bioavailability of metals like hexavalent chromium (Cr (VI)), subsequently limiting plant growth and reducing the efficiency of phytoremediation. Plant growth-promoting rhizobacteria (PGPR) have substantial potential to enhance plant growth as well as plant tolerance to metal stress. The aim of this research was to investigate Cr (VI) phytoremediation enhancement by PGPR. Results The results showed that the 27 rhizobacterial isolates studied were confirmed as Cr (VI)-resistant PGPR, by using classical biochemical tests (phosphate solubilization, nitrogen fixation, indole acetic acid, exopolysaccharides, hydrogen cyanide, siderophores, ammonia, cellulase, pectinase, and chitinase production) and showed variable levels of Cr (VI) resistance (300–600 mg/L). The best four selected Cr (VI)-resistant PGPR (NT15, NT19, NT20, and NT27) retained most of the PGP traits in the presence of 100–200 mg/L concentrations of Cr (VI). The inoculation of Medicago sativa with any of these four isolates improved the shoot and root dry weight. The NT27 isolate identified using 16S rDNA gene sequence analyses as a strain of Pseudomonas sp. was most effective in terms of plant growth promotion and stress level decrease. It increased shoot and root dry weights of M. sativa by 97.6 and 95.4%, respectively, in the presence of Cr (VI) when compared to non-inoculated control plants. It also greatly increased chlorophyll content and decreased the levels of stress markers, malondialdehyde, hydrogen peroxide, and proline. The results of the effect of Pseudomonas sp. on Cr content and bioaccumulation factor (BAF) of the shoots and roots of M. sativa plants showed the increase of plant biomass concomitantly with the increase of Cr root concentration in inoculated plants. This would lead to a higher potential of Cr (VI) phytostabilization. Conclusions This study demonstrates that the association M. sativa-Pseudomonas sp. may be an efficient biological system for the bioremediation of Cr (VI)-contaminated soils.

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