Plant growth promoting and its mechanism of hydrogen-oxidizing bacteria isolated from <italic>Medicago sativa</italic> rhizosphere

2010 ◽  
Vol 55 (17) ◽  
pp. 1690-1695
Author(s):  
WeiWei WANG ◽  
BenTao XIONG ◽  
Bo FU ◽  
XingDu CHEN ◽  
Ming TANG
Keyword(s):  
Plant Growth ◽  
Medicago Sativa ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Hydrogen Oxidizing Bacteria

scholarly journals Salt-tolerant plant growth-promoting bacteria enhanced salinity tolerance of salt-tolerant alfalfa (Medicago sativa L.) cultivars at high salinity

2019 ◽  
Vol 41 (12) ◽  
Author(s):  
Mohammad Ansari ◽  
Farid Shekari ◽  
Mohammad Hossein Mohammadi ◽  
Katalin Juhos ◽  
György Végvári ◽  
...  
Keyword(s):  
Plant Growth ◽  
Medicago Sativa ◽  
High Salinity ◽  
Tap Water ◽  
Plant Growth Promoting Bacteria ◽  
Salt Tolerant ◽  
Chlorophyll Pigments ◽  
Nodule Number ◽  
Plant Growth Promoting ◽  
Growth Promoting

AbstractAlfalfa (Medicago sativa L.) plant growth decreases when cultivated under salinity or irrigated with salty water. Inoculation with plant growth-promoting bacteria (PGPB) is a method for mitigating the harmful effects of salinity on plants growth. To investigate salt-tolerant PGPB with salt-tolerant and salt-sensitive alfalfa cultivar interactions under salinity, some physiological and agronomical aspects were investigated. The inoculated plants of alfalfa cultivars with Hartmannibacter. diazotrophicus and Pseudomonas sp. bacteria were compared with non-inoculated plants. Plants were grown in growth room and irrigated with tap water until 6–7 weeks, and then, salinity stress imposed by irrigating with tap water (control), 10 dS m−1 and 20 dS m−1 NaCl. Salinity reduced relative water content (RWC), membrane stability index (MSI), K+, photosynthesis rate (Pn) and stomatal conductance (gs), leaf number, height, and dry weight, and increased sodium in all cultivars. Inoculation of cultivars with both PGPB mitigated the negative effects of salinity on plants growth by increasing the root length and weight, nodule number, chlorophyll pigments, RWC, MSI, Pn, and gs. Chlorophyll pigments, plant height and leaf number, Na+, K+/Na+, and nodule number improved more pronounced through inoculating with Pseudomonas sp., whereas K+, carotenoids, and RWC improved more pronounced through H. diazotrophicus under salinity. The results showed inoculation with two bacteria improved growth performance in salt-tolerant and salt-sensitive cultivars under 10 dS m−1, but at high salinity (20 dS m−1), inoculation was successful only in salt-tolerant alfalfa cultivars.

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.

scholarly journals Exploring biofertilizer potential of plant growth-promoting rhizobacteria Bacillus clausii strain B8 (MT305787) on Brassica napus and Medicago sativa

2021 ◽  
Vol 49 (4) ◽  
pp. 12484
Author(s):  
Hakima OULEBSIR-MOHANDKACI ◽  
Farida BENZINA-TIHAR ◽  
Rima HADJOUTI
Keyword(s):  
Acetic Acid ◽  
Brassica Napus ◽  
Plant Growth ◽  
Medicago Sativa ◽  
Inorganic Phosphate ◽  
Germination Rate ◽  
Plant Growth Promoting Rhizobacteria ◽  
Lytic Enzymes ◽  
Plant Growth Promoting ◽  
Growth Promoting

Plant Growth Promoting Rhizobacteria (PGPR) are soil bacteria that can stimulate plant growth by supplying substances that are usually in limited quantities in the soil especially phosphorous, nitrogen and growth hormone such as indole acetic acid (AIA). These bacteria can also slow the growth of plant pathogens through the production of several antimicrobial metabolites. To investigate the role of rhizobacteria as a biostimulant agent a novel bacterium B8, isolated from the rhizospheric soil of medlar (Mespilus germanica L.- Family Rosaceae), was evaluated on Brassica napus and Medicago sativa. In addition to the classical methods of identification (physiological and biochemical tests), B8 was identified by 16S rRNA gene sequencing as Bacillus clausii. The ability of the strain to produce lytic enzymes such as cellulases, chitinases, pectinases, and phospholipases was studied.  Furthermore, the strain B8 was tested for the capability to produce plant growth metabolites like phosphatases and phytases in order to solubilize inorganic phosphate and production of siderophores, cyanhydric acid (HCN) and indole-3-acetic acid. The strain was able to produce lytic enzymes, with an intense production of siderophores and to solubilize inorganic phosphate. Result of in vivo experiments indicated that the application of B8 at 107 CFU/mL, improved markedly the germination rate of rapeseed, whereas alfalfa seeds treated with the same strain showed a lower germination rate than the controls. The vegetative growth parameters; Roots length, lateral roots number, stem length, number of leaves, diameters of stems and plant weight were significantly improved. We also noted capacity of bacteria to colonize root systems of both plants B. napus and M. sativa in one week of inoculation.  The overall results of this study showed that B clausii B8 has a great potential to be commercialized as a biostimulant agent and provide promising new option for sustainable agriculture.

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