scholarly journals Evaluating the salt resistance of Arabidopsis thaliana induced by plant growth-promoting rhizobacteria (PGPR) isolated from Can Gio mangrove forest

Author(s):  
Trinh Le Phuong Ngo ◽  
Thanh Nguyen Chu ◽  
Thanh Nguyen Chu ◽  
Minh Thi Thanh Hoang

As soil salinization is a major concern of modern agriculture and an expected threat in climate change scenarios, special effort will be required for maintaining crop production under salt stress. The use of plant growth-promoting rhizobacteria (PGPR) is a promising agricultural practice to help less salt tolerant crops to maintain an acceptable level of productivity under higher salt concentrations. Here, we have isolated the PGPR from the rhizosphere soil in Can Gio Mangrove Forest, Vietnam. Fifteen isolates of bacteria were successfully isolated on medium containing 10 % NaCl. Subsequently, to investigate the effects of PGPR isolates on the growth of Arabidopsis thaliana, seeds were treated with the PGPR and observed the germination as well as the seedling growth. Under stress condition, all bacteria inhibited the germination, however, 02NP01, 04PP02 and 06NS01, identified as Bacillus thuringiensis, Vibrio and Halomonas elongata, respectively, could promote Arabidopsis thaliana seedling growth compared to the control. Further analysis found that three bacteria exhibited the ability to fix nitrogen, solubilize inorganic phosphorus and produce phytohormone-auxin. In addition, under normal condition, Bacillus and Vibrio significantly increased A. thaliana germination, after treatment with Bacillus and Vibrio the seed germination rate increased by 36.60 % and 69.76 % respectively compared to the control. Our research shows that isolated potential rhizobacterial strains may be used as an effective tool for enhancing Arabidopsis thaliana seedling growth under salinity stress.

2000 ◽  
Vol 30 (6) ◽  
pp. 845-854 ◽  
Author(s):  
Masahiro Shishido ◽  
Christopher P Chanway

Seeds of two hybrid spruce (Picea glauca (Moench) Voss × Picea engelmannii Parry ex Engelm.) ecotypes were inoculated with one of six plant growth-promoting rhizobacteria (PGPR) strains previously shown to be able to stimulate spruce growth in controlled environments. The resulting seedlings were grown in the greenhouse for 17 weeks before outplanting at four reforestation sites. Inoculation with five of the six strains caused significant seedling growth promotion in the greenhouse, which necessitated analysis of relative growth rates (RGR) to evaluate seedling performance in the field. Four months after outplanting, most strains enhanced spruce shoot or root RGRs in the field, but seedling growth responses were strain specific. For example, Pseudomonas strain Ss2-RN significantly increased both shoot and root RGRs by 10-234% at all sites, but increases of 28-70% were most common. In contrast, Bacillus strain S20-R was ineffective at all outplanting sites. In addition, seedlings inoculated with four of the six strains had significantly less shoot injury than control seedlings at all sites. Evaluation of root colonization by PGPR indicated that bacterial population declines were not related to spruce growth response variability in the field. Our results indicate that once plant growth promotion is induced in the greenhouse, seedling RGR can increase by more than 100% during the first growing season in the field. However RGR increases of 21-47% were more common and may be more representative of the magnitude of biomass increases that can result from PGPR inoculation.


Author(s):  
Di Fan ◽  
Donald L. Smith

There are pressing needs to reduce the use of agrochemicals, and PGPR are receiving increasing interest in plant growth promotion and disease protection. This study follows up our previous report that the four newly isolated rhizobacteria promote the growth of Arabidopsis thaliana .


2019 ◽  
Vol 20 (12) ◽  
Author(s):  
Haliatur Rahma ◽  
NURBAILIS ◽  
NILA KRISTINA

Abstract. Rahma H, Nurbailis, Kristina N. 2019. Characterization and potential of plant growth-promoting rhizobacteria on rice seedling growth and the effect on Xanthomonas oryzae pv. oryzae. Biodiversitas 20: 3654-3661. Xanthomonas oryzae pv. oryzae (Xoo), a major limiting factor in rice production, and the use of resistant Xoo varieties have failed to control the bacterial pathogens as well as increased yield. It is due to the diversity in pathotypes, caused by environmental factors, the nature of resistant variety used, and gene mutation. The aims of this study were to select rhizobacterial strains with the potential of suppressing Xoo growth and promoting the growth of rice seedlings. This experiment was conducted in a completely randomized design (CRD) using seven rhizobacterial isolates selected through a dual culture test, with four replications. There were four isolates that potential in inhibiting the growth of Xoo, namely KJKB5.4, LMTSA5.4, Bacillus cereus AJ34, and Alcaligenes faecalis AJ14, with inhibition diameters greater than 11.50 mm. Rhizobacterial supernatant of 4 potential isolates has a zone of inhibition ranging from 12.25 to 24.00 mm. Four potential isolates were also able to solubilize phosphate, produce indole acetic acid (IAA) growth hormone, and siderophore, as well as enhance the growth of rice seedlings. Based on the nucleic acid sequencing of LMTSA5.4, KJKB5.4, and RK12 isolates were identified as Stenotrophomonas malthopilia strain LMG 958 (99.13%) accession NR 119220.1, Stenotrophomonas pavanii strain LMG 25348 (95.84%) accession NR 118008.1 and Ochrobactrum ciceri strain ca-34 (92.91%) accession NR115819.1.


2001 ◽  
Vol 28 (9) ◽  
pp. 975
Author(s):  
Kenneth J. O'Callaghan ◽  
Richard A. Dixon ◽  
Edward C. Cocking

This paper originates from an address at the 8th International Symposium on Nitrogen Fixation with Non-Legumes, Sydney, NSW, December 2000 Arabidopsis thaliana L. has many features favoring its use as a model in studies of plant-growth-promoting rhizobacteria (PGPR), such as diazotrophs. Several niches are colonized in the root system of Arabidopsis, including xylem, and intact colonized roots can be observed microscopically without sectioning of tissues. Studies of plant genes involved in colonization are facilitated by the ease with which plants are transformed and by the availability of mutant lines and other accessions obtainable from stock centers. Lines of Arabidopsis carrying reporter gene fusions are helping to reveal the pattern of expression of previously cloned plant genes induced by rhizobacteria. Studies utilizing indole-3-acetic acid (IAA)-producing PGPR and Arabidopsis that contain an auxin-responsive GUS fusion suggest that plants perceive IAA released by bacteria in the rhizosphere. The role of flavonoids in the colonization of non-legumes is being assessed using transgenic Arabidopsis with altered flavonoid metabolism and using tt mutants, which lack functional versions of specific genes for flavonoid metabolism. Studies of plant defence and of stress responses are producing molecular data on plant genes induced by inoculation of Arabidopsis roots with non-pathogens.


2019 ◽  
Vol 70 (8) ◽  
pp. 649
Author(s):  
Noura Bechtaoui ◽  
Abdelkhalek El Alaoui ◽  
Anas Raklami ◽  
Loubna Benidire ◽  
Abdel-ilah Tahiri ◽  
...  

Intercropping is a farming practice that fights pests and diseases and improves plant growth. The use of plant growth-promoting rhizobacteria (PGPR) strains to boost the yield of intercrops constitutes a promising tool in agricultural practice. This study investigated the impact of single inoculation and co-inoculation with PGPR on plant biomass and phosphorus (P) and nitrogen (N) concentrations under different cropping systems. Two PGPR strains with different traits were selected: PGP13 (Rahnella aquatilis) and PS11 (Pseudomonas sp.). A greenhouse experiment was designed using durum wheat (Triticum durum L.) and faba bean (Vicia faba L.), sole cropped or intercropped, including four inoculation treatments: (i) uninoculated, (ii) inoculated with PS11 (iii) inoculated with PGP13, and (iv) co-inoculated with PS11 + PGP13. Co-inoculation under the intercropping system improved plant dry matter and enhanced bean pod and wheat spike weights to 685.83% and 385.83%, respectively, of the values for uninoculated, intercropped plants. Higher P and N concentrations were detected in intercropped, co-inoculated plants and in bean pods and wheat spikes. The results were then submitted to principal component analysis, showing that treatments with higher biomass and nutrient concentrations were strongly correlated with intercropped, co-inoculated plants.


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