Interactive effect of biochar and plant growth-promoting bacterial endophytes on ameliorating salinity stress in maize

2015 ◽  
Vol 42 (8) ◽  
pp. 770 ◽  
Author(s):  
Saqib Saleem Akhtar ◽  
Mathias Neumann Andersen ◽  
Muhammad Naveed ◽  
Zahir Ahmad Zahir ◽  
Fulai Liu

The objective of this work was to study the interactive effect of biochar and plant growth-promoting endophytic bacteria containing 1-aminocyclopropane-1-carboxylate deaminase and exopolysaccharide activity on mitigating salinity stress in maize (Zea mays L.). The plants were grown in a greenhouse under controlled conditions, and were subjected to separate or combined treatments of biochar (0% and 5%, w/w) and two endophytic bacterial strains (Burkholderia phytofirmans (PsJN) and Enterobacter sp. (FD17)) and salinity stress. The results indicated that salinity significantly decreased the growth of maize, whereas both biochar and inoculation mitigated the negative effects of salinity on maize performance either by decreasing the xylem Na+ concentration ([Na+]xylem) uptake or by maintaining nutrient balance within the plant, especially when the two treatments were applied in combination. Moreover, in biochar-amended saline soil, strain FD17 performed significantly better than did PsJN in reducing [Na+]xylem. Our results suggested that inoculation of plants with endophytic baterial strains along with biochar amendment could be an effective approach for sustaining crop production in salt-affected soils.

2021 ◽  
Author(s):  
Sajid Rashid Ahmad ◽  
Sana Ashraf ◽  
Humaira Nawaz

Saline soil is one of the common environmental issues that negatively affects the soil quality of agricultural lands. It reduces the plant growth and productivity worldwide. Soil Salinity and sodicity affecting land about 1128 million hectares globally determined by recent researches. The most important salt-sensitive cereal crops in the world are Maize (Zea mays L.) For food security, its need of hour to securing attainable production of maize crop in the salt affected soils. To reduce negative impacts of saline soil on plant growth, sustainable approaches such as organic amendments like press mud and inorganic amendments like silicon can be applied. For increasing crop productivity, plant growth promoting rhizobacteria (PGPR) which are salt-tolerant in saline agriculture can also be applied. In this book chapter interactive effect of different organic and inorganic amendments and plant growth-promoting rhizobacteria to reduce salinity stress on maize has been discussed.


PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e6076 ◽  
Author(s):  
Hadia -e- Fatima ◽  
Ambreen Ahmed

Bacteria are tiny organisms which are ubiquitously found in the environment. These microscopic living bodies are responsible for the flow of nutrients in biogeochemical cycles and fertility imparted to the soil. Release of excessive chromium in agricultural soils due to rapid growth of industries may result in minimizing the fertility of soil in future, which will lead to reduction in crop production. Plant growth promoting bacteria (PGPB) are beneficial to the environment, some of which can tolerate chromium and protect plants against heavy metal stress. The current study aims to identify such chromium-tolerant auxin-producing rhizobacteria and to investigate their inoculation effects on the growth characteristics of Lens culinaris in chromium polluted soils by using two different chromium salts i.e., K2Cr2O7 and K2CrO4 in varying concentrations (0, 50, 100, 200, 400 and 500 µgml−1). The results revealed that Bacillus species are efficient in significantly reducing the deleterious effects of Cr. These effective bacterial strains were able to stimulate the growth of metal effected plants of Lens culinaris which were grown in chromium contaminated environment. Therefore, these plant growth promoting rhizobacteria PGPRs, having both auxin production potential and chromium-resistance ability, are considered as efficient micro-factories against chromium pollution.


2020 ◽  
Vol 10 (2) ◽  
pp. 44-53
Author(s):  
Sana Shakeel ◽  
Ifrah Javaid ◽  
Ambreen Ahmed

Background: Rhizosphere is a soil region closest to roots of the plants inhabiting different types of microorganisms including rhizobacteria. Chemical fertilizers which are conventionally used for increasing crop production are dangerous in terms of minimizing the nutritional value of crops and may also be hazardous for biological agents. Therefore, the use of Plant Growth Promoting Rhizobacteria (PGPR) are favorable for improved crop production over chemical fertilizers. Objectives: The current study highlights the growth promoting traits of bacterial isolates through isolation of rhizospheric bacterial strains from different plants. Methodology: In this study, ten rhizospheric bacterial isolates were used, which were morpho-physiologically characterized and then tested for plant growth-promoting traits i.e., HCN production, ammonification and auxin production. Most of the bacterial strains gave positive results for these plant growth-promoting traits. To study the beneficial effects of these bacteria on plants, plant-microbial interaction assay was conducted using Zea mays. Results: Results revealed that these bacteria enhanced the growth as compared to control plants. Bacterial isolates Streptomyces lydicus (Cn6), Staphylococcus aureus (Cn7) and Bacillus pumilus (PP3) showed strong ammonia producing effects. The isolates Bacillus subtilis (Cn2), PP2 and PP5 exhibited strong potential of HCN production whereas only Streptomyces lydicus (Cn6) and Bacillus pumilus (PP3) were observed to be auxin producers. A maximum increase in fresh weight of the plants was observed in treatment with PP2 showing 94.36% increase over controls. Cn1 showed an increase (26.12%) in shoot length while Cn5 revealed a prominent increase (64.95%) in root length compared to the control plant. The isolates Cn5 and Cn4 showed improvement in the total chlorophyll content of the treated plants with a percentage increase of 100% and 99.82%, respectively compared to the control. Conclusion: In conclusion, these PGPR may be further used in agriculture research for growth improvement.


2016 ◽  
Vol 43 (7) ◽  
pp. 632 ◽  
Author(s):  
Aizheng Yang ◽  
Saqib Saleem Akhtar ◽  
Shahid Iqbal ◽  
Muhammad Amjad ◽  
Muhammad Naveed ◽  
...  

Quinoa is a facultative halophytic seed crop of increasing interest worldwide. Its performance declines under high salinity but can be improved by using halotolerant plant growth-promoting bacteria (PGPB) containing multi-traits, i.e. ACC-deaminase activity, exopolysaccharide secretion and auxin production. This study focussed on improving the productivity of quinoa through the use of six plant growth-promoting bacterial strains (both endophytic and rhizosphere). These were screened by conducting osmoadaptation assay, and the two most halotolerant strains (Enterobacter sp. (MN17) and Bacillus sp. (MN54)) were selected. These two strains were evaluated for their effects on growth, physiological characters and yield of quinoa. At the five leaf stage plants were irrigated with saline water having either 0 or 400 mM NaCl. The results indicated that saline irrigation significantly decreased the growth of quinoa, whereas inoculation of plants with MN17 and MN54 mitigated the negative effects of salinity by improving plant water relations and decreasing Na+ uptake, which consequently, reduced osmotic and ionic stress. Strain MN54 performed better than MN17, which might be because of its better growth promoting traits and higher rhizosphere colonisation efficiency than MN17. Our results suggest that growth and productivity of quinoa could be improved by inoculating with highly tolerant PGPB strain in salt-affected soils.


Plants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 912
Author(s):  
Shuming Liu ◽  
Hongmei Liu ◽  
Rui Chen ◽  
Yong Ma ◽  
Bo Yang ◽  
...  

Miscanthus spp. are energy plants and excellent candidates for phytoremediation approaches of metal(loid)s-contaminated soils, especially when combined with plant growth-promoting bacteria. Forty-one bacterial strains were isolated from the rhizosphere soils and roots tissue of five dominant plants (Artemisia argyi Levl., Gladiolus gandavensis Vaniot Houtt, Boehmeria nivea L., Veronica didyma Tenore, and Miscanthus floridulus Lab.) colonizing a cadmium (Cd)-contaminated mining area (Huayuan, Hunan, China). We subsequently tested their plant growth-promoting (PGP) traits (e.g., production of indole-3-acetic acid, siderophore, and 1-aminocyclopropane-1-carboxylate deaminase) and Cd tolerance. Among bacteria, two strains, Klebsiella michiganensis TS8 and Lelliottia jeotgali MR2, presented higher Cd tolerance and showed the best results regarding in vitro growth-promoting traits. In the subsequent pot experiments using soil spiked with 10 mg Cd·kg−1, we investigated the effects of TS8 and MR2 strains on soil Cd phytoremediation when combined with M. floridulus (Lab.). After sixty days of planting M. floridulus (Lab.), we found that TS8 increased plant height by 39.9%, dry weight of leaves by 99.1%, and the total Cd in the rhizosphere soil was reduced by 49.2%. Although MR2 had no significant effects on the efficiency of phytoremediation, it significantly enhanced the Cd translocation from the root to the aboveground tissues (translocation factor > 1). The combination of K. michiganensis TS8 and M. floridulus (Lab.) may be an effective method to remediate Cd-contaminated soils, while the inoculation of L. jeotgali MR2 may be used to enhance the phytoextraction potential of M. floridulus.


2021 ◽  
Vol 9 (8) ◽  
pp. 1588
Author(s):  
Anastasia Venieraki ◽  
Styliani N. Chorianopoulou ◽  
Panagiotis Katinakis ◽  
Dimitris L. Bouranis

Plant growth promoting rhizobacteria (PGPR) can be functional microbial fertilizers and/or biological control agents, contributing to an eco-spirit and safe solution for chemical replacement. Therefore, we have isolated rhizospheric arylsulfatase (ARS)-producing bacteria, belonging to Pseudomonas and Bacillus genus, from durum wheat crop grown on calcareous soil. These isolates harbouring plant growth promoting (PGP) traits were further evaluated in vitro for additional PGP traits, including indole compounds production and biocontrol activity against phytopathogens, limiting the group of multi-trait strains to eight. The selected bacterial strains were further evaluated for PGP attributes associated with biofilm formation, compatibility, salt tolerance ability and effect on plant growth. In vitro studies demonstrated that the multi-trait isolates, Bacillus (1.SG.7, 5.SG.3) and Pseudomonas (2.SG.20, 2.C.19) strains, enhanced the lateral roots abundance and shoots biomass, mitigated salinity stress, suggesting the utility of beneficial ARS-producing bacteria as potential microbial fertilizers. Furthermore, in vitro studies demonstrated that compatible combinations of multi-trait isolates, Bacillus sp. 1.SG.7 in a mixture coupled with 5.SG.3, and 2.C.19 with 5.SG.3 belonging to Bacillus and Pseudomonas, respectively, may enhance plant growth as compared to single inoculants.


Agronomy ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 888
Author(s):  
Giorgia Novello ◽  
Patrizia Cesaro ◽  
Elisa Bona ◽  
Nadia Massa ◽  
Fabio Gosetti ◽  
...  

The reduction of chemical inputs due to fertilizer and pesticide applications is a target shared both by farmers and consumers in order to minimize the side effects for human and environmental health. Among the possible strategies, the use of biostimulants has become increasingly important as demonstrated by the fast growth of their global market and by the increased rate of registration of new products. In this work, we assessed the effects of five bacterial strains (Pseudomonas fluorescens Pf4, P. putida S1Pf1, P. protegens Pf7, P. migulae 8R6, and Pseudomonas sp. 5Vm1K), which were chosen according to their previously reported plant growth promotion traits and their positive effects on fruit/seed nutrient contents, on a local onion cultivar and on zucchini. The possible variations induced by the inoculation with the bacterial strains on the onion nutritional components were also evaluated. Inoculation resulted in significant growth stimulation and improvement of the mineral concentration of the onion bulb, induced particularly by 5Vm1K and S1Pf1, and in different effects on the flowering of the zucchini plants according to the bacterial strain. The present study provides new information regarding the activity of the five plant growth-promoting bacteria (PGPB) strains on onion and zucchini, two plant species rarely considered by the scientific literature despite their economic relevance.


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