scholarly journals Multi-Omics Reveal the Efficient Phosphate-Solubilizing Mechanism of Bacteria on Rocky Soil

2021 ◽  
Vol 12 ◽  
Author(s):  
Yanqiang Ding ◽  
Zhuolin Yi ◽  
Yang Fang ◽  
Sulan He ◽  
Yuming Li ◽  
...  

Phosphate-solubilizing bacteria (PSB) can alleviate available phosphorus (AP)-deficiency without causing environmental pollution like chemical phosphate fertilizers. However, the research and application of PSB on the barren rocky soil is very rare. We screened six PSB from sweetpotato rhizosphere rocky soil. Among them, Ochrobactrum haematophilum FP12 showed the highest P-solubilizing ability of 1,085.00 mg/L at 7 days, which was higher than that of the most reported PSB. The assembled genome of PSB FP12 was 4.92 Mb with P-solubilizing and plant growth-promoting genes. In an AP-deficient environment, according to transcriptome and metabolomics analysis, PSB FP12 upregulated genes involved in gluconic acid synthesis and the tricarboxylic acid cycle, and increased the concentration of gluconic acid and malic acid, which would result in the enhanced P-solubilizing ability. Moreover, a series of experiments in the laboratory and field confirmed the efficient role of the screened PSB on significantly increasing AP in the barren rocky soil and promoting sweetpotato yield. So, in this study, we screened highly efficient PSB, especially suitable for the barren rocky soil, and explored the P-solubilizing mechanism. The research will reduce the demand for chemical phosphate fertilizers and promote the environment-friendly agricultural development.

2021 ◽  
Vol 11 ◽  
Author(s):  
Jinge Xie ◽  
Zongqiang Yan ◽  
Guifen Wang ◽  
Wenzhi Xue ◽  
Cong Li ◽  
...  

Phosphorus in the soil accessible to plants can easily be combined with calcium ion, the content of which is high in karst rocky desertification (KRD) regions, thereby resulting in a low utilization efficiency of phosphorus. The application of phosphate-solubilizing bacteria (PSB) from the KRD region would facilitate enhanced phosphate availability in the soil. In the present study, the strains belonging to Acinetobacter, Paraburkholderia, and Pseudomonas with efficient phosphate-solubilizing ability were isolated from fruit tree rhizosphere soils in KRD regions. Particularly, Acinetobacter sp. Ac-14 had a sustained and stable phosphate-solubilizing ability (439–448 mg/L, 48–120 h). Calcium carbonate decreased the phosphate-solubilizing ability in liquid medium; however, it did not affect the solubilization index in agar-solidified medium. When cocultivated with Arabidopsis thaliana seedling, Ac-14 increased the number of lateral roots, fresh weight, and chlorophyll content of the seedlings. Metabolomics analysis revealed that Ac-14 could produce 23 types of organic acids, majorly including gluconic acid and D-(-)-quinic acid. Expression of Ac-14 glucose dehydrogenase gene (gcd) conferred Pseudomonas sp. Ps-12 with a sustained and stable phosphate-solubilizing ability, suggesting that the production of gluconic acid is an important mechanism that confers phosphate solubilization in bacteria. Moreover, Ac-14 could also produce indole acetic acid and ammonia. Collectively, the isolated Ac-14 from KRD regions possess an efficient phosphate-solubilizing ability and plant growth-promoting effect which could be exploited for enhancing phosphorus availability in KRD regions. This study holds significance for the improvement of soil fertility and agricultural sustainable development in phosphorus-deficient KRD regions.


Plants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1071
Author(s):  
Minchong Shen ◽  
Jiangang Li ◽  
Yuanhua Dong ◽  
Hong Liu ◽  
Junwei Peng ◽  
...  

Microbial treatment has recently been attracting attention as a sustainable agricultural strategy addressing the current problems caused by unreasonable agricultural practices. However, the mechanism through which microbial inoculants promote plant growth is not well understood. In this study, two phosphate-solubilizing bacteria (PSB) were screened, and their growth-promoting abilities were explored. At day 7 (D7), the lengths of the root and sprout with three microbial treatments, M16, M44, and the combination of M16 and M44 (Com), were significantly greater than those with the non-microbial control, with mean values of 9.08 and 4.73, 7.15 and 4.83, and 13.98 and 5.68 cm, respectively. At day 14 (D14), M16, M44, and Com significantly increased not only the length of the root and sprout but also the underground and aboveground biomass. Differential metabolites were identified, and various amino acids, amino acid derivatives, and other plant growth-regulating molecules were significantly enhanced by the three microbial treatments. The profiling of key metabolites associated with plant growth in different microbial treatments showed consistent results with their performances in the germination experiment, which revealed the metabolic mechanism of plant growth-promoting processes mediated by screened PSB. This study provides a theoretical basis for the application of PSB in sustainable agriculture.


Agronomy ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 127 ◽  
Author(s):  
Arjun Kafle ◽  
Kevin Cope ◽  
Rachel Raths ◽  
Jaya Krishna Yakha ◽  
Senthil Subramanian ◽  
...  

Phosphorus is an essential macronutrient required for plant growth and development. It is central to many biological processes, including nucleic acid synthesis, respiration, and enzymatic activity. However, the strong adsorption of phosphorus by minerals in the soil decreases its availability to plants, thus reducing the productivity of agricultural and forestry ecosystems. This has resulted in a complete dependence on non-renewable chemical fertilizers that are environmentally damaging. Alternative strategies must be identified and implemented to help crops acquire phosphorus more sustainably. In this review, we highlight recent advances in our understanding and utilization of soil microbes to both solubilize inorganic phosphate from insoluble forms and allocate it directly to crop plants. Specifically, we focus on arbuscular mycorrhizal fungi, ectomycorrhizal fungi, and phosphate-solubilizing bacteria. Each of these play a major role in natural and agroecosystems, and their use as bioinoculants is an increasing trend in agricultural practices.


2020 ◽  
Vol 1 (2) ◽  
pp. 37-51
Author(s):  
C. E. Oshoma ◽  
S. O. Nwodo ◽  
I. S. Obuekwe

The processing of cassava into value-added products is associated with discharge of effluents which contain substances that have adverse effect on the environment. Remediative activity of indigenous bacteria can be stimulated by supplementing effluents with phosphorus. Rock phosphate (RP) solubilization and enzymatic activities from bacteria on the cassava mill effluents (CME) contaminated soil was investigated. Soil mixed with varying concentrations of CME (0, 100, 200, 300, 400, 500 and 600 ml) and 10 g of RP were analyzed on days 0 and 16. Parameters analyzed were changes in pH, heterotrophic bacteria load, phosphate-solubilizing bacteria load, available phosphorus, acid phosphatase, cellulase and urease concentrations. The results showed that the medium containing 400 ml CME contaminated soil had the highest phosphate-solubilizing bacteria load (12.60 ± 2.08 x 106 cfu/ml), available phosphorus (126.00 ± 4.08 mg/kg), acid phosphatase (9.54 ± 0.51 mgN/g/min), cellulase (15.24 ± 0.81 mg/g/6h) and urease concentration (2.15±0.22 mg/g/2h). The control had the lowest phosphate-solubilizing bacteria load and enzymatic activity. Biostimulation of indigenous bacteria to enhance the degradation of cassava mill effluent-contaminated soil, using rock phosphate, showed promising results. This implies that rock phosphate solubilization by indigenous bacteria in CME-contaminated soils could be important for the remediation and reclamation of contaminated lands.


2020 ◽  
Vol 10 (2) ◽  
pp. 5161-5173

Phosphorus (P) is one of the essential macronutrients needed for the plant growth, other than nitrogen and potassium. Most phosphorus remains as insoluble form in soils and the plants only can uptake the phosphorus nutrient in soluble forms. Phosphate solubilizing bacteria (PSB) dissolves the phosphorus and make it available for plants. In this study, Soil samples were collected and screened for PSB on PK medium. PSB colonies with the highest phosphate solubilization ability were chosen and used for studying its rhizosphere effect on Capsicum frutescens by pot experiment.. It was evidenced that selected PSB strain could solubilize phosphate in PK medium and modified PK broth. Besides, it provided available phosphorus for plants and enhanced the plant growth in pot experiment.


2021 ◽  
Vol 12 ◽  
Author(s):  
Xiao Li Li ◽  
Xue Qiang Zhao ◽  
Xiao Ying Dong ◽  
Jian Feng Ma ◽  
Ren Fang Shen

Phosphorus (P) deficiency is one of the major factors limiting plant growth in acid soils, where most P is fixed by toxic aluminum (Al). Phosphate-solubilizing bacteria (PSBs) are important for the solubilization of fixed P in soils. Many PSBs have been isolated from neutral and calcareous soils, where calcium phosphate is the main P form, whereas PSBs in acid soils have received relatively little attention. In this study, we isolated a PSB strain from the rhizosphere of Lespedeza bicolor, a plant well adapted to acid soils. On the basis of its 16S rRNA gene sequence, this strain was identified as a Nguyenibacter species and named L1. After incubation of Nguyenibacter sp. L1 for 48 h in a culture medium containing AlPO4 as the sole P source, the concentration of available P increased from 10 to 225 mg L–1, and the pH decreased from 5.5 to 2.5. Nguyenibacter sp. L1 exhibited poor FePO4 solubilization ability. When the pH of non-PSB-inoculated medium was manually adjusted from 5.5 to 2.5, the concentration of available P only increased from 6 to 65 mg L–1, which indicates that growth medium acidification was not the main contributor to the solubilization of AlPO4 by Nguyenibacter sp. L1. In the presence of glucose, but not fructose, Nguyenibacter sp. L1 released large amounts of gluconic acid to solubilize AlPO4. Furthermore, external addition of gluconic acid enhanced AlPO4 solubilization and reduced Al toxicity to plants. We conclude that secretion of gluconic acid by Nguyenibacter sp. L1, which is dependent on glucose supply, is responsible for AlPO4 solubilization as well as the alleviation of Al phytotoxicity by this bacterial strain.


2020 ◽  
Vol 11 ◽  
Author(s):  
Luciana F. Brito ◽  
Marina Gil López ◽  
Lucas Straube ◽  
Luciane M. P. Passaglia ◽  
Volker F. Wendisch

Due to the importance of phosphorus (P) in agriculture, crop inoculation with phosphate-solubilizing bacteria is a relevant subject of study. Paenibacillus sonchi genomovar Riograndensis SBR5 is a promising candidate for crop inoculation, as it can fix nitrogen and excrete ammonium at a remarkably high rate. However, its trait of phosphate solubilization (PS) has not yet been studied in detail. Here, differential gene expression and functional analyses were performed to characterize PS in this bacterium. SBR5 was cultivated with two distinct P sources: NaH2PO4 as soluble phosphate source (SPi) and hydroxyapatite as insoluble phosphate source (IPi). Total RNA of SBR5 cultivated in those two conditions was isolated and sequenced, and bacterial growth and product formation were monitored. In the IPi medium, the expression of 68 genes was upregulated, whereas 100 genes were downregulated. Among those, genes involved in carbon metabolism, including those coding for subunits of 2-oxoglutarate dehydrogenase, were identified. Quantitation of organic acids showed that the production of tricarboxylic acid cycle-derived organic acids was reduced in IPi condition, whereas acetate and gluconate were overproduced. Increased concentrations of proline, trehalose, and glycine betaine revealed active osmoprotection during growth in IPi. The cultivation with hydroxyapatite also caused the reduction in the motility of SBR5 cells as a response to Pi depletion at the beginning of its growth. SBR5 was able to solubilize hydroxyapatite, which suggests that this organism is a promising phosphate-solubilizing bacterium. Our findings are the initial step in the elucidation of the PS process in P. sonchi SBR5 and will be a valuable groundwork for further studies of this organism as a plant growth-promoting rhizobacterium.


2007 ◽  
Vol 2 (3) ◽  
pp. 326-333 ◽  
Author(s):  
A. Vikram ◽  
H. Hamzehzarghani . ◽  
A.R. Alagawadi . ◽  
P.U. Krishnaraj . ◽  
B.S. Chandrashekar .

2017 ◽  
Vol 5 (1) ◽  
pp. 32-35 ◽  
Author(s):  
Lalmuankimi Khiangte ◽  
◽  
R. Lalfakzuala

The phosphate solubilizing bacteria (phosphobacteria) secrete organic acids and phosphatase enzymes which act on insoluble phosphates and convert the same into soluble forms thus providing available phosphorus to the plants. They are also known to produce amino acids, vitamins and growth promoting substance like indole acetic acid (IAA), which helps in better growth of plants. The present studyaimed to isolate and screen out phosphate solubilizing bacteria from soil rhizosphere using serial dilution technique on pikovskaya agar plate. An effort was also made to obtain bacterial isolates for producing phosphatase enzyme and to study the production of IAA in NBRIP media containing tryptophan as a substrate.A total of 17 strains were isolated from soil rhizosphere and all the strains were able to produce IAA and phosphatase enzyme in vitro condition.


Sign in / Sign up

Export Citation Format

Share Document