scholarly journals A Composite Bioinoculant Based on the Combined Application of Beneficial Bacteria and Fungi

Agronomy ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 220 ◽  
Author(s):  
Henrietta Allaga ◽  
Bettina Bóka ◽  
Péter Poór ◽  
Viktor Dávid Nagy ◽  
Attila Szűcs ◽  
...  

A composite soil bioinoculant containing beneficial bacteria and fungi was developed for biocontrol of plant pathogens, phosphorous mobilization, stem degradation, humification, and nitrogen fixation. A Trichoderma asperellum isolate with outstanding in vitro antagonistic abilities toward a series of plant pathogenic fungi was included as a potential biocontrol component. The selected strain was also shown to promote growth and increase photosynthetic activity of tomato plants. For phosphorous mobilization and stem degradation, a Trichoderma atrobrunneum strain was selected, which produced cellulose-degrading enzymes even in the absence of stem residues, while this ability increased 10–15-fold in the presence of ground maize stem. The strain was also shown to produce large amounts of enzymes liberating organically bound phosphorous, as well as cellulase and xylanase activities in solid-state fermentation on various plant residues. A Streptomyces albus strain with excellent peroxidase-producing abilities was selected as a potential humus-producing component, while an Azotobacter vinelandii strain with the potential to provide excess nitrogen for crops was included for nitrogen fixation. The assembled soil bioinoculant had positive effect on the uptake of certain important macro- and microelements (potassium, sodium, and manganese) from the soil by field-grown tomato plants. The applied screening strategy proved to be applicable for the assembly of a composite soil bioinoculant with notable application potentials.

Pathogens ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 613
Author(s):  
Alfredo Ambrico ◽  
Mario Trupo ◽  
Rosaria Magarelli ◽  
Roberto Balducchi ◽  
Angelo Ferraro ◽  
...  

Several bacteria pathogens are responsible for plant diseases causing significant economic losses. The antibacterial activity of Dunaliella salina microalgae extracts were investigated in vitro and in vivo. First, biomass composition was chemically characterized and subjected to extraction using polar/non-polar solvents. The highest extraction yield was obtained using chloroform:methanol (1:1 v/v) equal to 170 mg g−1 followed by ethanol (88 mg g−1) and hexane (61 mg g−1). In vitro examination of hexane extracts of Dunaliella salina demonstrated antibacterial activity against all tested bacteria. The hexane extract showed the highest amount of β-carotene with respect to the others, so it was selected for subsequent analyses. In vivo studies were also carried out using hexane extracts of D. salina against Pseudomonas syringae pv. tomato and Pectobacterium carotovorum subsp. carotovorum on young tomato plants and fruits of tomato and zucchini, respectively. The treated young tomato plants exhibited a reduction of 65.7% incidence and 77.0% severity of bacterial speck spot disease. Similarly, a reduction of soft rot symptoms was observed in treated tomato and zucchini fruits with a disease incidence of 5.3% and 12.6% with respect to 90.6% and 100%, respectively, for the positive control.


2009 ◽  
Vol 76 (3) ◽  
pp. 769-775 ◽  
Author(s):  
Pey-Shynan Jan ◽  
Hsu-Yuang Huang ◽  
Hueih-Min Chen

ABSTRACT The cationic lytic peptide cecropin B (CB), isolated from the giant silk moth (Hyalophora cecropia), has been shown to effectively eliminate Gram-negative and some Gram-positive bacteria. In this study, the effects of chemically synthesized CB on plant pathogens were investigated. The S50s (the peptide concentrations causing 50% survival of a pathogenic bacterium) of CB against two major pathogens of the tomato, Ralstonia solanacearum and Xanthomonas campestris pv. vesicatoria, were 529.6 μg/ml and 0.29 μg/ml, respectively. The CB gene was then fused to the secretory signal peptide (sp) sequence from the barley α-amylase gene, and the new construct, pBI121-spCB, was used for the transformation of tomato plants. Integration of the CB gene into the tomato genome was confirmed by PCR, and its expression was confirmed by Western blot analyses. In vivo studies of the transgenic tomato plant demonstrated significant resistance to bacterial wilt and bacterial spot. The levels of CB expressed in transgenic tomato plants (∼0.05 μg in 50 mg of leaves) were far lower than the S50 determined in vitro. CB transgenic tomatoes could therefore be a new mode of bioprotection against these two plant diseases with significant agricultural applications.


2012 ◽  
Vol 59 (2) ◽  
pp. 51-58 ◽  
Author(s):  
Alicja Saniewska ◽  
Anna Jarecka ◽  
Zbigniew Biały ◽  
Marian Jurzysta

Antifungal activity of total saponins originated from roots of <i>Medicago hybrida</i> (Pourret) Trautv. were evaluated <i>in vitro</i> against six pathogenic fungi and eight individual major saponin glycosides were tested against one of the most susceptible fungi. The total saponins showed fungitoxic effect at all investigated concentrations (0.01%, 0.05% and 0.1%) but their potency was different for individual fungi. The highest saponin concentration (0.1%) was the most effective and the inhibition of <i>Fusarium oxysporum</i> f. sp. <i>callistephi</i>, <i>Botrytis cinerea</i>, <i>Botrytis tulipae</i>, <i>Phoma narcissi</i>, <i>Fusarium oxysporum</i> f. sp. <i>narcissi</i> was 84.4%, 69.9%, 68.6%, 57.2%, 55.0%, respectively. While <i>Fusarium oxysporum</i> Schlecht., a pathogen of <i>Muscari armeniacum</i>, was inhibited by 9.5% only. Eight major saponin glycosides isolated from the total saponins of <i>M. hybrida</i> roots were tested against the mycelium growth of <i>Botrytis tulipae</i>. The mycelium growth of the pathogen was greatly inhibited by hederagenin 3-O-<i>β</i>-D-glucopyranoside and medicagenic acid 3-O-<i>β</i>-D-glucopyranoside. Medicagenic acid 3-O-<i>β</i>-D-glucuronopyranosyl-28-O-<i>β</i>-D-glucopyranoside and oleanolic acid 3-O-[<i>β</i>-D-glucuronopyranosyl(1→2)-<i>α</i>-L-galactopyranosyl]-28-O-<i>β</i>-D-glucopyranoside showed low fungitoxic activity. Medicagenic acid 3-O-a-D-glucopyranosyl- 28-O-β-D-glucopyranoside, hederagenin 3-O-[α-L- hamnopyranosyl(1→2)-β-D-glucopyranosyl(1→2)-β-D-glucopyranosyl]- 28-O-α-D-glucopyranoside and hederagenin 3-O-<i>β</i>-D-glucuronopyranosyl-28-O-<i>β</i>-D- lucopyranoside did not limit or only slightly inhibited growth of the tested pathogen. While 2<i>β</i>, 3<i>β</i>-dihydroxyolean-12 ene-23-al-28-oic acid 3-O-<i>β</i>-D-glucuronopyranosyl-28-O-<i>β</i>-D-glucopyranoside slightly stimulated mycelium growth of <i>B. tulipae</i>.


2017 ◽  
Vol 9 (2) ◽  
pp. 860-865 ◽  
Author(s):  
Shubhransu Nayak ◽  
Archana Mukherjee ◽  
Soma Samanta

Endophytic microorganisms which include both bacteria and fungi colonise almost every plant species. In order to colonize the plant and compete with other microorganisms, they produce a plethora of secondary metabolites, including toxins, enzymes, antibiotics, anti-cancer, anti-inflammatory and antifungal compounds. Endophytic fungi can have profound impacts on plant communities which include abiotic and biotic stress tolerance, increase of biomass, decrease of water consumption and alteration of resource allocation, nitrogen fixation, increased drought resistance, thermal protection, survival under osmotic stress and degradation of pollutants. Though tuber crops are the second most important group of crop plants providing food energy to humans after cereals, less attention has been paid to the these traditional crops in general. Investigations regarding the association of endophytes with the tuber crops have been sparsely studied though in some tuber crops like cassava, sweet potato and yams, presence of endophytes have been reported. Hence from the scarcely available literature, in the current review an attempt was made to put light on the various beneficial activities of endophytes on tuber crops. These reports glorified many symbiotically associated endophytes to have antagonistic properties against many plant pathogens like Rhizoctoniasolani, Pythiumaphanidermatumand Sclerotiumrolfsii. Species like Rahnellawas resilient to cold shock, UV irradiation and antibiotics. Many diazotropihic and non-diazotropihicendophytic bacteria were involved in nitrogen fixation. Actinomycetesendophytes were novel sources of industrially important thermostableamylolytic enzymes. However, inspite of all these profound beneficial effects endophytic associations are still to be studied in many tuber crops like taro, elephant foot yam, greater yam etc. So this review put forward the urge to carry out comprehensive research on these important microbes on such important crops.


2020 ◽  
Author(s):  
Pingliang Li ◽  
jian zou ◽  
Yanhan Dong ◽  
jintao Jiang ◽  
Wenxing Liang ◽  
...  

Tetrandrine (TET) is a potent calcium channel blocker used for the treatment of hypertension and inflammation. Currently, TET is predominantly used to treat a variety of human diseases, and there is little information regarding the use of TET against plant pathogens. In this study, we explored the antifungal activity of TET on a plant pathogen, Botrytis cinerea. We show that administration of low concentrations of TET effectively inhibited hyphal growth of fungus grown on potato dextrose agarose, and decreased the virulence of B. cinerea in tomato plants. Real-time PCR revealed that the expression of drug efflux pump related genes (alcohol dehydrogenase 1, multi-drug/pheromone exporter, pleiotropic drug resistance protein 1, and synaptic vesicle transporter) were down-regulated in the presence of TET. Finally, we show that TET acts synergistically with iprodione, resulting in increased inhibition of B. cinerea both in vitro and in vivo. These results indicate that TET might act as an effective antifungal agent in reducing grey mold disease.


2021 ◽  
Vol 18 ◽  
Author(s):  
Shivani Loomba ◽  
Divya Utreja ◽  
Komalpreet Kaur ◽  
Jaspal Kaur ◽  
Shivali Sharma ◽  
...  

: Schiff bases of isatin were synthesized by reacting isatin with substituted aromatic amines and were characterized by UV-Visible, 1HNMR, 13CNMR, IR, and microanalytical data. All the synthesized isatin Schiff bases were screened in vitro against wheat pathogenic fungi Bipolaris sorokiniana, Alternaria triticina using spore inhibition technique and brinjal parasite- Meloidogyne incognita by egg hatch inhibition and J2 mortality. The in vitro study and docking simulation studies revealed that the 3-(2,4,5-trichlorophenylimino)indolin-2-one 6f and 3-(2,4-dinitrophenylimino)indolin-2-one 6c substituted with tri-halogen and dinitro electron-withdrawing groups were found to be promising antipathogenic candidates. The possible binding interactions of tested compounds with Aspartyl protease and Acetylcholine binding proteins were analyzed through molecular docking.


2008 ◽  
Vol 21 (6) ◽  
pp. 728-736 ◽  
Author(s):  
Yolanda Pareja-Jaime ◽  
M. Isabel G. Roncero ◽  
M. Carmen Ruiz-Roldán

Saponin detoxification enzymes from pathogenic fungi are involved in the infection process of their host plants. Fusarium oxysporum f. sp lycopersici, a tomato pathogen, produces the tomatinase enzyme Tom1, which degrades α-tomatine to less toxic derivates. To study the role of the tom1 gene in the virulence of F. oxysporum, we performed targeted disruption and overexpression of the gene. The infection process of tomato plants inoculated with transformants constitutively producing Tom1 resulted in an increase of symptom development. By contrast, tomato plants infected with the knockout mutants showed a delay in the disease process, indicating that Tom1, although not essential for pathogenicity, is required for the full virulence of F. oxysporum. Total tomatinase activity in the disrupted strains was reduced only 25%, leading to β2-tomatine as the main hydrolysis product of the saponin in vitro. In silico analysis of the F. oxysporum genome revealed the existence of four additional putative tomatinase genes with identities to tomatinases from family 3 of glycosyl hydrolases. These might be responsible for the remaining tomatinase activity in the Δtom1 mutants. Our results indicate that detoxification of α-tomatine in F. oxysporum is carried out by several tomatinase activities, suggesting the importance of these enzymes during the infection process.


2021 ◽  
Vol 12 ◽  
Author(s):  
Zhen Wang ◽  
Manoj Kumar Solanki ◽  
Zhuo-Xin Yu ◽  
Muhammad Anas ◽  
Deng-Feng Dong ◽  
...  

To understand the beneficial interaction of sugarcane rhizosphere actinobacteria in promoting plant growth and managing plant diseases, this study investigated the potential role of sugarcane rhizospheric actinobacteria in promoting plant growth and antagonizing plant pathogens. We isolated 58 actinobacteria from the sugarcane rhizosphere, conducted plant growth-promoting (PGP) characteristics research, and tested the pathogenic fungi in vitro. Results showed that BTU6 (Streptomyces griseorubiginosus), the most representative strain, regulates plant defense enzyme activity and significantly enhances sugarcane smut resistance by regulating stress resistance-related enzyme (substances (POD, PAL, PPO, TP) in sugarcane) activity in sugarcane. The genomic evaluation indicated that BTU6 has the ability to biosynthesize chitinase, β-1,3-glucanase, and various secondary metabolites and plays an essential role in the growth of sugarcane plants under biotic stress. Potential mechanisms of the strain in improving the disease resistance of sugarcane plants and its potential in biodegrading exogenous chemicals were also revealed. This study showed the importance of sugarcane rhizosphere actinobacteria in microbial ecology and plant growth promotion.


Horticulturae ◽  
2021 ◽  
Vol 7 (12) ◽  
pp. 573
Author(s):  
Hosapura Shekhararaju Mahesha ◽  
Jayasuvarnapura Umapathi Vinay ◽  
Medikeripura Rekhyanaik Ravikumar ◽  
Suryanarayana Visweswarashastry ◽  
Manikyanahalli Chandrashekhara Keerthi ◽  
...  

Plant pathogenic fungi and bacteria are a significant threat to global commercial crop production resulting in increased cost of production, reduced crop establishment and productivity. An effort was made to study the antimicrobial activity of silver hydrogen peroxide (SHP) against selected plant pathogenic fungi and bacteria under in vitro conditions. Higher antibacterial activity of SHP was observed against Xanthomonas axonopodis pv. citri (Xac; 39.67 mm), Xanthomonas citri pv. punicae (Xap; 39.00 mm), and Ralstonia solanacearum (Rs; 36.67 mm) at 500 ppm concentration. SHP was superior to streptocycline (500 ppm) against Xac (25.33 mm) and Xcp (22.67 mm) at 100 ppm. The soil-borne fungi viz., Pythium aphanidermatum and Fusarium solani failed to initiate mycelium growth on PDA at the concentration of 5000 ppm and above. The average size of SHP particles was 462 nm in diameter, and 73.40% of particles had the size of 378 nm, which reflects the particles present in SHP solution in the form of colloids. The effective doses (100–5000 ppm) did not show any phytotoxicity symptoms in plants, while leaf necrosis was noticed at 10,000 ppm after four days of application. SHP (≤5000 ppm) can be used to effectively manage both fungal and bacterial plant pathogens by a single application. Further field studies need to be conducted for validation and commercial use of SHP.


Sign in / Sign up

Export Citation Format

Share Document