scholarly journals Diversity analysis of antagonistic microbes against bacterial leaf and fungal sheath blight diseases of rice

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Chinnaswami Kannan ◽  
Divya Mishra ◽  
Gonuguntala Rekha ◽  
Pesari Maruthi ◽  
Hajira Shaik ◽  
...  

Abstract Background Biocontrol is an effective strategy in the integrated management of plant diseases, now more as a necessity than choice, in the present era of environmental and health awareness. Microbial diversity is a wonder by nature that inspires to explore and accordingly, the diversity analysis of the isolated microbes revealed their morphological and molecular differences. The DNA provides a common platform to store the microbial information in the form of databases in public domain that can be used by anyone from anywhere. Results Exploration for native microbes in the present study resulted in isolation of different isolates of Trichoderma and Bacillus. The microbes were identified using morphological traits and molecular markers and the key conserved 18S and 16S gene sequences submitted with the appropriate repositories. Nucleotide analysis indicated a close phylogenetic relationship between BIK 2 and BIK 3 (Bacillus isolates) and within all the 5 Trichoderma isolates. The percent disease reduction of Rhizoctonia solani and Xanthomonas oryzae pv. oryzae (Xoo) was more in plants treated with consortia of the Trichoderma (61.13%) and Bacillus (53.59%) isolates, respectively. Screening of plant growth promotion activities, percentage increase in root (41.00%) and shoot length (44.77%) were found to be maximum in Trichoderma consortia treated plants. Conclusions Three Bacillus and one Trichoderma strains, viz., B. velezensis, B. subtilis and B. paralicheniformis and Trichoderma asperellum, were identified and found to be effective against R. solani and Xoo pathogens of rice. In vitro and in vivo studies indicated that TAIK1 and BIK3 were found to be the most potential isolates among others isolated. Ability to improve plant growth was more pronounced by consortia of microbes.

2019 ◽  
Vol 7 (10) ◽  
pp. 384 ◽  
Author(s):  
Valentina Riva ◽  
Francesca Mapelli ◽  
Evdokia Syranidou ◽  
Elena Crotti ◽  
Redouane Choukrallah ◽  
...  

The microbiome associated with plants used in phytodepuration systems can boost plant growth and services, especially in ecosystems dealing with recalcitrant compounds, hardly removed via traditional wastewater (WW) treatments, such as azo-dyes used in textile industry. In this context, we aimed to study the cultivable microbiome selected by Phragmites australis plants in a Constructed Wetland (CW) in Morocco, in order to obtain candidate inoculants for the phytodepuration of azo-dye contaminated WW. A collection of 152 rhizospheric and endophytic bacteria was established. The strains were phylogenetically identified and characterized for traits of interest in the phytodepuration context. All strains showed Plant Growth Promotion potential in vitro and 67% of them significantly improved the growth of a model plant in vivo compared to the non bacterized control plants. Moreover, most of the isolates were able to grow in presence of several model micropollutants typically found in WW, indicating their potential use in phytodepuration of a wide spectrum of effluents. The six most promising strains of the collection were tested in CW microcosms alone or as consortium: the consortium and two single inocula demonstrated to significantly increase the removal of the model azo-dye Reactive Black 5 compared to the non bacterized controls.


Biology ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 140
Author(s):  
Farideh Ghadamgahi ◽  
Saeed Tarighi ◽  
Parissa Taheri ◽  
Ganapathi Varma Saripella ◽  
Alice Anzalone ◽  
...  

P. aeruginosa strain FG106 was isolated from the rhizosphere of tomato plants and identified through morphological analysis, 16S rRNA gene sequencing, and whole-genome sequencing. In vitro and in vivo experiments demonstrated that this strain could control several pathogens on tomato, potato, taro, and strawberry. Volatile and non-volatile metabolites produced by the strain are known to adversely affect the tested pathogens. FG106 showed clear antagonism against Alternaria alternata, Botrytis cinerea, Clavibacter michiganensis subsp. michiganensis, Phytophthora colocasiae, P. infestans, Rhizoctonia solani, and Xanthomonas euvesicatoria pv. perforans. FG106 produced proteases and lipases while also inducing high phosphate solubilization, producing siderophores, ammonia, indole acetic acid (IAA), and hydrogen cyanide (HCN) and forming biofilms that promote plant growth and facilitate biocontrol. Genome mining approaches showed that this strain harbors genes related to biocontrol and growth promotion. These results suggest that this bacterial strain provides good protection against pathogens of several agriculturally important plants via direct and indirect modes of action and could thus be a valuable bio-control agent.


2019 ◽  
Author(s):  
Adel Hadj Brahim ◽  
Mouna Jlidi ◽  
Lobna Daoud ◽  
Manel Ben-Ali ◽  
Asmahen Akremi ◽  
...  

Abstract Background The use of bioinoculants based on plant growth-promoting bacteria (PGPB) to promote plant growth under biotic and abiotic stresses is in full expansion. To our knowledge much work has not been, thus far, done on seed-biopriming of durum wheat for tolerance to biotic and abiotic stresses. In the present work, we report detailed account of the effectiveness a potent bacterial strain with proven plant growth-promoting ability and antimicrobial activity. The isolate was selected following screening of several bacterial strains isolated from halophytes that grow in a coastal saline soil in Tunisia for their role in enhancing durum wheat tolerance to both salinity stress and head blight disease.Results Accordingly, Bacillus strains MA9, MA14, MA17 and MA19 were found to have PGPB characteristics as they produced indole-3-acetic acid, siderophores and lytic enzymes, fixed free atmospheric nitrogen, and solubilized inorganic phosphate, in vitro . The in vivo study that involved in planta inoculation assays under control (25 mM NaCl) and stress (125 mM NaCl) conditions indicated that all PGPB strains significantly ( P < 0.05) increased the total plant length, dry weight, root area, seed weight, nitrogen, protein and total mineral content. On the other hand, strain MA17 reduced Fusarium Head Blight (FHB) disease incidence in wheat explants by 64.5%, showing that the strain has antifungal activity as was also displayed by in vitro inhibition study.Conclusions Both in vitro and in vivo studies showed that MA9, MA14 MA9, MA14, MA17 and MA19 strains were able to play the PGPB role. Yet, biopriming with Bacillus strain MA17 offered the highest bioprotection against FHB, plant growth promotion, and salinity tolerance. Hence, the MA17 strain should further be evaluated under field condition and formulated for commercial production. Besides, the strain could further be evaluated for its potential role in bioprotection and growth promotion of other crop plants. We believe, the strain has potential to significantly contribute to wheat production in the arid and semi-arid region, especially the salt affected Middle Eastern Region, besides its potential role in improving wheat production under biotic and abiotic stresses in other parts of the world.


1998 ◽  
Vol 44 (6) ◽  
pp. 528-536 ◽  
Author(s):  
V K Sharma ◽  
J Nowak

The potential utilization of a plant growth promoting rhizobacterium, Pseudomonas sp. strain PsJN, to enhance the resistance of tomato transplants to verticillium wilt was investigated. Plant growth and disease development were tested on the disease-susceptible cultivar Bonny Best after Verticillium dahliae infection of tissue culture plantlets bacterized in vitro (by co-culturing with the bacterium) and seedlings bacterized in vivo (after 3 weeks growth in the greenhouse). Significant differences in both disease suppression and plant growth were obtained between in vitro bacterized and nonbacterized (control) plants. The degree of protection afforded by in vitro bacterization depended on the inoculum density of V. dahliae; the best and worst protection occurred at the lowest (103 conidia ·mL-1) and highest (106 conidia ·mL-1) levels, respectively. In contrast, the in vivo bacterized tomatoes did not show plant growth promotion when compared to the nonbacterized control plants. When challenged with Verticillium, significant growth differences between in vivo bacterized plants (26.8% for shoot height) and nonbacterized controls were only seen at the 3rd week after inoculation. Compared with the in vitro inoculation, there was no delay in the verticillium wilt symptom expression, even at the lowest concentration of V. dahliae, by in vivo PsJN inoculation. These results suggest that endophytic colonization of tomato tissues is required for the Verticillium-resistance responses. Plant growth promotion preceeds the disease-resistance responses and may depend on the colonization thresholds and subsequent sensitization of hosts.Key words: Pseudomonas sp., plant growth promoting rhizobacterium, Verticillium dahliae, tomato, colonization, plant growth promotion, disease suppression.


Author(s):  
Seham M. Hamed ◽  
Eman S. Hagag ◽  
Neveen Abd El-Raouf

Abstract Background Cyanobacterium-based silver nanoparticles are considered not only as an efficient nano-nematicide but also as a bio-stimulant material for plant growth. They could be employed as a part of an integrated program for controlling some plant diseases. Results In this study, silver nanoparticles (Ag-NPs) were biosynthesized from aqueous extract of the cyanobacterium, Nostoc sp. PCC7524. Full characterization of the biosynthesized Ag-NPs was monitored by UV-vis spectroscopy, transmission electron microscopy, X-ray diffraction pattern, Zeta sizer, and Fourier transform infrared spectroscopy. In vitro assay against the root-knot nematode Meloidogyne javanica showed that Ag-NPs significantly decreased egg hatching of M. javanica at different applied concentrations (3, 6, 12, 25, and 50%, v/v). Fifty percent of Ag-NPs induced the highest reduction percent (94.66%). Moreover, Ag-NPs and AgNO3 significantly increased the percentages of larval mortality of the second-stage juveniles (J2) with concentration and time-dependent responses. Ag-NPs or AgNO3 at 2.4 ml/l, 24 h, completely inhibited the growth of J2 compared to 23% inhibition using aqueous cyanobacterial extract (ACE). In vivo effect of Ag-NPs on faba bean-infected plant under greenhouse conditions was achieved by treating soil with three different concentrations of 1, 2, and 3 ml/kg soil over two consecutive seasons. Ag-NPs significantly reduced root galling from 39.6 to 78.7% and J2 population in the soils from 32.2% to 86.7% in the 2018 season and from 21.9 to 78.1% and 40.0 to 81.0% in the 2019 season, respectively. Moreover, 3 ml/kg soil of Ag-NP treatment showed statistically comparable effects to that of vydate nematicide but with remarkable enhancement of faba bean growth parameters as compared to those of vydate or AgNO3 treatments in the two seasons. Conclusions The considerable in vitro and in vivo nematicidal potential of the cyanobacterium-based Ag-NPs, besides their bio-stimulant effect on plant growth, makes them feasible for the biological control of M. javanica.


2020 ◽  
Vol 13 (1) ◽  
pp. 124
Author(s):  
Fuad Ameen ◽  
Ali A. Al-Homaidan

Municipal organic wastes could be exploited as fertilizers, having been given the ability to suppress plant diseases by the inoculation of the waste with certain fungi in the composting process. Our aim was to develop a novel fertilizer using composting in combination with fungi associated with mangrove forests. Nine fungal species were isolated from a mangrove forest habitat and screened for their activity against five phytopathogenic fungi, their plant-growth promotion ability, and their phosphate solubilization ability. Two fungal isolates, Penicillium vinaceum and Eupenicillium hirayama, were inoculated into organic waste before the composting experiment. After 90 days, the physico-chemical properties of the compost (color, moisture, pH, C:N ratio and cation exchange capacity (CEC)) indicated the maturity of the compost. The C:N ratio decreased and the CEC value increased most in the compost with the inoculum of both mangrove fungi. The vegetable plants grown in the mangrove fungi-inoculated composts had a higher vigor index than those grown in the control compost. The seeds collected from the plants grown in the fungi-inoculated composts had higher disease defense ability than the seeds collected from the control compost. The results indicated that the properties of the fungi shown in vitro (antagonistic and plant-growth promotion) remained in the mature compost. The seeds of the plants acquired disease defense ability, which is a remarkable observation that is useful in sustainable agriculture.


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.


2020 ◽  
Vol 5 (02) ◽  
pp. 169-172
Author(s):  
Beenu Shastri ◽  
Rajesh Kumar ◽  
Ram Ji Lal

Sugarcane (Saccharum spp. hybrid) occupies an important position among the various commercial crops of India. It is the second most important agro-industrial crop, next only to cotton in the country. Among the various approaches, use of microorganisms is one of the crucial approaches for enhancement of crop production. In recent years, endophytic bacteria are gaining much attention towards the sustainable management of the agricultural crops. They not only help in the plant growth but also in alleviating the various stresses due to their multi-faceted role. In current study, two endophytic bacteria i.e. B. cereus (strain S8) and B. subtilis (strain S 17) isolated from the sugarcane root and stalk were evaluated for their plant growth promotion activity in vitro and as well as in vivo. Data indicated that the percentage germination was higher in B. cereus (S8) over B. subtilis (S 17) treated setts when observed after 45 days of planting. Various growth parameters viz., cane height, weight, number of shoots and internodes were also increased in the presence of endophytic bacterial inoculation over uninoculated control. Thus, it is concluded that sett treatment with indigenous endophytic bacteria (Bacillus spp.) can be exploited for enhancing cane yield and productivity in sugarcane culture.


2020 ◽  
Vol 11 (2) ◽  
pp. 1793-1797
Author(s):  
Madesh T ◽  
Abhinav Raj Ghosh ◽  
Krishna K L ◽  
Seema Mehdi ◽  
Nandini H S ◽  
...  

Momordica dioicaRoxb. (Cucurbitaceae) is commonly known as spiny gourd and traditionally used as astringent, febrifuge, antiseptic, anthelmintic, spermicidal and also used in bleeding piles, urinary infection and as a sedative. Studies indicate that it possesses antioxidant, hepatoprotective, antibacterial, anti-inflammatory, anti-lipid peroxidative, hypoglycaemic and analgesic properties. In this study, the anticancer efficacy of Cucurbitacins obtained from Momordica dioicaRoxb. (MDR) has been evaluated. Based on previous in-vitro studies performed, in-vivo studies were carried out on mice model.  Ehrlich ascites carcinoma (EAC) cells were inoculated into swiss albino mice intraperitoneally to form a liquid tumor and then treated with oral administration of 50, 100, 200mg/kg. Evaluation parameters involved the mean survival time (MST), body weight, hematological parameters, Percentage increase in life span were measured in normal control, EAC control and Cucurbitacintreated groups (n = 6). Treatment with Cucurbitacins enriched fraction has shown anti-tumor effects against liquid tumor as indicated by a significant (P < 0.05) reduction in body weight. Interestingly, the enriched bio fraction restored the altered hematological parameters of tumor-bearing animals and significantly increased their life span. These data indicate the cytotoxic potential effects of MDRon tumor cells opening new opportunities for further studies on the anti-cancer effects of this agent.


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