Susceptibility of endophyte-infected grasses to winter pathogens (snow molds)

2006 ◽  
Vol 84 (7) ◽  
pp. 1043-1051 ◽  
Author(s):  
Piippa R. Wäli ◽  
Marjo Helander ◽  
Oiva Nissinen ◽  
Kari Saikkonen

Neotyphodium endophytes are suggested to be mutualistic symbionts of grasses and regarded as potential biological plant protection agents. We examined the effects of the Neotyphodium endophyte of meadow ryegrass on snow molds in vitro with dual cultures of endophyte and Typhula ishikariensis , and on grass–snow mold interactions in vivo in a greenhouse and in a field experiment. In dual cultures, the endophytes formed an inhibition zone and retarded the growth of T. ishikariensis. In the field experiment, however, the endophyte-infected (E+) meadow ryegrasses were more susceptible to T. ishikariensis than the endophyte-free (E–) grasses. Endophyte infection increased the winter damage of grasses both in greenhouse and in field conditions. After winter, the growth of E+ grasses exceeded the growth of E– plants in the field experiment, indicating the marked tolerance of E+ grasses against winter damage. We detected differences in growth and pathogenesis between the different T. ishikariensis strains and found meadow ryegrass cultivar–endophyte status interaction in the growth of meadow ryegrasses, which highlight the effects of the genetic background of the participants on endophyte–grass–snow mold interactions.

2021 ◽  
Vol 19 ◽  
pp. 228080002198969
Author(s):  
Min-Xia Zhang ◽  
Wan-Yi Zhao ◽  
Qing-Qing Fang ◽  
Xiao-Feng Wang ◽  
Chun-Ye Chen ◽  
...  

The present study was designed to fabricate a new chitosan-collagen sponge (CCS) for potential wound dressing applications. CCS was fabricated by a 3.0% chitosan mixture with a 1.0% type I collagen (7:3(w/w)) through freeze-drying. Then the dressing was prepared to evaluate its properties through a series of tests. The new-made dressing demonstrated its safety toward NIH3T3 cells. Furthermore, the CCS showed the significant surround inhibition zone than empty controls inoculated by E. coli and S. aureus. Moreover, the moisture rates of CCS were increased more rapidly than the collagen and blank sponge groups. The results revealed that the CCS had the characteristics of nontoxicity, biocompatibility, good antibacterial activity, and water retention. We used a full-thickness excisional wound healing model to evaluate the in vivo efficacy of the new dressing. The results showed remarkable healing at 14th day post-operation compared with injuries treated with collagen only as a negative control in addition to chitosan only. Our results suggest that the chitosan-collagen wound dressing were identified as a new promising candidate for further wound application.


Plants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 963
Author(s):  
Maria C. Holeva ◽  
Athanasios Sklavounos ◽  
Rajendran Rajeswaran ◽  
Mikhail M. Pooggin ◽  
Andreas E. Voloudakis

Cucumber mosaic virus (CMV) is a destructive plant virus with worldwide distribution and the broadest host range of any known plant virus, as well as a model plant virus for understanding plant–virus interactions. Since the discovery of RNA interference (RNAi) as a major antiviral defense, RNAi-based technologies have been developed for plant protection against viral diseases. In plants and animals, a key trigger of RNAi is double-stranded RNA (dsRNA) processed by Dicer and Dicer-like (DCL) family proteins in small interfering RNAs (siRNAs). In the present study, dsRNAs for coat protein (CP) and 2b genes of CMV were produced in vitro and in vivo and applied onto tobacco plants representing a systemic solanaceous host as well as on a local host plant Chenopodium quinoa. Both dsRNA treatments protected plants from local and systemic infection with CMV, but not against infection with unrelated viruses, confirming sequence specificity of antiviral RNAi. Antiviral RNAi was effective when dsRNAs were applied simultaneously with or four days prior to CMV inoculation, but not four days post inoculation. In vivo-produced dsRNAs were more effective than the in vitro-produced; in treatments with in vivo dsRNAs, dsRNA-CP was more effective than dsRNA-2b, while the effects were opposite with in vitro dsRNAs. Illumina sequencing of small RNAs from in vivo dsRNA-CP treated and non-treated tobacco plants revealed that interference with CMV infection in systemic leaves coincides with strongly reduced accumulation of virus-derived 21- and 22-nucleotide (nt) siRNAs, likely generated by tobacco DCL4 and DCL2, respectively. While the 21-nt class of viral siRNAs was predominant in non-treated plants, 21-nt and 22-nt classes accumulated at almost equal (but low) levels in dsRNA treated plants, suggesting that dsRNA treatment may boost DCL2 activity. Taken together, our findings confirm the efficacy of topical application of dsRNA for plant protection against viruses and shed more light on the mechanism of antiviral RNAi.


2019 ◽  
Vol 10 (1) ◽  
pp. 24-30
Author(s):  
Ion Tarsardo Sianturi ◽  
Arief Prajitno ◽  
Ellana Sanoesi

Diseases is a problem in aquaculture, one of which is the diseases caused by the bacteriumP.fluorescens. Antibiotics and chemicals materials themselves can give the bacterium resistance and cause harm for the environment. One alternative that can be done is using a natural material, namely the rod of ciplukan (p. angulata). The purpose of this research was to explain the effect of P. angulata on the growth of p. fluorescens. The method which can be use is experimental method by using the research design of completely randomized design (ral) with 5 treatment and 2 control with 3 repetitions. The results showed that extract of P. angulata at various dose (6,67 ppt, 13,33 ppt, 19,99 ppt, 26,66 ppt and 33,33 ppt) exhibited anti-P. fluorescens activity with inhibition zone diameters in the range of (4,06±0,07 mm - 9,63±1,61 mm). Increashing extract dose lead to increased the inhibition zone. The extract dose of 33,33 ppt exhibited best anti-P. fluorescens activity in this research. The research results show that P. angulata is proven to be able to inhibit the P. fluorescens, but to prove the effectiveness of this material, an in vivo is required.


Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2393
Author(s):  
Xiuping Wang ◽  
Fei Peng ◽  
Caihong Cheng ◽  
Lina Chen ◽  
Xuejuan Shi ◽  
...  

Plant pathogens constantly develop resistance to antimicrobial agents, and this poses great challenges to plant protection. Therefore, there is a pressing need to search for new antimicrobials. The combined use of antimicrobial agents with different antifungal mechanisms has been recognized as a promising approach to manage plant diseases. Graphene oxide (GO) is a newly emerging and highly promising antimicrobial agent against various plant pathogens in agricultural science. In this study, the inhibitory activity of GO combined with fungicides (Mancozeb, Cyproconazol and Difenoconazole) against Fusarium graminearum was investigated in vivo and in vitro. The results revealed that the combination of GO and fungicides has significant synergistic inhibitory effects on the mycelial growth, mycelial biomass and spore germination of F. graminearum relative to single fungicides. The magnitude of synergy was found to depend on the ratio of GO and fungicide in the composite. In field tests, GO–fungicides could significantly reduce the disease incidence and disease severity, exhibiting a significantly improved control efficacy on F. graminearum. The strong synergistic activity of GO with existing fungicides demonstrates the great application potential of GO in pest management.


2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Zhiwen Hai ◽  
Yimeng Ren ◽  
Jiawen Hu ◽  
Huan Wang ◽  
Qi Qin ◽  
...  

Burn injury is a growing medical problem associated with public health, and few effective agents are available for treatment of this disease. In the present study, a burn injury rat model was developed and the accelerated effect of Aloe vera fermentation on burn injury healing was evaluated. Our results indicated that Aloe vera fermentation could markedly reduce the DPPH (56.12%), O2⋅− (93.5%), ⋅OH (76.12%), Fe2+ chelation (82%), and oxygen-reduction activity (0.28 μg/ml) and significantly inhibited the growth of pathogens S. typhimurium ATCC 13311 (inhibition zone diameter: 14 mm), S. enteritidis ATCC13076 (IZD: 13 mm), S. flexneri ATCC 12022 (IZD: 18 mm), E. coli 44102 (IZD: 10 mm), L. monocytogenes ATCC 19111 (IZD: 18 mm), S. dysenteriae 301 (IZD: 20 mm), S. aureus COWAN1 (IZD: 19 mm), and P. acnes ATCC 11827 (IZD: 25 mm) in vitro. The in vivo results indicated that Aloe vera fermentation produced more eosinophils and fibroblasts and less vessel proliferation compared with the model group on the 14th day, which had greatly accelerated burn injury healing via shedding of the scab and promoting hair growth. ELISA results indicated that Aloe vera fermentation had significantly reduced the production of proinflammatory factors TNF-α and IL-1β (p<0.05) and greatly enhanced the yield of anti-inflammatory factor IL-4 in animal serum (p<0.05). In addition, the high-throughput sequencing results indicated that Aloe vera fermentation obviously increased the percentage of Firmicutes (65.86% vs. 49.76%), while reducing the number of Bacteroidetes (27.60% vs. 45.15%) compared with the M group at the phylum level. At the genus level, Aloe vera fermentation increased the probiotic bacteria Lactobacillus (3.13% vs. 2.09%) and reduced the pathogens Prevotella (10.60% vs.18.24%) and Blautia (2.91% vs. 16.41%) compared with the M group. Therefore, we concluded that the use of Aloe vera fermentation significantly accelerates burn injury healing via reduction of the severity of inflammation and through modification of gut microbiota.


2016 ◽  
Vol 49 (1) ◽  
pp. 91-98 ◽  
Author(s):  
H. Barari

AbstractTrichodermaspp. have long been used as biological control agents against plant fungal diseases, but the mechanisms by which the fungi confer protection are not well understood. Our goal in this study was to isolate species ofTrichoderma, that exhibit high levels of biocontrol efficacy from natural environments and to investigate the mechanisms by which these strains confer plant protection. In this study, efficacy of the native isolates ofTrichodermaspecies to promote the growth and yield parameters of tomato and to manageFusariumwilt disease underin vitroandin vivoconditions were investigated. The dominant pathogen, which causesFusariumwilt of tomato, was isolated and identified asFusarium oxysporumf. sp.lycopersici(FOL). Twenty eight nativeTrichodermaantagonists were isolated from healthy tomato rhizosphere soil in different geographical regions of Mazandaran province, Iran. Underin vitroconditions, the results revealed thatTrichoderma harzianum, isolate N-8, was found to inhibit effectively the radial mycelial growth of the pathogen (by 68.22%). Under greenhouse conditions, the application ofT. harzianum(N-8) exhibited the least disease incidence (by 14.75%). Also, tomato plants treated withT. harzianum(N-8) isolate showed a significant stimulatory effect on plant height (by 70.13 cm) and the dry weight (by 265.42 g) of tomato plants, in comparison to untreated control (54.6 cm and 195.5 g). Therefore, the antagonistT. harzianum(N-8) is chosen to be the most promising bio-control agent forF. oxysporumf. sp.lycopersici. On the base of present study, the biocontrol agents of plant diseases might be exploited for sustainable disease management programs to save environmental risk.


Author(s):  
A. Kidanemariam ◽  
J. Gouws ◽  
M. Van Vuuren ◽  
B. Gummow

The in vitro activities of enrofloxacin, florfenicol, oxytetracycline and spiramycin were determined against field isolates of Mycoplasma mycoides mycoides large colony (MmmLC) by means of the broth microdilution technique. The minimum inhibitory concentrations (MICs) of these antimicrobial drugs were determined for a representative number of 10 isolates and 1 type strain. The susceptibility of Arcanobacterium pyogenes to enrofloxacin, oxytetracycline and tilmicosin was determined by means of an agar disk diffusion test. The MICs of enrofloxacin, florfenicol, oxytetracycline and spiramycin were within the ranges of 0.125-0.5, 1.0-2.0, 2.0-4.0 and 4.0-8.0 µg / m , respectively. This study has shown that resistance of MmmLC against enrofloxacin, florfenicol, oxytetracycline and spiramycin was negligible. All the field strains of A. pyogenes that were tested were susceptible to enrofloxacin, oxytetracycline and tilmicosin with mean inhibition zones of 30.6, 42.3 and 35.8mm, respectively. Although there is lack of data on in vivo efficacy and in vitro MIC or inhibition zone diameter breakpoints of these antimicrobial drugs for MmmLC, the MIC results indicate that these 4 classes of antimicrobial drugs should be effective in the treatment of ulcerative balanitis and vulvitis in sheep in South Africa.


2020 ◽  
Vol 14 (1) ◽  
pp. 113-119 ◽  
Author(s):  
Lisda Damayanti ◽  
Ida Ayu Evaangelina ◽  
Avi Laviana ◽  
Yetty Herdiyati ◽  
Dikdik Kurnia

Background: Caries and periodontitis are dental diseases caused by bacteria of S. sanguinis, S. mutans, and E. faecalis with three main etiological factors of the host, substrate, and time. Objective: This study proposed to investigate the antibacterial effects of Buah Merah (Pandanus conoideus Lam.) against oral bacteria of E.faecalis, S. mutans, and S. sanguinis. Materials and Methods: The Buah Merah was extracted with different solvents to yield n-hexane, ethyl acetate, methanol, and H2O extracts. The concentrations of single and mixture extracts were adjusted for antibacterial assay against bacteria of E. faecalis, S. mutans, and S. sanguinis strains through agar well diffusion assay with chlorhexidine, fosfomycin, and quercetin used as positive controls. Results: The ethyl acetate extract showed highest antibacterial activity against three oral bacterial of E. faecalis, S. mutans, and S. sanguinis with inhibition zones values of 9.3, 12.3, and 17.9 mm at 40%, respectively, together with their MIC and MBC values of 1250 & 2500, 0.312 & 0.625, and 0.312 & 0.625 ppm, respectively. For the formulation of extracts, combinations samples test gave various effects to different bacteria, with the best activity showed by methanol-ethyl acetate (M-Ea) extracts against S. mutans with an inhibition zone of 16.25 mm at 40 ppm. The strong and synergistic effect of methanol extract against S. mutans was supported by inhibition zones of the formulation of methanol extract-fosfomycin which showed an inhibition zone of 25.9 mm at 10 ppm. Conclusion: The extracts of Buah Merah demonstrated antibacterial activity against oral bacteria of E. faecalis, S. mutans, and S. sanguinis and gave important information for further in vivo clinical studies to determine the exact dosages and its effectiveness in practical application. These results prove the antimicrobial effects of Buah Merah extracts as alternative natural drugs with synergistic effects of active constituents.


2018 ◽  
Vol 5 (1) ◽  
pp. 39
Author(s):  
Samsudin Samsudin ◽  
Rita Harni ◽  
Efi Taufik

<p>Phytophthora palmivora<em> is a pathogen</em><em>ic fungus</em><em> that causes pod rot and stem cancer in cacao plant. This pathogen was difficult to control because it survives in the form of mycelium and chlamydospores in infected plant parts or in soil. </em>Trichoderma viride<em> is expected to inhibit the growth and development of this pathogen. The study aimed to determine the effectiveness of </em>T. viride<em> in inhibiting </em>P. palmivora<em> infection on cacao, conducted at Plant Protection Laboratory and Greenhouse of Indonesian Industrial and Beverage Crops Research Institute (IIBCRI), Sukabumi from March to December 2014. The </em>T. viride<em> TNU isolates used was purified and propagated in the laboratory. The </em>T. viride<em> inhibition against  </em>P. palmivora<em> growth and development was tested in vitro on potato dextrose agar medium (PDA) and in vivo on infected cacao pods and seedlings. The parameters observed were percentage of inhibition on PDA and the disease progression on infected pods and seedlings. The results showed that </em>T. viride<em> inhibited the growth of </em>P. palmivora<em> with inhibition percentage up to 68.60%, a strong antagonist for </em>P. palmivora<em> on PDA and reduced </em>P. palmivora<em> infection on seedlings in the greenhouse. Applications of </em>T. viride<em> 3 days before or after inoculation with </em>P. palmivora<em> was able to protect cacao seedlings in polybags, respectively by 60% and 45%. However, </em>T. viride<em> has not been able to hinder the development of pod rot disease on cacao.</em><em></em></p>


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