Seleção e Prospecção de Rizobactérias para o Controle Biológico do Mofo Branco em Espécies de Crotalaria spp

Author(s):  
Laís Mayara Melo Duré ◽  
Lara Rezek Rochaa ◽  
Ellen Juliete Damasceno Capurro ◽  
Bianca Obês Corrêa

O objetivo do trabalho foi isolar micro-organismos de diferentes nichos e avaliar a capacidade dos mesmos no controle de patógenos invitro (Sclerotinia sclerotiorum e Fusarium solani) e in vivo (S. sclerotiorum), além da promoção do crescimento de Crotalaria sp. Asamostras de solo foram pesadas e diluídas para obtenção dos micro-organismos. Nos testes in vitro, as colônias bacterianas, que apresentaram crescimento, foram submetidas ao confrontamento direto com os fungos fitopatogênicos. Para análise fisiológica das sementes de Crotalaria sp, as sementes foram distribuídas em caixas gerbox contendo papel filtro umedecido com água destilada e incubadas a 20-30 ºC por 10 dias. Também foram testadas a antibiose de escleródios em meio líquido. O delineamento usado foi DIC e os dados foram submetidos à análise de variância e comparados por Tukey a 0,5%. Além disso, foi realizada a patologia de sementes tratadas com as bactérias Fit-03 e Fit-04, além da microbiolização das sementes para avaliação da promoção do crescimento em casa de vegetação. Dos 51 isolados, seis foram capazes de produzir substâncias capazes de inibir o crescimento micelial do F. solani e três de S. sclerotiorum. Na avaliação da capacidade de controle de micro-organismos sobre as sementes das duas espécies de Crotalaria sp, Fit-03 e Fit-04 reduziram a incidência de fungos como Aspergillus e Penicillium. Pode-se afirmar que os isolados Fit-03 e Fit-04 apresentam potencial de uso no controle biológico do mofo branco em plantas de Crotalaria sp., bem como amplo espectro de ação.Palavras-chave: Antibiose. Sclerotinia sclerotiorum. Microbiolização de Sementes.AbstractThe objective was to isolate microorganisms of different niches and assess the ability of these in vitro control pathogens (Sclerotinia sclerotiorum and Fusarium solani) and in vivo (S. sclerotiorum) in addition to promoting the growth of Crotalaria sp. Soil samples were weighed and diluted to obtain the microorganisms. In in vitro tests the bacterial colonies that grew were subjected to direct confrontation with the pathogenic fungi. For physiological seed analysis Crotalaria sp. the seeds were distributed in gerbox boxes containing filter paper moistened with distilled water and incubated at 20-30 ° C for 10 days. Antibiosis sclerotia were also tested in liquid medium. The design used was DIC and the data were subjected to analysis of variance and compared by Tukey 0.5%. In addition, there was the seed pathology treated with the Fit-03 bacteria and Fit-04, in addition to microbiolization seeds for evaluation of growth promotion in greenhouse and also spraying the same in detached leaves of C. junceae and C. spectabillis and pathogen inoculation. After 51 isolates, six were able to produce substances capable of inhibiting the mycelial growth of F. solani and three S. sclerotiorum. In the evaluation of microorganisms control capability on the seeds of the two species of Crotalaria sp, Fit-Fit-03 and 04 reduced the incidence of fungi such as Aspergillus and Penicillium. It can be said that the Fit-03 isolated and Fit-04 have potential use in biological control of white mold in plant Crotalaria sp., as well as a broad spectrum of action.Keywords: Antibiosis. Sclerotinia sclerotiorum. Microbiolization seeds.

Author(s):  
Denise Pauletto Spanhol ◽  
José Rogerio De Oliveira ◽  
Bianca Obes Corrêa ◽  
Ismail Teodoro de Souza Junior ◽  
Marcelo Vedovatto ◽  
...  

O presente estudo teve como objetivo avaliar o potencial de bactérias, na promoção de crescimento, produção de compostos de defesa e no biocontrole do mofo branco em folhas destacadas de duas cultivares de soja. Os ensaios foram realizados com as bactérias antagonistas FIT09 (Bacillus cereus) e FIT62 (B. thuringensis), do fungo Sclerotinia sclerotiorum e com as cultivares de soja M6210 IPRO e Brasmax Garra IPRO. Nos ensaios in vivo foram avaliados a capacidade das bactérias na promoção do crescimento de plantas de soja e na constituição dos compostos secundários produzidos pelas plantas oriundas de sementes microbiolizadas com suspensões bacterianas. Além disso, os ensaios de biocontrole do mofo branco, foram realizados com folhas destacadas em estádio V3, as quais foram pulverizadas com as suspensões das bactérias FIT09 e FIT62. As bactérias FIT09 e FIT62 apresentaram compatibilidade com B. japonicum e no ensaio de biocontrole com folhas destacadas, verificou-se que a FIT 09 reduziu o diâmetro das lesões necróticas causadas por S. sclerotiorum em ambas cultivares de soja avaliadas em teste de folhas destacadas. No ensaio de promoção de crescimento, as bactérias aumentaram o poder germinativo na cultivar M6210 IPRO. Para a avaliação da análise fitoquímica, as bactérias auxiliaram positivamente na produção dos compostos relacionados ao sistema de defesa. Palavras-chave: Metabólitos Secundários. Fitoquímica. Sclerotinia sclerotiorum. Bacillus, Glycine max   Abstract The present study aimed to evaluate the potential of bacteria, in the promotion of growth, production of compounds of defens, and in the biocontrol of white mold in detached leaves of two soybean cultivars. The tests were performed with the antagonist bacteria FIT09 (Bacillus cereus) and FIT62 (B. thuringensis), with the fungus Sclerotinia sclerotiorum and with the soybean cultivars M6210 IPRO and Brasmax Garra IPRO. In vivo tests evaluated the capacity of bacteria to promote the growth of soybean plants and the constitution of secondary compounds produced by plants from microbiolized seeds with bacterial suspensions. In addition,  white mold biocontrol bioassays were carried out with detached leaves in stage V3 and they were sprayed with suspensions of the bacteria FIT09 and FIT62.The bacteria FIT09 and FIT62 were compatible with B. japonicum and in the biocontrol assay with detached leaves, it was found that FIT09 promoted superior control of 70% against the disease in both cultivars, however the disease did not manifest in the assay in plants. In the growth promotion test, the bacteria increased the germinative power in cultivar M6210 IPRO, for the assessment of fresh and dry mass there were no differences and for phytochemical analysis, the bacteria positively helped in the production of compounds related to the defense system.   Keywords: Secondary Metabolites. Phytochemistry, Sclerotinia sclerotiorum. Bacillus, Glycine max


2020 ◽  
Vol 73 (2) ◽  
Author(s):  
Hala Abdel Wahab ◽  
Ahmed Malek ◽  
Mohamed Ghobara

<em>Botrytis cinerea</em> and <em>Sclerotinia sclerotiorum</em> are necrotrophic fungi and are closely related pathogenic fungi that infect hundreds of plant species worldwide. In this study, the natural botryticidal/scleroticidal efficacy of some plant extracts, bioagents, and organic compounds known to possess antifungal activity was evaluated. Pathogenicity tests of the fungal molds showed virulence divergence, depending on the isolate and host plant. All <em>B. cinerea</em> isolates, except the BF isolate that infected only broad bean leaves, demonstrated ability to infect detached lettuce and broad bean leaves. Moreover, all <em>Sclerotinia sclerotiorum</em> isolates, except for SSP, demonstrated ability to infect the two plant species, whereas the SSB isolate did not cause any infection in broad bean leaves. The efficacies of <em>Moringa oleifera</em> (Mor), <em>Cinnamomum zeylanicum</em> (Cin), amino acid derivatives (Aad), <em>Trichoderma harzianum</em> (TH), <em>Cactus</em> spp. (Agr), and <em>Bacillus subtilis</em> (BS) were tested either in vitro or in vivo against the highly virulent isolates of the two pathogenic fungi. The efficacy of most potential biofungicides was consistent in vitro as well as in vivo, and the inhibitory efficacy of TH, BS, Cin, Mor, and Aad treatments was significantly high against <em>Botrytis cinerea</em> and <em>Sclerotinia sclerotiorum</em> in vitro and ranged from 62% to 100%, depending on the isolate. In addition, BS, Aad, TH, and Mor treatments had significant inhibitory effects ranging from 53% to 100% against most of the isolates on lettuce leaves. The Agr and Cin treatments exhibited low or no inhibitory effects against many isolates in vivo, and they reduced the mold infection caused by only BCC and SSB isolates. Most of the tested potential biofungicide treatments tended to reduce mold infections, and some of them, such as Cin, exhibited a higher inhibitory effect in vitro than the others. Real-time PCR was conducted for some symptomatic/asymptomatic samples, and the results showed either consistent molecular/symptomatic patterns or latency of <em>B. cinerea</em>. The results confirmed the suitability of the studied natural compounds as effective biofungicides, and they could be the best choice to safely control the most destructive fungal molds.


Biomolecules ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 582 ◽  
Author(s):  
Khamis Youssef ◽  
Sergio Ruffo Roberto ◽  
Admilton G. de Oliveira

Potassium bicarbonate (PB), calcium chelate (CCh), and sodium silicate (SSi) have been extensively used as antifungal generally recognized as safe (GRAS) compounds against plant pathogenic fungi. In this research, in in vitro tests, the radial growth, conidial germination, and germ tube elongation of Botrytis cinerea was completely inhibited at 0.3% of PB, SSi, and CCh. In in vivo tests, application of PB, SSi, and CCh completely inhibited the occurrence of gray mold incidence of inoculated ‘Italia’ grape berries at concentrations of 1.0, 0.8, and 0.8%, respectively. In order to investigate the detailed mechanisms by which salts exhibited antifungal activity, we analyzed their influence on morphological changes by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) and also on reactive species of oxygen (ROS), mitochondrial membrane potential (MMP), and adenosine triphosphate (ATP) content. Defects such as malformation and excessive septation were detected on salt-treated hyphae morphology observed by SEM. The internal structure of conidia treated or not with salt solutions was examined by TEM. In treated conidia, most of the conidia were affected and cellular vacuolization and cytoplasmic disorganization was observed. For ROS accumulation, a higher increase was observed in fluorescent conidia in presence of PB, SSi, and CCh by 75, 68, and 70% as compared to control, respectively. MMP was significantly decreased after salt application indicating a loss of mitochondria function. Also, luminescence showed that B. cinerea-conidia treated with salts contained less ATP than the untreated conidia. The results obtained herein are a step towards a comprehensive understanding of the mode of action by which salts act as antifungal agents against B. cinerea.


2018 ◽  
Vol 15 (1) ◽  
pp. 105-112 ◽  
Author(s):  
Phạm Đình Dũng ◽  
Nguyễn Tiến Thắng ◽  
Dương Hoa Xô ◽  
Lê Quang Luân

Chitosan was degraded by gamma rays irradiation method using 5% chitosan solution in 0.5% acetic acid with and without addition of 1% H2O2 for preparation of oligochitosan. The oligochitosan product with molecular weight (Mw) ~ 14.84 kDa prepared by radiation in combination with H2O2 treatment was used to fractionate into 5 different Mw fractions (F1: Mw < 1kDa, F2: Mw ~ 1-3 kDa, F3: Mw ~ 3-10 kDa, F4: Mw ~ 10-30 kDa và F5: Mw > 30 kDa) for testing its biological effects on red pepper plant (Capsicum frutescens L.). The obtained results showed that all separated fractions had the growth promotion effects on the increase of fresh biomass (9.9 - 56.3%) and chlorophyll content (20 - 92%) compared to those of the control one. In addition, the in vitro test of antifungal effect of separated fraction against C. capsici causing anthracnose on capsicum indicated that the fractions F3, F4 and F5 with Mw ≥ 3 kDa inhibited the growth of C. capsici colonies in a Potato Dextrose Agar (PDA) media at the concentration of 0.5%. While the the results from in vivo tests pointed out that the fractions F2, and F3 with the Mw in range of 1-10 kDa not only strongly stimulated the defense respose of tested plants to this pathogenic fungi causing anthracnose desease, but also the increased significantly gains of fruit biomass in 39 - 47%. Thus the oligochitosan fractions with Mw ~ 1-10 kDa are quite good products for both growth promotion efect as well as antifungal purpose for C. capsici causing anthracnose desease on capsicum.


1991 ◽  
Vol 66 (05) ◽  
pp. 609-613 ◽  
Author(s):  
I R MacGregor ◽  
J M Ferguson ◽  
L F McLaughlin ◽  
T Burnouf ◽  
C V Prowse

SummaryA non-stasis canine model of thrombogenicity has been used to evaluate batches of high purity factor IX concentrates from 4 manufacturers and a conventional prothrombin complex concentrate (PCC). Platelets, activated partial thromboplastin time (APTT), fibrinogen, fibrin(ogen) degradation products and fibrinopeptide A (FPA) were monitored before and after infusion of concentrate. Changes in FPA were found to be the most sensitive and reproducible indicator of thrombogenicity after infusion of batches of the PCC at doses of between 60 and 180 IU/kg, with a dose related delayed increase in FPA occurring. Total FPA generated after 100-120 IU/kg of 3 batches of PCC over the 3 h time course was 9-12 times that generated after albumin infusion. In contrast the amounts of FPA generated after 200 IU/kg of the 4 high purity factor IX products were in all cases similar to albumin infusion. It was noted that some batches of high purity concentrates had short NAPTTs indicating that current in vitro tests for potential thrombogenicity may be misleading in predicting the effects of these concentrates in vivo.


1980 ◽  
Vol 44 (02) ◽  
pp. 081-086 ◽  
Author(s):  
C V Prowse ◽  
A E Williams

SummaryThe thrombogenic effects of selected factor IX concentrates were evaluated in two rabbit models; the Wessler stasis model and a novel non-stasis model. Concentrates active in either the NAPTT or TGt50 in vitro tests of potential thrombogenicity, or both, caused thrombus formation in the Wessler technique and activation of the coagulation system in the non-stasis model. A concentrate with low activity in both in vitro tests did not have thrombogenic effects in vivo, at the chosen dose. Results in the non-stasis model suggested that the thrombogenic effects of factor IX concentrates may occur by at least two mechanisms. A concentrate prepared from platelet-rich plasma and a pyrogenic concentrate were also tested and found to have no thrombogenic effect in vivo.These studies justify the use of the NAPTT and TGt50 in vitro tests for the screening of factor IX concentrates prior to clinical use.


1963 ◽  
Vol 10 (01) ◽  
pp. 106-119 ◽  
Author(s):  
E Beck ◽  
R Schmutzler ◽  
F Duckert ◽  

SummaryInhibitor of kallikrein and trypsin (KI) extracted from bovine parotis was compared with ε-aminocaproic acid (EACA): both substances inhibit fibrinolysis induced with streptokinase. EACA is a strong inhibitor of fibrinolysis in concentrations higher than 0, 1 mg per ml plasma. The same amount and higher concentrations are not able to inhibit completely the proteolytic-side reactions of fibrinolysis (fibrinogenolysis, diminution of factor V, rise of fibrin-polymerization-inhibitors). KI inhibits well proteolysis of plasma components in concentrations higher than 2,5 units per ml plasma. Much higher amounts of KI are needed to inhibit fibrinolysis as demonstrated by our in vivo and in vitro tests.Combination of the two substances for clinical use is suggested. Therapeutic possibilities are discussed.


2019 ◽  
Vol 25 (36) ◽  
pp. 3872-3880 ◽  
Author(s):  
Marcel M. Bergmann ◽  
Jean-Christoph Caubet

Severe cutaneous adverse reactions (SCAR) are life-threatening conditions including acute generalized exanthematous pustulosis (AGEP), Stevens-Johnson Syndrome (SJS), toxic epidermal necrolysis (TEN) and drug reaction with eosinophilia and systemic symptoms (DRESS). Diagnosis of causative underlying drug hypersensitivity (DH) is mandatory due to the high morbidity and mortality upon re-exposure with the incriminated drug. If an underlying DH is suspected, in vivo test, including patch tests (PTs), delayed-reading intradermal tests (IDTs) and in vitro tests can be performed in selected patients for which the suspected culprit drug is mandatory, or in order to find a safe alternative treatment. Positivity of in vivo and in vitro tests in SCAR to drug varies depending on the type of reaction and the incriminated drugs. Due to the severe nature of these reactions, drug provocation test (DPT) is highly contraindicated in patients who experienced SCAR. Thus, sensitivity is based on positive test results in patients with a suggestive clinical history. Patch tests still remain the first-line diagnostic tests in the majority of patients with SCAR, followed, in case of negative results, by delayed-reading IDTs, with the exception of patients with bullous diseases where IDTs are still contra-indicated. In vitro tests have shown promising results in the diagnosis of SCAR to drug. Positivity is particularly high when the lymphocyte transformation test (LTT) is combined with cytokines and cytotoxic markers measurement (cyto-LTT), but this still has to be confirmed with larger studies. Due to the rarity of SCAR, large multi-center collaborative studies are needed to better study the sensitivity and specificity of in vivo and in vitro tests.


2016 ◽  
Vol 5 (03) ◽  
pp. 4927 ◽  
Author(s):  
Shubhi Srivastava ◽  
Paul A. K.

Plant associated microorganisms that colonize the upper and internal tissues of roots, stems, leaves and flowers of healthy plants without causing any visible harmful or negative effect on their host. Diversity of microbes have been extensively studied in a wide variety of vascular plants and shown to promote plant establishment, growth and development and impart resistance against pathogenic infections. Ferns and their associated microbes have also attracted the attention of the scientific communities as sources of novel bioactive secondary metabolites. The ferns and fern alleles, which are well adapted to diverse environmental conditions, produce various secondary metabolites such as flavonoids, steroids, alkaloids, phenols, triterpenoid compounds, variety of amino acids and fatty acids along with some unique metabolites as adaptive features and are traditionally used for human health and medicine. In this review attention has been focused to prepare a comprehensive account of ethnomedicinal properties of some common ferns and fern alleles. Association of bacteria and fungi in the rhizosphere, phyllosphere and endosphere of these medicinally important ferns and their interaction with the host plant has been emphasized keeping in view their possible biotechnological potentials and applications. The processes of host-microbe interaction leading to establishment and colonization of endophytes are less-well characterized in comparison to rhizospheric and phyllospheric microflora. However, the endophytes are possessing same characteristics as rhizospheric and phyllospheric to stimulate the in vivo synthesis as well as in vitro production of secondary metabolites with a wide range of biological activities such as plant growth promotion by production of phytohormones, siderophores, fixation of nitrogen, and phosphate solubilization. Synthesis of pharmaceutically important products such as anticancer compounds, antioxidants, antimicrobials, antiviral substances and hydrolytic enzymes could be some of the promising areas of research and commercial exploitation.


2019 ◽  
Vol 33 (9) ◽  
pp. 1285-1297 ◽  
Author(s):  
Cornelia Wiegand ◽  
Martin Abel ◽  
Uta-Christina Hipler ◽  
Peter Elsner ◽  
Michael Zieger ◽  
...  

Background Application of controlled in vitro techniques can be used as a screening tool for the development of new hemostatic agents allowing quantitative assessment of overall hemostatic potential. Materials and methods Several tests were selected to evaluate the efficacy of cotton gauze, collagen, and oxidized regenerated cellulose for enhancing blood clotting, coagulation, and platelet activation. Results Visual inspection of dressings after blood contact proved the formation of blood clots. Scanning electron microscopy demonstrated the adsorption of blood cells and plasma proteins. Significantly enhanced blood clot formation was observed for collagen together with β-thromboglobulin increase and platelet count reduction. Oxidized regenerated cellulose demonstrated slower clotting rates not yielding any thrombin generation; yet, led to significantly increased thrombin-anti-thrombin-III complex levels compared to the other dressings. As hemostyptica ought to function without triggering any adverse events, induction of hemolysis, instigation of inflammatory reactions, and initiation of the innate complement system were also tested. Here, cotton gauze provoked high PMN elastase and elevated SC5b-9 concentrations. Conclusions A range of tests for desired and undesired effects of materials need to be combined to gain some degree of predictability of the in vivo situation. Collagen-based dressings demonstrated the highest hemostyptic properties with lowest adverse reactions whereas gauze did not induce high coagulation activation but rather activated leukocytes and complement.


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