scholarly journals A Novel Antifungal Actinomycete Streptomyces sp. Strain H3-2 Effectively Controls Banana Fusarium Wilt

2021 ◽  
Vol 12 ◽  
Author(s):  
Niexia Zou ◽  
Dengbo Zhou ◽  
Yinglong Chen ◽  
Ping Lin ◽  
Yufeng Chen ◽  
...  
Keyword(s):  
Antifungal Activity ◽  
Fusarium Wilt ◽  
Fermentation Broth ◽  
Membrane Integrity ◽  
Wilt Disease ◽  
Cell Membrane Integrity ◽  
Fusarium Wilt Disease ◽  
Fungal Phytopathogens ◽  
Environmentally Sound

Banana Fusarium wilt disease caused by Fusarium oxyspoum f. sp. cubense (Foc) seriously threatens the banana industry. Foc tropical race 4 (Foc TR4) can infect almost all banana cultivars. Compared with traditional physical and chemical practices, biocontrol strategy using beneficial microbes is considered as an environmentally sound option to manage fungal disease. In this study, a strain, H3-2, isolated from a non-infected banana orchard, exhibited high antifungal activity against Foc TR4. According to its morphological, physiological, and biochemical characteristics, the strain H3-2 was identified as Streptomyces sp. and convinced by the polymorphic phylogenic analysis of 16S rRNA sequences. Extracts of the strain H3-2 suppressed the growth and spore germination of Foc TR4 in vitro by destroying cell membrane integrity and mycelial ultrastructure. Notably, the strain and its extracts showed broad-spectrum antifungal activity against the selected seven fungal phytopathogens. Fourteen chemical compounds in the extracts were identified by gas chromatography–mass spectrometer (GC-MS), primarily phenolic compounds. Additional pot inoculation experiment demonstrated that the fermentation broth of the strain H3-2 promoted the growth of banana seedlings by efficiently inhibiting the spread of banana Fusarium wilt disease. This study demonstrated the potential application of the novel Streptomyces sp. H3-2 for the management of banana Fusarium wilt.

scholarly journals Newly Isolated Streptomyces sp. JBS5-6 as a Potential Biocontrol Agent to Control Banana Fusarium Wilt: Genome Sequencing and Secondary Metabolite Cluster Profiles

2020 ◽  
Vol 11 ◽  
Author(s):  
Tao Jing ◽  
Dengbo Zhou ◽  
Miaoyi Zhang ◽  
Tianyan Yun ◽  
Dengfeng Qi ◽  
...  
Keyword(s):  
Fusarium Wilt ◽  
Complete Genome ◽  
Biocontrol Agent ◽  
Fermentation Broth ◽  
Membrane Integrity ◽  
Gene Clusters ◽  
Wilt Disease ◽  
Gas Chromatography Mass Spectrometry ◽  
Fusarium Wilt Disease ◽  
Potential Biocontrol Agent

Banana is a key staple food and fruit in countries all over the world. However, the development of the global banana industry is seriously threatened by Fusarium wilt disease, which is caused by Fusarium oxysporum f. sp. cubense (Foc). In particular, Foc tropical race 4 (Foc TR4) could infect more than 80% of global banana and plantain crops. Until now, there were no commercial chemicals or resistant cultivars available to control the disease. Biological control using actinomycetes is considered a promising strategy. In this study, 88 actinomycetes were isolated from a banana orchard without symptoms of Fusarium wilt disease for more than 10 years. An actinobacterial strain labeled as JBS5-6 has exhibited strong antifungal activities against Foc TR4 and other selected 10 phytopathogenic fungi. Based on phenotypic and biochemical traits as well as complete genome analysis, strain JBS5-6 was assigned to Streptomyces violaceusniger. Extracts of the strain inhibited the mycelial growth and spore germination of Foc TR4 by destroying membrane integrity and the ultrastructure of cells. The complete genome of strain JBS5-6 was sequenced and revealed a number of key function gene clusters that contribute to the biosynthesis of active secondary metabolites. Sixteen chemical compounds were further identified by gas chromatography-mass spectrometry (GC-MS). 5-hydroxymethyl-2-furancarboxaldehyde was one of the dominant components in strain JBS5-6 extracts. Moreover, fermentation broth of strain JBS5-6 significantly reduced the disease index of banana seedlings by inhibiting the infection of Foc TR4 in a pot experiment. Hence, strain JBS5-6 is a potential biocontrol agent for the management of disease and the exploitation of biofertilizer.

Genome-wide screening antifungal genes in Streptomyces griseus S4-7, a Fusarium wilt disease suppressive microbial agent

2019 ◽  
Vol 366 (12) ◽  
Author(s):  
Sung Won Hong ◽  
Da-Ran Kim ◽  
Youn Sang Kwon ◽  
Youn-Sig Kwak
Keyword(s):  
Antifungal Activity ◽  
Secondary Metabolites ◽  
Fusarium Wilt ◽  
Streptomyces Griseus ◽  
Wilt Disease ◽  
Inverse Pcr ◽  
Genus Streptomyces ◽  
Fusarium Wilt Disease ◽  
Genome Wide ◽  
A Genome

ABSTRACT Streptomyces is a widely studied bacterial genus, particularly with regard to secondary metabolites and antibiotics production. Streptomyces griseus S4–7 was isolated from a strawberry Fusarium wilt disease suppressive soil, and its biological control ability has been well established. However, the antifungal mechanism of strain S4–7 is not yet fully understood at the molecular and biochemical level. Therefore, in this study we created a random mutant library for strain S4–7 with the Tn5 transposon element to investigate antifungal traits on a genome-wide scale. In total 4646 individual mutant strains were created and 13 mutants were selected based on loss of antifungal activity. The knockout genes were identified as electron transfer oxidoreductase (eto),sigma factor-70(sig70) and nrps by Inverse PCR (I-PCR). eto regulates the geranylgeranyl reductase gene, which is involved in terpenoid-quinone biosynthesis, an important factor in cell fitness. In the △eto strain, expression of wbl, a master regulator of the production of secondary metabolites, was significantly reduced. sig70 is responsible for the cell differentiation sensing mechanism in genus Streptomyces. △nrps showed decreased production of hybrid peptide-polyketide siderophores. These results suggest that S. griseus S4–7 may have various antifungal mechanisms, and each mechanism is essential to maximal antifungal activity.

scholarly journals Phenolic Acid-Degrading Consortia Increase Fusarium Wilt Disease Resistance of Chrysanthemum

Agronomy ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 385
Author(s):  
Cheng Zhou ◽  
Zhongyou Ma ◽  
Xiaoming Lu ◽  
Lin Zhu ◽  
Jianfei Wang
Keyword(s):  
Microbial Community ◽  
Fusarium Wilt ◽  
Wilt Disease ◽  
Disease Suppression ◽  
Suppressive Soil ◽  
Soil Borne Pathogens ◽  
Fusarium Wilt Disease ◽  
Pseudomonas Species ◽  
Conducive Soil

Soil microbial community changes imposed by the cumulative effects of root-secreted phenolic acids (PAs) promote soil-borne pathogen establishment and invasion under monoculture systems, but the disease-suppressive soil often exhibits less soil-borne pathogens compared with the conducive soil. So far, it remains poorly understood whether soil disease suppressiveness is associated with the alleviated negative effects of PAs, involving microbial degradation. Here, the long-term monoculture particularly shaped the rhizosphere microbial community, for example by the enrichment of beneficial Pseudomonas species in the suppressive soil and thus enhanced disease-suppressive capacity, however this was not observed for the conducive soil. In vitro PA-degradation assays revealed that the antagonistic Pseudomonas species, together with the Xanthomonas and Rhizobium species, significantly increased the efficiency of PA degradation compared to single species, at least partially explaining how the suppressive soil accumulated lower PA levels than the conducive soil. Pot experiments further showed that this consortium harboring the antagonistic Pseudomonas species can not only lower PA accumulation in the 15-year conducive soils, but also confer stronger Fusarium wilt disease suppression compared with a single inoculum with the antagonistic bacteria. Our findings demonstrated that understanding microbial community functions, beyond the single direct antagonism, facilitated the construction of active consortia for preventing soil-borne pathogens under intensive monoculture.

scholarly journals Uji Ketahanan Planlet Anggrek Bulan (Phalaenopsis amabilis (L.) Bl.) Hasil Seleksi dengan Asam Salisilat Terhadap Fusarium oxysporum Secara In Vitro

2017 ◽  
Vol 17 (2) ◽  
Author(s):  
Ria Aulia Noviantia ◽  
Endang Nurcahyani ◽  
Martha Lulus Lande
Keyword(s):  
Salicylic Acid ◽  
Fusarium Oxysporum ◽  
Fusarium Wilt ◽  
In Vitro Selection ◽  
Wilt Disease ◽  
Fusarium Wilt Disease ◽  
Selection For

Phalaenopsis amabilis cultivated have many constraints such as the appearance of fusarium wilt disease caused by Fusarium oxysporum. Plantlet P.amabilis which resistant to F. Oxysporum was selected in the solid Vacin and Went (VW) medium was added with salicylic acid at concentrations of 65 ppm, 75 ppm, and 85 ppm, compared with controls (0 ppm). The goals of the research were to study and determine of: 1) The SA concentration of planlet P. amabilis selection tolerant; 2) The proper concentration of AS during in vitro selection for suppressing the Fo. The research was carried out in December 2015 to February 2016 in the Botany Laboratory (in vitro research room), Departement of Biology, Faculty of MIPA, Lampung University. The result showed that: 1) The SA tolerant concentration for plantlet selection with P. amabilis was between 65 ppm - 85 ppm. 2) The 85 ppm of SA was effective for suppressing the Fo compared to 65 ppm and 75 ppm. Keywords: Phalaenopsis amabilis, salicylic acid, Fusarium oxysporum, In vitro, Resistance.

scholarly journals In Vitro Induced Resistance of Fusarium Wilt Disease (Fusarium oxysporum f.sp. cepae) by Salicylic Acid in Shallot CV ‘Bima Brebes’

2017 ◽  
Vol 2 (1) ◽  
pp. 001
Author(s):  
Khusnul Khotimah ◽  
Endang Sulistyaningsih ◽  
Arif Wibowo
Keyword(s):  
Salicylic Acid ◽  
Fusarium Oxysporum ◽  
Induced Resistance ◽  
Fusarium Wilt ◽  
Fusaric Acid ◽  
Wilt Disease ◽  
Resistance Response ◽  
Toxic Symptom ◽  
Fusarium Wilt Disease

Fusarium wilt caused by Fusarium oxysporum f.sp.cepae (Foc) is one of the most important diseases of onion in Indonesia. Induced resistance was one of the effective techniques to acquire resistance to fusarium wilt in shallot. Salicylic acid (SA) had been inferred to be in endogenous signal in the systemic acquired resistance response of plants. This research aimed to study the effect of exogenously added SA to resistance in shallot callus cv ‘Bima Brebes’ to fusarium wilt disease in vitro; and to determine the effective concentration of SA to induce resistance. A group of shallot callus was grown in MS medium containing varying SA concentration (0, 15, 20 and 25 ppm) in vitro for 2 weeks. Then, the callus were treated with toxin of Fusarium oxysporum, namely fusaric acid, to have observe the resistance response. In vitro selection was done twice in different fusaric acid concentration. Application of exogenous SA at all concentration did not suppres time of appearance of disease symptom yet. Toxic symptom in the callus was shown by the browning or blackening (off) of callus. Salicylic acid at concentration of 20 ppm effectively reduced the toxic symptom up to 16.66% and supported callus regeneration better than the concentration of 15 ppm and 25 ppm. The number of resistant callus regenerated was 66.67% at pretreatment of 20 ppm of SA.

scholarly journals Preparation of the oligochitosan-silver nanoparticles with a potential application as an antigungal fertilizer against Fusarium oxysporum causing fusarium wilt disease on tomato

2018 ◽  
Vol 15 (1) ◽  
pp. 141-149
Author(s):  
Nguyễn Thanh Vũ ◽  
Huỳnh Quyền ◽  
Dương Hoa Xô ◽  
Lê Quang Luân
Keyword(s):  
Silver Nanoparticles ◽  
Antifungal Activity ◽  
Fusarium Oxysporum ◽  
Fusarium Wilt ◽  
Foliar Application ◽  
Growth Promotion ◽  
Wilt Disease ◽  
In Vitro Test ◽  
Tomato Plants ◽  
Fusarium Wilt Disease

Chitosan with molecular weight (Mw) approx. 573,2 kDa and deacetylation degree about 80% was irradiated by gamma rays at swollen state in the present of 1 - 3% hydrogen peroxide for degradation to prepare low Mw products. The solution of 5% low Mw chitosan in 0.5% acetic acid was further irradiated for induction of oligochitosan. The obtained results indicated that the foliar application by 100 ppm oligochitosan with Mw ~ 19.5 kDa prepared by 4kGy-irradiation of the low Mw chitosan with Mw ~ 48.4 kDa had a strongly growth promotion effect on tomato plants after 30 days cultivation. The oligochitosan silver nanoparticles (AgNPs) was also synthesized by gamma irradiation of solution contained 5% low Mw chitosan and 1 mM silver nitrate in order to prepared antifungal fertilizer for tomato plants. The results on in vitro test for the antifungal activity oligochitosan AgNPs against Fusarium oxysporum causing Fusarium wilt disease pointed out that the addition of this product into cultivated media inhibited strongly the growth of the Fusarium oxysporum pathogen fungus on carrot agar media. The antifungal efficiency values were found from 50.5 to 94.9% by the supplementions of silver concentrations from 20 to 30 ppm, respectively. The supplementation with a silver concentration of 40 ppm inhibited completely the growth of F. oxysporum on the cultivated media. Thus the oligochitosan AgNPs product had not only the growth promotion activity for tomato, but also high antifungal activity against F. oxysporum. This product is promising to be used as an antifungal fertilizer for tomato with safety and efficiency.

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