A new strain of Volutella citrinella with nematode predation and nematicidal activity, isolated from the cysts of potato cyst nematodes in China

Abstract Background Plant parasitic nematodes (PPNs) are responsible for causing many plant diseases and are extremely difficult to control at present. Currently, due to the negative effects of chemical agents on the environment and human health, the development of new biological pesticides has become an important part of plant nematode control. Nematophagous fungi refers to a class of fungi that kill plant nematodes. Notably, a large number of nematophagous fungi resources remain to be studied. The objective of our study was to use in vitro screening to identify nematophagous fungi and select strains that were highly active against nematodes, providing a primary research for the development and utilization of new nematophagous fungi. Results A new nematophagous fungal strain (GUCC2219) was isolated from cysts of possibly Globodera spp. and Heterodera spp., identified as Volutella citrinella. The hyphae of V. citrinella produced ring structures of variable size and exhibited predatory and nematicidal activity. The hyphal predation rates (in vitro) against three species of nematodes, Aphelenchoides besseyi, Bursaphelenchus xylophilus, and Ditylenchus destructor, averaged 59.45, 33.35, and 50.95%, respectively, while the fermentation broth produced by the fungus exhibited mortality rates of 100, 100, and 55.63%, respectively, after 72 h. Conclusion V. citrinella is a new strain with nematophagous properties, which are a novel discovery. At the same time, this is the first report of nematicidal and nematode predation activity in the genus Volutella.

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In vitro biological control of bovine parasitic nematodes by Arthrobotrys cladodes, Duddingtonia flagrans and Pochonia chlamydosporia under different temperature conditions

Journal of Helminthology ◽

10.1017/s0022149x20000796 ◽

2020 ◽

Vol 94 ◽

Author(s):

Ítalo Stoupa Vieira ◽

Isabela de Castro Oliveira ◽

Artur Kanadani Campos ◽

Jackson Victor de Araújo

Keyword(s):

Biological Control ◽

Mycelial Growth ◽

Nematophagous Fungi ◽

Nematicidal Activity ◽

Parasitic Nematodes ◽

Duddingtonia Flagrans ◽

Pochonia Chlamydosporia ◽

Fungal Strains ◽

Temperature Conditions

Abstract Variations in temperature can affect the development of nematophagous fungi, especially when they are used in the biological control of parasitic nematodes in the pastures where cattle are reared. The aim of this work was to evaluate the effects of temperature on the performance of nematophagous fungi in the biological control of bovine parasitic nematodes. The mycelial growth, chlamydospore production and nematicidal activity of Duddingtonia flagrans, Arthrobotrys cladodes and Pochonia chlamydosporia were evaluated at 15, 20, 25, 30 and 35°C. The fungal strains achieved mycelial growth, chlamydospore production and nematicidal activity on parasitic nematodes under all temperature conditions tested. The fungi showed higher growth at intermediate temperatures (20, 25 and 30°C) than at the extremes of 15 and 35°C. At 25 and 30°C, D. flagrans realized 96.8 and 94.5% nematicidal activity on bovine parasitic nematodes, respectively. Arthrobotrys cladodes effected nematicidal activity of 85.3 and 83.5%, at 20 and 25°C, respectively. At 20 and 30°C, P. chlamydosporia achieved nematicidal activity of 81.3 and 87.4%, respectively. The maximum chlamydospore production was reached at 20, 25 and 30°C for D. flagrans, at 20 and 25°C for A. cladodes and P. chlamydosporia. The results of this study demonstrated that the tested fungal strains of D. flagrans, A. cladodes and P. chlamydosporia, when used in the biological control of bovine parasitic nematodes, were not limited by in vitro temperature variations. Therefore, the use of these strains of fungi as biological control agents of parasitic nematodes is promising.

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Identification and Predictions Regarding the Biosynthesis Pathway of Polyene Macrolides Produced by Streptomyces roseoflavus Men-myco-93-63

Applied and Environmental Microbiology ◽

10.1128/aem.03157-20 ◽

2021 ◽

Vol 87 (10) ◽

Author(s):

Xing Han ◽

Jiao Wang ◽

Lianna Liu ◽

Fengying Shen ◽

Qingfang Meng ◽

...

Keyword(s):

Fermentation Broth ◽

Pathogenic Fungi ◽

Biosynthetic Gene Cluster ◽

Inhibitory Effect ◽

Plant Diseases ◽

Active Metabolites ◽

Content Type ◽

Polyene Macrolides ◽

Alternative Agent

ABSTRACT A group of polyene macrolides mainly composed of two constituents was isolated from the fermentation broth of Streptomyces roseoflavus Men-myco-93-63, which was isolated from soil where potato scabs were repressed naturally. One of these macrolides was roflamycoin, which was first reported in 1968, and the other was a novel compound named Men-myco-A, which had one methylene unit more than roflamycoin. Together, they were designated RM. This group of antibiotics exhibited broad-spectrum antifungal activities in vitro against 17 plant-pathogenic fungi, with 50% effective concentrations (EC50) of 2.05 to 7.09 μg/ml and 90% effective concentrations (EC90) of 4.32 to 54.45 μg/ml, which indicates their potential use in plant disease control. Furthermore, their biosynthetic gene cluster was identified, and the associated biosynthetic assembly line was proposed based on a module and domain analysis of polyketide synthases (PKSs), supported by findings from gene inactivation experiments. IMPORTANCE Streptomyces roseoflavus Men-myco-93-63 is a biocontrol strain that has been studied in our laboratory for many years and exhibits a good inhibitory effect in many crop diseases. Therefore, the identification of antimicrobial metabolites is necessary and our main objective. In this work, chemical, bioinformatic, and molecular biological methods were combined to identify the structures and biosynthesis of the active metabolites. This work provides a new alternative agent for the biological control of plant diseases and is helpful for improving both the properties and yield of the antibiotics via genetic engineering.

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Activation of hatching in diapaused and quiescent Globodera pallida

Parasitology ◽

10.1017/s0031182012001874 ◽

2012 ◽

Vol 140 (4) ◽

pp. 445-454 ◽

Cited By ~ 9

Author(s):

JUAN E. PALOMARES-RIUS ◽

JOHN T. JONES ◽

PETER J. COCK ◽

PABLO CASTILLO ◽

VIVIAN C. BLOK

Keyword(s):

Bursaphelenchus Xylophilus ◽

Globodera Pallida ◽

Parasitic Nematodes ◽

Plant Parasitic Nematodes ◽

Cyst Nematodes ◽

Term Survival ◽

C Elegans ◽

Dauer Formation ◽

Dorsal Gland

SUMMARYThe potato cyst nematodes (PCN) Globodera pallida and G. rostochiensis are major pests of potatoes. The G. pallida (and G. rostochiensis) life cycle includes both diapause and quiescent stages. Nematodes in dormancy (diapause or quiescent) are adapted for long-term survival and are more resistant to nematicides. This study analysed the mechanisms underlying diapause and quiescence. The effects of several compounds (8Br-cGMP, oxotremorine and atropine) on the activation of hatching were studied. The measurements of some morphometric parameters in diapaused and quiescent eggs after exposure to PRD revealed differences in dorsal gland length, subventral gland length and dorsal gland nucleolus. In addition, the expression of 2 effectors (IVg9 and cellulase) was not induced in diapaused eggs in water or PRD, while expression was slightly induced in quiescent eggs. Finally, we performed a comparative study to identify orthologues of C. elegans diapause related genes in plant-parasitic nematodes (G. pallida, Meloidogyne incognita, M. hapla and Bursaphelenchus xylophilus). This analysis suggested that it was not possible to identify G. pallida orthologues of the majority of C. elegans genes involved in the control of dauer formation. All these data suggest that G. pallida may use different mechanisms to C. elegans in regulating the survival stage.

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Nematicidal activity of the tropane alkaloids hyoscyamine and scopolamine against the root-knot nematode Meloidogyne incognita

Nematology ◽

10.1163/15685411-bja10074 ◽

2021 ◽

pp. 1-9

Author(s):

Djaafar Babaali ◽

Johannes Roeb ◽

Sabri Zaidat ◽

Bouchra Reguige ◽

Miloud Hammache ◽

...

Keyword(s):

Meloidogyne Incognita ◽

Tropane Alkaloids ◽

Datura Stramonium ◽

Nematicidal Activity ◽

Crop Damage ◽

Parasitic Nematodes ◽

Plant Parasitic Nematodes ◽

Root Knot Nematode ◽

Hyoscyamine And Scopolamine

Summary Alkaloids and alkaloid-producing plants have the potential to reduce crop damage by plant-parasitic nematodes. In a series of in vitro experiments, the nematicidal activity of the tropane alkaloids, hyoscyamine and scopolamine, and a mixture of both on the root-knot nematode, Meloidogyne incognita, was tested. Solutions of 16 mg of compound per ml of solvent were used in concentrations of 80-1280 μg ml−1 of water. Inactivity of second-stage juveniles of M. incognita increased with increasing concentration and exposure time. Lethal concentrations (LC50) after 120 min of exposure ranged from 182.4 μg ml−1 for scopolamine to 318.4 μg ml−1 for hyoscyamine and 332.8 μg ml−1 for the combination of both alkaloids. Similarly, the same concentrations of scopolamine inhibited hatching of M. incognita to a greater extent than hyoscyamine. In a glasshouse experiment, M. incognita was not able to penetrate the roots, induce galls and reproduce on Datura stramonium, D. innoxia and D. tatula. Results indicate that the tropane alkaloids hyoscyamine and scopolamine contained in Datura plants express a strong nematicidal activity against M. incognita and could possibly be used for an alternative and sustainable nematode management.

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In vitro stress selection of nematophagous fungi for biocontrol of parasitic nematodes in ruminants

Journal of Helminthology ◽

10.1017/s0022149x00010701 ◽

1991 ◽

Vol 65 (3) ◽

pp. 193-200 ◽

Cited By ~ 60

Author(s):

M. Larsen ◽

J. Wolstrup ◽

S. A. Henriksen ◽

C. Dackman ◽

J. Grønvold ◽

...

Keyword(s):

Hydrochloric Acid ◽

Acid Treatment ◽

Rumen Fluid ◽

Nematophagous Fungi ◽

Parasitic Nematodes ◽

Primary Stress ◽

Hydrochloric Acid Treatment ◽

Selection Step ◽

Predatory Capacity

ABSTRACTLaboratory experiments were designed to select nematophagous fungi that were able to survive in vitro conditions simulating passage through the gastro-intestinal tract of cattle. All of the tests were conducted at 39°C. In a primary stress selection step in diluted rumen fluid, 21 isolates were obtained. Each of the primary stress selected isolates was tested in synthetic saliva, rumen fluid simulating the activity in the rumen, rumen fluid followed by pepsin-hydrochloric acid treatment simulating the additional effect of ruminal and abomasal activity, pepsin-hydrochloric acid solution simulating conditions in the abomasum and finally in a trypsin solution as an example of enzyme activity in the gut. The effect of the rumen fluid alone, or rumen fluid followed by pepsin-hydrochloric acid treatment, were responsible for the reduction in surviving fungal isolates. Only six of thirteen isolates belonging to the genus Arthrobotrys survived while seven of eight isolates of the genus Duddingtonia survived. Fourteen isolates were tested for their predatory capacity in a dung pat bioassay. Fungi of the genera Arthrobotrys and Duddingtonia reduced the development of Ostertagia ostertagi third stage larvae by approximately 75% and 96% respectively compared to the number of larvae that developed from fungus-free control pats.

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Nematicidal Evaluation and Active Compounds Isolation of Aspergillus japonicus ZW1 against Root-Knot Nematodes Meloidogyne incognita

Agronomy ◽

10.3390/agronomy10091222 ◽

2020 ◽

Vol 10 (9) ◽

pp. 1222

Author(s):

Qiong He ◽

Dongya Wang ◽

Bingxue Li ◽

Ambreen Maqsood ◽

Haiyan Wu

Keyword(s):

Meloidogyne Incognita ◽

Active Compound ◽

Fermentation Broth ◽

The Body ◽

Nematicidal Activity ◽

Parasitic Nematodes ◽

Root Knot Nematode ◽

Egg Hatching ◽

Liquid Chromatograph ◽

Aspergillus Japonicus

The root-knot nematode is one of the most damaging plant-parasitic nematodes worldwide, and the ecofriendly alternative approach of biological control has been used to suppress nematode populations. Here the nematicidal activity of Aspergillus japonicus ZW1 fermentation filtrate against Meloidogyne incognita was evaluated in vitro and in greenhouse, and the effects of A. japonicus ZW1 fermentation filtrate on seed germination and the active compound of A. japonicus ZW1 fermentation filtrate were determined. The 2-week fermentation filtrate (2-WF) of A. japonicus ZW1 exhibited markedly inhibitory effects on egg hatching, and 5% 2-WF showed potential nematicidal activities on second-stage juveniles (J2s); the mortality of J2s was 100% after 24 h exposure. The internal contents of nematodes were degraded and remarkable protruded wrinkles were present on the body surface of J2s. The nematicidal activity of the fermentation was stable after boiling and was not affected by storage time. A germination assay revealed that 2-WF did not have a negative effect on the viability and germination of corn, wheat, rice, cowpeas, cucumbers, soybeans, or tomato seeds. The pot-grown study confirmed that a 20% fermentation broth solution significantly reduced root galls and egg numbers on tomatoes, and decreased galls and eggs by 47.3% and 51.8% respectively, over Czapek medium and water controls. The active compound from the A. japonicus ZW1 fermentation filtrate was isolated and identified as 1,5-Dimethyl Citrate hydrochloride ester on the basis of nuclear magnetic resonance (NMR) and LC-MS (liquid chromatograph-mass spectrometer) techniques. Thus, fermentation of A. japonicus ZW1 could be considered a potential new biological nematicide for the control of M. incognita.

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Alcaligenes faecalis ZD02, a Novel Nematicidal Bacterium with an Extracellular Serine Protease Virulence Factor

Applied and Environmental Microbiology ◽

10.1128/aem.03444-15 ◽

2016 ◽

Vol 82 (7) ◽

pp. 2112-2120 ◽

Cited By ~ 9

Author(s):

Shouyong Ju ◽

Jian Lin ◽

Jinshui Zheng ◽

Shaoying Wang ◽

Hongying Zhou ◽

...

Keyword(s):

Serine Protease ◽

Virulence Factor ◽

Fermentation Broth ◽

Alcaligenes Faecalis ◽

Nematicidal Activity ◽

Parasitic Nematodes ◽

Content Type ◽

C Elegans ◽

Almost All ◽

Extracellular Serine Protease

ABSTRACTRoot knot nematodes (RKNs) are the world's most damaging plant-parasitic nematodes (PPNs), and they can infect almost all crops. At present, harmful chemical nematicides are applied to control RKNs. Using microbial nematicides has been proposed as a better management strategy than chemical control. In this study, we describe a novel nematicidal bacterium namedAlcaligenes faecalisZD02.A. faecalisZD02 was isolated fromCaenorhabditis eleganscadavers and has nematostatic and nematicidal activity, as confirmed byC. elegansgrowth assay and life span assay. In addition,A. faecalisZD02 fermentation broth showed toxicity againstC. elegansandMeloidogyne incognita. To identify the nematicidal virulence factor, the genome of strain ZD02 was sequenced. By comparing all of the predicted proteins of strain ZD02 to reported nematicidal virulence factors, we determined that an extracellular serine protease (Esp) has potential to be a nematicidal virulence factor, which was confirmed by bioassay onC. elegansandM. incognita. UsingC. elegansas the target model, we found that bothA. faecalisZD02 and the virulence factor Esp can damage the intestines ofC. elegans. The discovery thatA. faecalisZD02 has nematicidal activity provides a novel bacterial resource for the control of RKNs.

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Enhanced production of pinosylvin stilbene with aging of Pinus strobus callus and nematicidal activity of callus extracts against pinewood nematodes

Scientific Reports ◽

10.1038/s41598-022-04843-6 ◽

2022 ◽

Vol 12 (1) ◽

Author(s):

Hyo Bin Koo ◽

Hwan-Su Hwang ◽

Jung Yeon Han ◽

Eun Ju Cheong ◽

Yong-Soo Kwon ◽

...

Keyword(s):

Pinus Strobus ◽

Monomethyl Ether ◽

Bursaphelenchus Xylophilus ◽

Nematicidal Activity ◽

Zygotic Embryos ◽

Enhanced Production ◽

Pinewood Nematodes ◽

Ethanolic Extraction ◽

Ethanol Extracts

AbstractPinosylvin stilbenes are phenolic compounds mainly occurring in the Pinaceae family. We previously reported that the accumulation of two pinosylvin stilbene compounds, dihydropinosylvin methyl ether (DPME) and pinosylvin monomethyl ether (PME), in Pinus strobus trees was highly enhanced by infection with pine wood nematodes (PWNs: Bursaphelenchus xylophilus), and these two compounds showed strong nematicidal activity against PWNs. In this work, we established a system of pinosylvin stilbene (DPME and PME) production via the in vitro culture of P. strobus calli, and we examined the nematicidal activity of callus extracts. Calli were induced from the culture of mature zygotic embryos of P. strobus. Optimized growth of calli was obtained in 1/2 Litvay medium with 1.0 mg/L 2,4-D and 0.5 mg/L BA. DPME and PME accumulation did not occur in nonaged (one-month-old) calli but increased greatly with prolonged callus culture. The concentrations of DPME and PME in three-month-old dark-brown calli were 6.4 mg/g DW and 0.28 mg/g DW, respectively. The effect of methyl jasmonate treatment on the accumulation of DPME and PME was evaluated in cell suspension culture of P. strobus. However, the treatment appeared to show slight increase of DPME accumulation compared to callus browning. A test solution prepared from crude ethanol extracts from aged calli (three months old) containing 120 µg/ml DPME and 5.16 µg/ml PME treated with PWNs resulted in 100% immobilization of the adult PWNs and 66.7% immobilization of the juvenile PWNs within 24 h. However, nonaged callus extracts did not show any nematicidal activity against juvenile PWNs and showed less than 20% nematicidal activity against adult PWNs. These results indicate that pinosylvin stilbenes can be effectively produced by prolonged culture of P. strobus calli, can be isolated using simple ethanolic extraction, and are applicable as beneficial eco-friendly compounds with nematicidal activity against PWNs.

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Nematicidal Activity of 5-Hydroxymethyl-2-furoic Acid against Plant-Parasitic Nematodes

Zeitschrift für Naturforschung C ◽

10.1515/znc-2007-3-413 ◽

2007 ◽

Vol 62 (3-4) ◽

pp. 234-238 ◽

Cited By ~ 7

Author(s):

Yasuo Kimura ◽

Satoko Tani ◽

Asami Hayashi ◽

Kouhei Ohtani ◽

Shozo Fujioka ◽

...

Keyword(s):

Bursaphelenchus Xylophilus ◽

Nematicidal Activity ◽

Parasitic Nematodes ◽

Pratylenchus Penetrans ◽

Plant Parasitic Nematodes ◽

Nematode Caenorhabditis Elegans ◽

Free Living ◽

Furoic Acid ◽

Free Living Nematode ◽

Aspergillus Sp

Abstract A nematicide, 5-hydroxymethyl-2-furoic acid (1), was isolated from cultures of the fungus Aspergillus sp. and its structure was identified by spectroscopic analysis. Compound 1 showed effective nematicidal activities against the pine wood nematode Bursaphelenchus xylophilus and the free-living nematode Caenorhabditis elegans without inhibitory activity against plant growth, but 1 did not show any effective nematicidal activity against Pratylenchus penetrans.

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In vitro nematicidal activity of a terrestrial cyanobacterium, Synechococcus nidulans, towards plant-parasitic nematodes

Nematology ◽

10.1163/138855411x578879 ◽

2012 ◽

Vol 14 (1) ◽

pp. 85-92 ◽

Cited By ~ 2

Author(s):

Prasanna Holajjer ◽

Anju Kamra ◽

Hari S. Gaur ◽

Dolly Wattal Dhar

Keyword(s):

Nematicidal Activity ◽

Parasitic Nematodes ◽

Plant Parasitic Nematodes ◽

Rotylenchulus Reniformis ◽

Second Stage ◽

Significant Difference ◽

Control Water ◽

Plant Parasitic ◽

Heterodera Cajani

The nematicidal activity of a terrestrial cyanobacterium, Synechococcus nidulans, was investigated. Extracts of S. nidulans cultures collected at weekly intervals for 5 weeks were sonicated and tested against second-stage juveniles (J2) of Meloidogyne incognita. Extracts of 2-week-old cultures caused the maximum immobility (94.2%) and mortality (29.3%) of J2, compared with controls (medium and water). This extract was tested in vitro against infective stages and hatch of M. graminicola, Heterodera cajani, H. avenae and Rotylenchulus reniformis. Extracts of sonicated S. nidulans caused a mean immobility in the range of 91.3-98.4% in infective stages of the nematodes, with no significant difference with an increase in exposure time from 24 to 72 h. The greatest mean percentage mortality was observed in M. graminicola (31.5%) followed by M. incognita (29.3%), H. avenae (20.9%), and R. reniformis and H. cajani (both 17.4%) with a significant increase with the period of exposure from 24 to 72 h. No significant differences in mortality were observed between M. graminicola and M. incognita and between H. avenae and H. cajani. The percentage hatch inhibition over control (water) was greatest in M. incognita (94.2%), followed by H. avenae (91.6%), H. cajani (72.3%) and M. graminicola (70.6%), and least in R. reniformis (58.6%).

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