scholarly journals Superabsorbent Polymer Seed Coating Reduces Leaching of Fungicide but Does Not Alter Their Effectiveness in Suppressing Pathogen Infestation

Polymers ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 76
Author(s):  
Marcela Gubišová ◽  
Martina Hudcovicová ◽  
Pavel Matušinský ◽  
Katarína Ondreičková ◽  
Lenka Klčová ◽  
...  
Keyword(s):  
Plant Protection ◽  
Fusarium Culmorum ◽  
Early Growth ◽  
Seed Coating ◽  
Mycelium Growth ◽  
Maize Seeds ◽  
Early Growth Phase ◽  
Pathogen Dna ◽  
Juvenile Plants

Superabsorbent polymers (SAPs) applied to soil have been recognized as water reservoirs that allow plants to cope with periods of drought. Their application as a seed coat makes water available directly to the seeds during their germination and early growth phase, but on the other hand, it can affect the efficiency of plant protection substances used in seed dressing. In our experiments, we evaluated the effect of seed coating with SAP on fungicide leaching and changes in their effectiveness in suppressing Fusarium culmorum infestation. Leaching of fungicide from wheat seeds coated with SAP after fungicide dressing, as measured by the inhibition test of mycelium growth under in vitro conditions, was reduced by 14.2–15.8% compared to seeds without SAP coating. Germination of maize seeds and growth of juvenile plants in artificially infected soil did not differ significantly between seeds dressed with fungicide alone and seeds treated with SAP and fungicide. In addition, plants from the seeds coated with SAP alone grew significantly better compared to untreated seeds. Real-time PCR also confirmed this trend by measuring the amount of pathogen DNA in plant tissue. Winter wheat was less tolerant to F. culmorum infection and without fungicide dressing, the seeds were unable to germinate under strong pathogen attack. In the case of milder infection, similar results were observed as in the case of maize seeds.

scholarly journals Evaluating Azoxystrobin Seed Coating Against Maize Late Wilt Disease Using a Sensitive qPCR-Based Method

Plant Disease ◽  
2019 ◽  
Vol 103 (2) ◽  
pp. 238-248 ◽  
Author(s):  
Ofir Degani ◽  
Daniel Movshowitz ◽  
Shlomit Dor ◽  
Ari Meerson ◽  
Yuval Goldblat ◽  
...  
Keyword(s):  
Phytopathogenic Fungus ◽  
Growth Stages ◽  
Seed Coating ◽  
Plant Weight ◽  
Infested Field ◽  
Harpophora Maydis ◽  
Pathogen Dna ◽  
Minor Disease

Harpophora maydis, a phytopathogenic fungus, causes late wilt, a severe vascular maize disease characterized by relatively rapid wilting of maize plants near fertilization. The disease is currently controlled using resistant varieties. Here, we evaluated seed coating efficiency with azoxystrobin against H. maydis in a series of in vitro and in vivo trials. A real-time polymerase chain reaction (qPCR)-based method was developed and proved to be a sensitive, accurate tool for monitoring H. maydis DNA inside infected seeds, sprouts, and tissues of mature plants. In the early growth stages, the chemical coating drastically reduced the pathogen DNA prevalence in host tissues and minimized the suppressing effect on the plants’ biomass and development. In an infested field, the qPCR assay identified the pathogen 20 days after seeding, up to a month before conventional PCR detection. In the resistant fodder maize cultivar 32D99, which showed only minor disease symptoms, the seed coating blocked fungal progression and increased cob and plant weight by 39 and 60%, respectively. Nevertheless, this treatment was unable to protect a sensitive maize hybrid, cultivar Prelude, at the disease wilting breakout (60 days after sowing). These results encourage further examination of azoxystrobin and other fungicides in the field using the qPCR detection method to evaluate their efficiency.

scholarly journals Compatibility of Azospirillum brasilense with Pesticides Used for Treatment of Maize Seeds

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Mariana S. Santos ◽  
Artur B. L. Rondina ◽  
Marco A. Nogueira ◽  
Mariangela Hungria
Keyword(s):  
Plant Growth ◽  
Root Hair ◽  
Azospirillum Brasilense ◽  
Plant Protection ◽  
Plant Growth Promoting Bacteria ◽  
Root Volume ◽  
Maize Seeds ◽  
Plant Growth Promoting ◽  
Growth Promoting

Seed treatment with chemical pesticides is commonly used as an initial plant protection procedure against pests and diseases. However, the use of such chemicals may impair the survival and performance of beneficial microorganisms introduced via inoculants, such as the plant growth-promoting bacterium Azospirillum brasilense. We assessed the compatibility between the most common pesticide used in Brazil for the treatment of maize seeds, composed of two fungicides, and one insecticide, with the commercial strains Ab-V5 and Ab-V6 of A. brasilense, and evaluated the impacts on initial plant development. The toxicity of the pesticide to A. brasilense was confirmed, with an increase in cell mortality after only 24 hours of exposure in vitro. Seed germination and seedling growth were not affected neither by the A. brasilense nor by the pesticide. However, under greenhouse conditions, the pesticide affected root volume and dry weight and root-hair incidence, but the toxicity was alleviated by the inoculation with A. brasilense for the root volume and root-hair incidence parameters. In maize seeds inoculated with A. brasilense, the pesticide negatively affected the number of branches, root-hair incidence, and root-hair length. Therefore, new inoculant formulations with cell protectors and the development of compatible pesticides should be searched to guarantee the benefits of inoculation with plant growth-promoting bacteria.

scholarly journals Screening of Antifungal and Antibacterial Activity of 90 Commercial Essential Oils against 10 Pathogens of Agronomical Importance

Foods ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1418
Author(s):  
Caroline De Clerck ◽  
Simon Dal Maso ◽  
Olivier Parisi ◽  
Frédéric Dresen ◽  
Abdesselam Zhiri ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Essential Oils ◽  
Plant Pathogens ◽  
Plant Protection ◽  
Fusarium Culmorum ◽  
Plant Protection Products ◽  
Colletotrichum Lindemuthianum ◽  
Alternative Methods ◽  
Organosulfur Compounds

Nowadays, the demand for a reduction of chemical pesticides use is growing. In parallel, the development of alternative methods to protect crops from pathogens and pests is also increasing. Essential oil (EO) properties against plant pathogens are well known, and they are recognized as having an interesting potential as alternative plant protection products. In this study, 90 commercially available essential oils have been screened in vitro for antifungal and antibacterial activity against 10 plant pathogens of agronomical importance. EOs have been tested at 500 and 1000 ppm, and measures have been made at three time points for fungi (24, 72 and 120 h of contact) and every two hours for 12 h for bacteria, using Elisa microplates. Among the EOs tested, the ones from Allium sativum, Corydothymus capitatus, Cinnamomum cassia, Cinnamomum zeylanicum, Cymbopogon citratus, Cymbopogon flexuosus, Eugenia caryophyllus, and Litsea citrata were particularly efficient and showed activity on a large panel of pathogens. Among the pathogens tested, Botrytis cinerea, Fusarium culmorum, and Fusarium graminearum were the most sensitive, while Colletotrichum lindemuthianum and Phytophthora infestans were the less sensitive. Some EOs, such as the ones from A. sativum, C. capitatus, C. cassia, C. zeylanicum, C. citratus, C. flexuosus, E. caryophyllus, and L. citrata, have a generalist effect, and are active on several pathogens (7 to 10). These oils are rich in phenols, phenylpropanoids, organosulfur compounds, and/or aldehydes. Others, such as EOs from Citrus sinensis, Melaleucacajputii, and Vanilla fragrans, seem more specific, and are only active on one to three pathogens. These oils are rich in terpenes and aldehydes.

scholarly journals Production of Microsclerotia From Entomopathogenic Fungi and Use in Maize Seed Coating as Delivery for Biocontrol Against Fusarium graminearum

2020 ◽  
Vol 4 ◽  
Author(s):  
Federico Rivas-Franco ◽  
John G. Hampton ◽  
Nora A. Altier ◽  
Jayanthi Swaminathan ◽  
Michael Rostás ◽  
...  
Keyword(s):  
Fusarium Graminearum ◽  
Entomopathogenic Fungi ◽  
Plant Pathogens ◽  
Plant Protection ◽  
Insect Pest ◽  
Seed Coating ◽  
Metarhizium Robertsii ◽  
Maize Seeds ◽  
High Concentrations ◽  
Root Tissues

The commercial use of the entomopathogenic fungi Metarhizium spp. in biopesticides has gained more interest since the discovery that several species of this genus are able to colonize roots. In general, commercial products with Metarhizium are formulated based on conidia for insect pest control. The process of mass production, harvesting, and formulation of infective conidia can be detrimental for conidial viability. Entomopathogenic fungi such as Metarhizium spp. are able to produce high concentrations of resistant structures, known as microsclerotia, when grown in liquid media. Microsclerotia are desiccation tolerant, with excellent storage stability, and are capable of producing high quantities of infective conidia after rehydration. The aim of this study was to evaluate microsclerotia production by different isolates of Metarhizium spp. and determine the effect of microsclerotia coated onto maize seeds on plant growth in the presence of soil-borne pathogen Fusarium graminearum. On average, ~1 × 105 microsclerotia/mL were produced by selected isolates of M. anisopliae (A1080 and F672) and Metarhizium robertsii (F447). Microsclerotia were formulated as granules with diatomaceous earth and used for seed coating, after which propagules produced around 5 × 106 CFU/g of seeds. In the presence of the plant pathogen, maize plants grown from untreated seeds had the lowest growth, while plants treated with the Metarhizium microsclerotia had significantly greater growth than the control plants. Hyphae were observed growing on and in root tissues in all the Metarhizium spp. treatments but not in samples from control plants. Metarhizium hyphal penetration points' on roots were observed 1 month after sowing, indicating the fungi were colonizing roots as endophytes. The results obtained indicate that microsclerotia can be coated onto seeds, providing plant protection against soil plant pathogens and a method to establish Metarhizium in the ecto- and endo-rhizosphere of maize roots, allowing the persistence of this biocontrol agent.

Efficacy of some rhizospheric and endophytic bacteria in vitro and as seed coating for the control of Fusarium culmorum infecting durum wheat in Tunisia

2016 ◽  
Vol 147 (3) ◽  
pp. 501-515 ◽  
Author(s):  
Nourhen Mnasri ◽  
Cynda Chennaoui ◽  
Samia Gargouri ◽  
Ridha Mhamdi ◽  
Kamel Hessini ◽  
...  
Keyword(s):  
Durum Wheat ◽  
Endophytic Bacteria ◽  
Fusarium Culmorum ◽  
Seed Coating

scholarly journals Inhibition of Premature Oocyte Maturation: A Role for Bone Morphogenetic Protein 15 in Zebrafish Ovarian Follicles

Endocrinology ◽  
2007 ◽  
Vol 148 (11) ◽  
pp. 5451-5458 ◽  
Author(s):  
Eric S. Clelland ◽  
Qian Tan ◽  
Ari Balofsky ◽  
Rosie Lacivita ◽  
Chun Peng
Keyword(s):  
Bone Morphogenetic Protein ◽  
Oocyte Maturation ◽  
Growth Phase ◽  
Early Growth ◽  
Preimmune Serum ◽  
Morphogenetic Protein ◽  
Bone Morphogenetic Protein 15 ◽  
Early Growth Phase

Bone morphogenetic protein-15 (BMP-15) is a member of the TGF-β superfamily known to regulate ovarian functions in mammals. Recently, we cloned zebrafish BMP-15 (zfBMP-15) cDNA and demonstrated that it may play a role in oocyte maturation. In this study, we further investigated the role of BMP-15 in zebrafish follicular development and oocyte maturation using an antiserum developed for zfBMP-15 and by microinjection of follicles with antisense zfBMP-15 N-morpholino oligonucleotides or an expression construct containing zfBMP-15 cDNA. Injection with antiserum caused a significant decrease in maturation-incompetent [insensitive to maturation-inducing hormone (MIH)] early growth phase follicles and a concomitant increase in mature follicles in vivo. In vitro maturation assays showed that incubation with antiserum resulted in a significant increase in oocyte maturation as compared with follicles incubated in preimmune serum or media control. Next, early growth phase follicles were collected and preincubated with either antiserum, preimmune serum, or medium control before treatment with MIH or human chorionic gonadotropin (hCG). Antiserum significantly increased oocyte maturation in response to MIH, but not to hCG, and enhanced basal maturation rate in longer-term incubations. Knockdown of BMP-15 in early growth stage follicles with a BMP-15 antisense oligonucleotide resulted in increased oocyte maturation, whereas microinjection of BMP-15 cDNA into oocytes significantly reduced MIH- and hCG-induced oocyte maturation in normally competent, mid-growth-phase follicles. Collectively, these findings suggest that BMP-15 modulates follicular growth and prevents premature oocyte maturation in zebrafish, in part, by suppressing the sensitivity of follicles to MIH.

scholarly journals Phytase-Producing Rahnella aquatilis JZ-GX1 Promotes Seed Germination and Growth in Corn (Zea mays L.)

2021 ◽  
Vol 9 (8) ◽  
pp. 1647
Author(s):  
Gui-E Li ◽  
Wei-Liang Kong ◽  
Xiao-Qin Wu ◽  
Shi-Bo Ma
Keyword(s):  
Seed Germination ◽  
Plant Growth ◽  
Biomass Accumulation ◽  
Root Surface ◽  
Phosphorus Concentration ◽  
Maize Seedlings ◽  
Total Phosphorus Concentration ◽  
Rahnella Aquatilis ◽  
Maize Seeds

Phytase plays an important role in crop seed germination and plant growth. In order to fully understand the plant growth-promoting mechanism by Rahnella aquatilis JZ-GX1，the effect of this strain on germination of maize seeds was determined in vitro, and the colonization of maize root by R. aquatilis JZ-GX1 was observed by scanning electron microscope. Different inoculum concentrations and Phytate-related soil properties were applied to investigate the effect of R. aquatilis JZ-GX1 on the growth of maize seedlings. The results showed that R. aquatilis JZ-GX1 could effectively secrete indole acetic acid and had significantly promoted seed germination and root length of maize. A large number of R. aquatilis JZ-GX1 cells colonized on the root surface, root hair and the root interior of maize. When the inoculation concentration was 107 cfu/mL and the insoluble organophosphorus compound phytate existed in the soil, the net photosynthetic rate, chlorophyll content, phytase activity secreted by roots, total phosphorus concentration and biomass accumulation of maize seedlings were the highest. In contrast, no significant effect of inoculation was found when the total P content was low or when inorganic P was sufficient in the soil. R. aquatilis JZ-GX1 promotes the growth of maize directly by secreting IAA and indirectly by secreting phytase. This work provides beneficial information for the development and application of R. aquatilis JZ-GX1 as a microbial fertilizer in the future.

scholarly journals The Potential of Rhizoctonia-Like Fungi for the Biological Protection of Cereals against Fungal Pathogens

Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 349
Author(s):  
Dominik Bleša ◽  
Pavel Matušinský ◽  
Romana Sedmíková ◽  
Milan Baláž
Keyword(s):  
Biological Control ◽  
Fungal Pathogens ◽  
Plant Pathogens ◽  
Higher Plants ◽  
Fusarium Culmorum ◽  
Suppressive Effect ◽  
Plant Production ◽  
Shoot Biomass ◽  
Organic Substrates

The use of biological control is becoming a common practice in plant production. One overlooked group of organisms potentially suitable for biological control are Rhizoctonia-like (Rh-like) fungi. Some of them are capable of forming endophytic associations with a large group of higher plants as well as mycorrhizal symbioses. Various benefits of endophytic associations were proved, including amelioration of devastating effects of pathogens such as Fusarium culmorum. The advantage of Rh-like endophytes over strictly biotrophic mycorrhizal organisms is the possibility of their cultivation on organic substrates, which makes their use more suitable for production. We focused on abilities of five Rh-like fungi isolated from orchid mycorrhizas, endophytic fungi Serendipita indica, Microdochium bolleyi and pathogenic Ceratobasidium cereale to inhibit the growth of pathogenic F. culmorum or Pyrenophora teres in vitro. We also analysed their suppressive effect on wheat infection by F. culmorum in a growth chamber, as well as an effect on barley under field conditions. Some of the Rh-like fungi affected the growth of plant pathogens in vitro, then the interaction with plants was tested. Beneficial effect was especially noted in the pot experiments, where wheat plants were negatively influenced by F. culmorum. Inoculation with S. indica caused higher dry shoot biomass in comparison to plants treated with fungicide. Prospective for future work are the effects of these endophytes on plant signalling pathways, factors affecting the level of colonization and surviving of infectious particles.

scholarly journals Topical Application of Double-Stranded RNA Targeting 2b and CP Genes of Cucumber mosaic virus Protects Plants against Local and Systemic Viral Infection

Plants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 963
Author(s):  
Maria C. Holeva ◽  
Athanasios Sklavounos ◽  
Rajendran Rajeswaran ◽  
Mikhail M. Pooggin ◽  
Andreas E. Voloudakis
Keyword(s):  
Cucumber Mosaic Virus ◽  
Mosaic Virus ◽  
Topical Application ◽  
Plant Virus ◽  
Plant Protection ◽  
Post Inoculation ◽  
Tobacco Plants ◽  
Double Stranded Rna

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.

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