Search results for " MYC"
showing 10 items of 786 documents
Colonization of Plant Roots by Pseudomonads and AM Fungi: A Dynamic Phenomenon, Affecting Plant Growth and Health
2008
Because of their enormously large range of plant hosts and role in plant nutrition, arbuscular mycorrhizal (AM) fungi represent an extraordinarily fascinating field of study. Plant growth promotion effects by AM fungi were described as early as 1900 (Sthal 1900) and several data obtained in the second half of the last century support the idea that these microrganisms can act as biocontrol agents (BCA). The extent of root colonization is variable in different plants and under different environmental conditions (Giovannetti and Hepper 1985). Some effects of AM colonization on plants have been reported to be dependent on the degree of root colonization, while others have not. Root exudation an…
Plant defense responses induced by arbuscular mycorrhizal fungi
2002
Plants in their environment daily face many organisms such as fungi, bacteria, mycoplasms, viruses, nematodes, etc. Many of them are potential pathogens; in fact thousands of microorganisms are known to cause plant diseases. Despite this large number of deleterious microorganisms, most of the plants are resistant to their attack since they have developed effective mechanisms to protect themselves.
Arbuscular mycorrhizal fungi and micropropagation of high value crops
2002
Micropropagation has established its position as a way of propagating large numbers of uniform plants. For some plant species that are difficult to propagate by seeds or by conventional cuttings, this technique provides the only possible way of producing high quality plants. Micropropagation is widely used for propagation of high value crops like ornamentals, fruits, vegetables, plantation crops and spices (Vestberg and Estaun 1994). The micropropagation industry was growing fast in Europe up to 1992 (O’Riordain 1992) but after that the micropropagation industry seems to have stabilized its position although a slight increase in production of microplants was still recorded for the period 19…
Prevention of Fusarium head blight infection and mycotoxins in wheat with cut-and-carry biofumigation and botanicals
2020
Fusarium head blight (FHB) is a devastating fungal disease of wheat worldwide causing yield losses and grain contamination with mycotoxins that jeopardise food and feed safety. Field experiments using mulch layers or botanicals were conducted in two consecutive years to investigate prevention measures with the potential to suppress FHB and reduce mycotoxins in wheat. We simulated a system with high disease pressure, i.e. maize-wheat rotation under no-tillage, by applying maize residues artificially inoculated with Fusarium graminearum in field plots after wheat sowing. For mulch layers, a novel cut-and-carry biofumigation approach was employed. Cover crops grown in separate fields were harv…
The effects of parasite age and intensity on variability in acanthocephalan-induced behavioural manipulation.
2008
10 pages; International audience; Numerous parasites with complex life cycles are able to manipulate the behaviour of their intermediate host in a way that increases their trophic transmission to the definitive host. Pomphorhynchus laevis, an acanthocephalan parasite, is known to reverse the phototactic behaviour of its amphipod intermediate host, Gammarus pulex, leading to an increased predation by fish hosts. However, levels of behavioural manipulation exhibited by naturally-infected gammarids are extremely variable, with some individuals being strongly manipulated whilst others are almost not affected by infection. To investigate parasite age and parasite intensity as potential sources o…
Arbuscular mycorrhizal fungi altered the hypericin, pseudohypericin, and hyperforin content in flowers of Hypericum perforatum grown under contrastin…
2016
St. John's Wort (Hypericum perforatum) is a perennial herb able to produce water-soluble active ingredients (a.i.), mostly in flowers, with a wide range of medicinal and biotechnological uses. However, information about the ability of arbuscular mycorrhizal fungi (AMF) to affect its biomass accumulation, flower production, and concentration of a.i. under contrasting nutrient availability is still scarce. In the present experiment, we evaluated the role of AMF on growth, flower production, and concentration of bioactive secondary metabolites (hypericin, pseudohypericin, and hyperforin) of H. perforatum under contrasting P availability. AMF stimulated the production of aboveground biomass und…
Addition of high C:N crop residues to a P-limited substrate constrains the benefits of arbuscular mycorrhizal symbiosis for wheat P and N nutrition
2021
Many aspects concerning the role of arbuscular mycorrhizal (AM) fungi in plant nutrient uptake from organic sources remain unclear. Here, we investigated the contribution of AM symbiosis to N and P uptake by durum wheat after the addition of a high C:N biomass to a P-limited soil. Plants were grown in pots in the presence or absence of a multispecies AM inoculum, with (Org) or without (Ctr) the addition of 15N-labelled organic matter (OM). A further treatment, in which 15N was applied in mineral form (Ctr+N) in the same amount as that supplied in the Org treatment, was also included. Inoculation with AM had positive effects on plant growth in both control treatments (Ctr and Ctr+N), mainly …
Functional genomics of arbuscular mycorrhiza : decoding the symbiotic cell programme
2004
More extensive insight into plant genes involved in the symbiotic programme of arbuscular mycorrhiza is presently being achieved by global approaches that aim to discover novel genes or subsets of genes that are essential to cell programmes in the different steps of plantfungal interactions. The strategy of functional genomics based on large-scale differential RNA expression analyses (differential-display reverse transcriptase - PCR), electronic Northerns, suppressive subtractive hybridization, DNA chips) is presented, with a focus on arbuscular mycorrhiza in Pisum sativum and Medicago truncatula. The most recent knowledge about gene networks that are modulated in roots during arbuscular …
Contamination of fresh and dried tomato by Alternaria toxins in southern Italy.
2019
In the present investigation, fresh and dried tomato samples from markets and packinghouses located in Apulia region (southern Italy) were analysed for Alternaria toxins. All samples proved to be contaminated by tenuazonic acid (TeA); in particular, dried tomatoes were contaminated in the range 425-81,592 µg/kg, while fresh tomatoes were in the range 11-4560 µg/kg. The second most abundant toxin was alternariol monomethyl ether (AME), followed by tentoxin (TEN) and alternariol (AOH). Overall dried tomatoes were more contaminated than fresh ones, although this seemed not directly related to the presence of sodium chloride, utilized in the drying process. Five representative Alternaria isolat…
Colonization of adventitious roots ofMedicago truncatulabyPseudomonas fluorescensC7R12 as affected by arbuscular mycorrhiza
2008
Pseudomonas fluorescens C7R12 was previously shown to promote colonization of Medicago truncatula roots by Glomus mosseae BEG12. To gain more insight into the interaction between C7R12 and BEG12, the cell organization of C7R12 was characterized on adventitious roots mycorrhized or not with BEG12 and on extraradical hyphae. Bacterial cell observations were made using the immuno-fluorescence technique and confocal laser scanning microscopy. Five types of cell organization, so-called organization types (OT), were identified: small or large single cells, cells by pair and cells in microcolonies or in strings. The frequencies of each OT on the roots were expressed as the percentage of observatio…