Eco-morphologic Aspects of Differentiation and Identification of Species Armillaria mellea Sensu Lato in Coppice Oakeries of Belgorod Region for the Purposes of Exploitation of Natural Resources

The article deals with matters of differentiation and identification of species of the complex Armillaria mellea sensu lato in loco in coppice oakeries of Belgorod region in Russian Federation. On the basis of results of comparison of local ecomorphotypes descriptions and known descriptions of Armillaria mellea s. l. European species it was stated that in Belgorod region’s oakeries there are two species belonging to the complex Armillaria mellea s. l.: Armillaria cepistipes and Armillaria gallic

Fungal phoenix rising from the ashes?

During May 2010, sporocarps of what appeared to be an Armillaria sp. were found in large clumps in historic Kirstenbosch Botanical Gardens on the foot of Table Mountain, Cape Town, South Africa. These sporocarps could be physically linked to the roots of unidentified dead trees and Protea spp. The aim of this study was to identify the Armillaria sp. found fruiting in Kirstenbosch. To achieve this goal isolates were made from the mycelium under the bark of dead roots linked to sporocarps. The ITS and IGS-1 regions were sequenced and compared to sequences of Armillaria spp. available on GenBank. Cladograms were generated using ITS sequences to determine the phylogenetic relationship of the isolates with other Armillaria spp. Sequence comparisons and phylogenetic analyses showed that the isolates represented A. mellea. They were also identical to isolates of this species previously discovered in the Company Gardens in South Africa and introduced from Europe apparently by the early Dutch Settlers. Armillaria mellea is alien and apparently invasive in Cape Town, fruits profusely and has the potential to spread to sensitive native forests on the foothills of the City

Bioactive metabolites from Trichoderma harzianum and Trichoderma longibrachiatum

The tea plant, Camellia sinensis (L.) O. Kuntze is an important crop in the agriculturally based economy of Kenya. Many diseases affect the tea plant but the most prevalent is armillaria root rot caused by the fungus Armillaria mellea. Compounds from the fermentation of Trichoderma species in different media were bioassayed against some selected gram-positive and gram-negative bacteria, fungi including Armillaria mellea, a yeast and a Mucor. Compounds obtained from T. harzianum, and T. longibrachiatum when cultured in various media were investigated individually for in-vitro antifungal and antibacterial activities by agar diffusion technique. Some of the compounds produced definite antifungal and antibacterial activities. 2-Phenylethanol (1) and tyrosol (2) obtained from T. harzianum are reported for the first time from Trichoderma species. The most active metabolite isolated from these strains was 6-n-pentyl-α-pyrone (3), which showed the highest antifungal and antibacterial activity and completely inhibited the growth of Armillaria mellea fungus at a concentration of 200 ppm. Compound 4 (sorbicillin) exhibited moderate activity against the fungal test organisms. KEY WORDS: Trichoderma harzianum, Trichoderma longibrachiatum, 2-Phenylethanol, Tyrosol, 6-n-Pentyl-•-pyrone, Armillaria Mellea  Bull. Chem. Soc. Ethiop. 2003, 17(2), 185-190

The cultivation, bioactive components and pharmacological effects of Armillaria mellea

Armillaria mellea, a symbiotic fungus in the underground tubers of Chinese medicinal orchid Gastrodia elata, is one of the main biological active components and pharmaceutical effects of its host gastrodia. The purpose of this review is to bring attention to the biological properties of this unique A. mellea mushroom and its constituents, as well as to suggest the potential for the development of new drugs related to this fungus. It contains various known and untapped bioactive metabolites such aspolysaccharides, sesquiterpene aryl esters, steroids and fibrinolytic enzymes. It could be exploited as an important source of new biological natural products with anticonvulsant, immunomodulatory andantimicrobial functions. The batch culture is preferred as an alternative means of getting bioactive components from Armellaria fermentation. Challenges in investigations on A. mellea include the optimization of culture parameters, the further elucidation of the molecular pharmacological mechanism and relationship between structure and function of their secondary metabolites

A native promoter and inclusion of an intron is necessary for efficient expression of GFP or mRFP in Armillaria mellea

Armillaria mellea is a significant pathogen that causes Armillaria root disease on numerous hosts in forests, gardens and agricultural environments worldwide. Using a yeast-adapted pCAMBIA0380 Agrobacterium vector, we have constructed a series of vectors for transformation of A. mellea, assembled using yeast-based recombination methods. These have been designed to allow easy exchange of promoters and inclusion of introns. The vectors were first tested by transformation into basidiomycete Clitopilus passeckerianus to ascertain vector functionality then used to transform A. mellea. We show that heterologous promoters from the basidiomycetes Agaricus bisporus and Phanerochaete chrysosporium that were used successfully to control the hygromycin resistance cassette were not able to support expression of mRFP or GFP in A. mellea. The endogenous A. mellea gpd promoter delivered efficient expression, and we show that inclusion of an intron was also required for transgene expression. GFP and mRFP expression was stable in mycelia and fluorescence was visible in transgenic fruiting bodies and GFP was detectable in planta. Use of these vectors has been successful in giving expression of the fluorescent proteins GFP and mRFP in A. mellea, providing an additional molecular tool for this pathogen

Estudios de interacción in vitro entre el hongo formador de micorrizas arbusculares Glomus intraradices y el hongo patógeno Armillaria mellea en vid

An interaction study was performed with mycorrhizal plants of the grapevine rootstock Richter 110 (Vitis berlandieri Planch × Vitis rupestris Scheele) and the root pathogenic fungus Armillaria mellea (Vahl:Fr.) P. Kumm using an autotrophic in vitro culture system. Micropropagated plantlets were transferred to Petri plates with MSR medium lacking sugar and vitamins. Inocula of Glomus intraradices (BEG 72) and of Armillaria mellea obtained from a root organ culture and from a mycelium colony grown in malt agar respectively, were added to the plates according to each treatment: non-inoculated, inoculated with G. intraradices, inoculated with A. mellea, and dual-inoculated plants. There were ten replicates per treatment. Fourteen weeks later, the pathogen's mycelium occupied most of the surface/volume of the plate and had produced rhizomorphs. In dual inoculated plates, A. mellea's growth was not affected by the presence of G. intraradices, but the latter produced a lower number of spores and its extraradical phase showed granulation, vacuolation and tip swelling. The pathogen induced necrosis and growth decrease in the root. Glomus intraradices alleviated these symptoms and there were no differences in root biomass between non-inoculated plants and plants inoculated with both fungi. There were no symptoms of the disease in shoots and G. intraradices stimulated shoot growth both, although mycorrhizal colonization was lower when A. mellea was present. No direct antagonism or antibiosis against the pathogen was observed, thus the protective effect exerted by the symbiotic fungus in grapevines must be indirect, mediated through the host plant physiology.Se estudió la interacción entre plantas micorrizadas del portainjerto de vid 110 Richter (Vitis berlandieri Planch × Vitis rupestris Scheele) y Armillaria mellea (Vahl:Fr.) P. Kumm en cultivo autotrófico in vitro. Plantas micropropagadas fueron transferidas a placas de Petri con medio MSR sin azúcar ni vitaminas. Inóculo de Glomus intraradices Schenck and Smith (BEG 72) obtenido a partir de un cultivo axénico de raíces transformadas micorrizadas, e inóculo de A. mellea obtenido en medio agar-malta, se añadieron a las placas según tratamiento: no inoculado, inoculación con G. intraradices, inoculación con A. mellea e inoculación combinada, estableciéndose 10 réplicas por tratamiento. Catorce semanas después, el micelio del hongo patógeno ocupaba casi la totalidad de la superficie/volumen de la placa y había producido rizomorfos. En placas con inoculación mixta, el desarrollo de A. mellea no se vio afectado por la presencia de G. intraradices, mientras que éste produjo menos esporas, y su fase extraradical presentaba granulaciones, vacuolaciones y engrosamientos en las terminaciones. El patógeno indujo necrosis y menor desarrollo radical. Glomus intraradices alivió estos síntomas, y no se observaron diferencias entre la biomasa radical de plantas no inoculadas y de plantas inoculadas con ambos hongos. No aparecieron síntomas de la enfermedad en la parte aérea y G. intraradices estimuló en cualquier caso el crecimiento, pero la colonización micorrícica fue menor en presencia del patógeno. No se observó antagonismo directo o antibiosis, el efecto de protección de la simbiosis micorrícica en vid frente a A. mellea debe ser indirecto, a través de la fisiología del hospedador

Zone lines in plant tissues

I. The black lines formed by Xylaria polymorpha (Pers.) Grey. in hardwoods. [From THE ANNALS OF APPLIED BIOLOGY, VoL. XX, No. 1, pp. 123 -145, FEBRUARY, 1933.]II . The black lines formed by Armillaria mellea (Vahl) Quel.The two papers presented in this thesis deal chiefly with a single type of zone line, namely, the rind of a pseudosclerotium buried in the tissues of the host. Although this is the commonest kind of zone line, there are several other types of zone line about which very little is known. A. brief outline of these lines has already been given on page 126 of the Xylaria paper, One such line is formed by the deposition of "wound gum" as in the attack by Fom.es applanatus on beech, while another is formed by antagonistic mycelia on the same substratum as has been described by Weir (2) in the case of F F. pinicola and F. fomentarius in birch. This latter phenomenon has also been described as being produced by strains of myxobacteria when colonised some little distance apart on agar (1). The writer has in his possession a zone line reputed to be formed between the rots of Polyporus adustus and F. igniarius but proof of this must await further investigation. Indeed, one of the difficulties of research on zone lines has been the necessity for working out the whole biology of the organisms concerned,as the zone lines, although often a matter for comment, have seldom been investigated.Mary accounts of zone- producing fungi even omit to mention the presence of zone lines in the substratum. Thus before any decision as to the nature of the zone line can be made it is generally necessary to make a complete investigation of the fungus suspected of forming it.This explanation of the zone line as the bounding layer of a peeudosolerotium in the substratum is one which may come to be applied to a large number of fungi. For example, it may be suggested that the black transverse /lines on leaves attacked by Lophodermium pinastri are of such a nature, while it can readily be shown by inoculation that Sclerotinia fructigena will form black zones in apples. The writer believes that it will be possible to demonstrate all stages between the true scierotium, the pseudosclerotium buried in the substratum and the case where part of the host, such as the fruit, forms in effect a sc lerotium for the attacking fungus. Indeed, this study of zone lines is only beginning to uncover facts which may throw more light on the physiology of the fungi and their methods of reproduction

Analysis of indole compounds in "Armillaria mellea" fruiting bodies

A TLC method with densitometric detection for identification and quantitation of indole compounds in methanolic extracts of fruiting bodies of Armillaria mellea (Vahl.) P. Kumm. (Basidiomycota) ñ Honey mushroom has been developed. The TLC method with densitometric detection was validated for determination of tryptamine and serotonin contents. The use of this chromatographic-densitometric method for analysis of extracts allowed for a precise, easy and quick determination of the compounds under study. We identified three physiologically active indole compounds: tryptamine, L- tryptophan and serotonin. This analysis demonstrated the highest contents of L-tryptophan (4.467 mg/100 g d.w.). The contents of tryptamine were comparable with the contents of serotonin and amounted to: 2.740 and 2.207 mg/100 g d. w

Inoculum Concentration of Armillaria mellea in the Rhizosphere of Intercropped Teak Plantation: the case of the Opro Forest Reserve, Ghana

Teak (Tectona grandis Linn. F.) is the most planted timber tree species in Ghana, with over 73,916 hectares of plantation established at the end of 2008. Many of the teak plantations established in the semi-deciduous forest zones were done using the taungya system with various intercrops. Symptoms of Armillaria (Vahl: Fr.) root-rot of teak have been reported in the taungya plantations, especially in the semi-deciduous forest zones. The study aimed to determine inoculum concentrations of Armillaria mellea in the rhizosphere soil of intercropped teak and compare with sole teak plantation. Mycoflora were isolated from rhizosphere soil of teak intercropped with pepper, okra, maize, yam or cassava at year one to year three sapling stage. Dilution plate technique was used for mycoflora isolation and dilution factor of 10-3 was inoculated on potato dextrose agar amended with chloramphenicol (25mg/l) and incubated at 280C for 14 days after which A. mellea colonies were identified and counted. More A. mellea (Vahl: Fr.) colonies were isolated from rhizosphere soils of intercropped teak plantations than non-intercropped. Differences in A. mellea colonies were more significant amongst intercrops than amongst age of teak plantation at (P ≤ 0.05). There were significantly (P ≤ 0.05) higher numbers of A. mellea colonies in rhizosphere soils of teak intercropped with cassava compared with other intercrops. Number of A. mellea colonies in rhizosphere soils of intercropped teak did not have linear relation with age of teak plantation. Intercropping could promote Armillaria root rot of teak especially with cassava as intercrop

In vitro antioxidant properties of polysaccharides from Armillaria mellea in batch fermentation

Antioxidant properties of exopolysaccharides (EPS) and intracellular polysaccharides (IPS) obtained respectively from mycelia and filtrates of submerged culture by Armillaria mellea in a 20-L stirred tank bioreactor were investigated. Effective production of EPS and IPS is available by submerged culture of A. mellea with respective number average molecular weights and protein/polysaccharide ratios as 7.68×106 Da and 7.68% as well as 5.65×106 Da and 5.26%. Both EPS and IPS exhibit powerful antioxidant activities by conjugated diene method, chelating effect on ferrous ions and scavenging effect on superoxide anion, as evidenced by their quite low EC50 values (< 5 mg/mL). Results confirmed that fermented A. mellea polysaccharides are potential antioxidant sources of both healthy medicine and food industries.Key words: Armillaria mellea, intracellular polysaccharide, exopolysaccharide, antioxidant activity