scholarly journals Endophytic Yeast and Hosts: A Mutualistic Association Friendly to the Environment

Author(s):  
Esperanza del Pilar Infante Luna
2021 ◽  
Vol 288 (1944) ◽  
pp. 20202716
Author(s):  
Steve Kett ◽  
Ayush Pathak ◽  
Stefano Turillazzi ◽  
Duccio Cavalieri ◽  
Massimiliano Marvasi

Arthropods can produce a wide range of antifungal compounds, including specialist proteins, cuticular products, venoms and haemolymphs. In spite of this, many arthropod taxa, particularly eusocial insects, make use of additional antifungal compounds derived from their mutualistic association with microbes. Because multiple taxa have evolved such mutualisms, it must be assumed that, under certain ecological circumstances, natural selection has favoured them over those relying upon endogenous antifungal compound production. Further, such associations have been shown to persist versus specific pathogenic fungal antagonists for more than 50 million years, suggesting that compounds employed have retained efficacy in spite of the pathogens' capacity to develop resistance. We provide a brief overview of antifungal compounds in the arthropods’ armoury, proposing a conceptual model to suggest why their use remains so successful. Fundamental concepts embedded within such a model may suggest strategies by which to reduce the rise of antifungal resistance within the clinical milieu.


Author(s):  
Antonella Gagliardi ◽  
Valentina Totino ◽  
Fatima Cacciotti ◽  
Valerio Iebba ◽  
Bruna Neroni ◽  
...  

A microbial ecosystem in which bacteria no longer live in a mutualistic association is called dysbiotic. Gut microbiota dysbiosis is a condition related with the pathogenesis of intestinal illnesses (irritable bowel syndrome, celiac disease, and inflammatory bowel disease) and extra-intestinal illnesses (obesity, metabolic disorder, cardiovascular syndrome, allergy, and asthma). Dysbiosis status has been related to various important pathologies, and many therapeutic strategies aimed at restoring the balance of the intestinal ecosystem have been implemented. These strategies include the administration of probiotics, prebiotics, and synbiotics; phage therapy; fecal transplantation; bacterial consortium transplantation; and a still poorly investigated approach based on predatory bacteria. This review discusses the various aspects of these strategies to counteract intestinal dysbiosis.


1999 ◽  
Vol 7 ◽  
pp. 77-83
Author(s):  
Barry Scott ◽  
Carolyn Young ◽  
Lisa Mcmillan

Epichloë endophytes are an important group of filamentous fungi that confer on the grass host a range of biological benefits. However, endophyte synthesis of ergopeptine and indole-diterpene mammalian toxins in pasture grasses is detrimental to livestock grazing on that forage. The molecular cloning of the genes involved in the biosynthesis of these toxins will enhance our ability to maximise the beneficial attributes of this mutualistic association through the availability of DNA probes to screen and select for desirable endophytes and through our ability to genetically modify endophytes. Genes involved in the biosynthesis of both classes of alkaloids have recently been cloned from Claviceps purpurea and Penicillium paxilli. In both cases the genes are organised in large clusters; a feature that will facilitate a complete genetic analysis of each pathway and provide probes for isolating homologous genes from Epichloë endophytes. This paper reviews recent research developments on the molecular biology of these two pathways. Keywords: Epichloë endophytes, ergopeptines, gene cloning, gene manipulation, indole-diterpenes


2019 ◽  
Vol 85 (19) ◽  
Author(s):  
Luisa F. Cruz ◽  
Octavio Menocal ◽  
Julio Mantilla ◽  
Luis A. Ibarra-Juarez ◽  
Daniel Carrillo

ABSTRACT The ambrosia beetle Xyleborus volvulus Fabricius has been reported as a potential vector of the plant pathogen Raffaelea lauricola T.C. Harr., Fraedrich & Aghayeva that is affecting avocado orchards in South Florida. In this study, we examined its life cycle, process of gallery formation, gallery structure, and fungal associates by rearing one generation on avocado sawdust medium under control conditions. The adult foundress excavated a vertical tunnel that constituted the main gallery with a length of 2.5 cm, followed by the construction of up to six secondary galleries with a total length of 4.4 cm. The time period for one generation (egg to adult) was 28 days. Teneral males emerged 3 days after the emergence of the first females. The F1 generation did not significantly contribute to gallery expansion. Four species of Raffaelea and nine yeast species were recovered from galleries and beetles. Raffaelea arxii and Candida berthetii were the most frequent symbionts recovered from new adults and galleries. Candida berthetii dominated during the early stages of the gallery development, whereas R. arxii was most frequent in later stages. Other Raffaelea species were inconsistently isolated from galleries, which suggests a strong association between Xyleborus volvulus and both R. arxii and C. berthetii. These results suggest that R. arxii is the primary nutritional symbiont of X. volvulus and that yeast species may be pioneer colonizers that assist with the growth of fungal symbionts. IMPORTANCE Ambrosia beetles cultivate fungi in tunnels bored into weakened host trees. This obligate interaction is required for their survival as beetles feed on these symbiotic fungi, and the fungi benefit from transportation by the beetles. Xyleborus volvulus carries many nonpathogenic symbionts; however, recently the acquisition of Raffaelea lauricola (the causal agent of a lethal vascular disease of lauraceous trees) by this beetle has altered its status from wood degrader to potential pest in avocado. We conducted a study to understand the relationship of this beetle and its fungal associates. Our results show that X. volvulus has a multipartite flexible association with different Raffaelea species. The lack of fidelity in the mutualistic association may explain the acquisition of R. lauricola. Knowing the beetle biology and its mutualistic interactions furthers an understanding of the beetle’s role as a potential vector and in disease transmission.


Crustaceana ◽  
1996 ◽  
Vol 69 (1) ◽  
pp. 19-25 ◽  
Author(s):  
Dominique Doumenc ◽  
Charis Charles Chintiroglou ◽  
Danièle Guinot

AbstractA new symbiotic association between a deep-water homolid crab, Hypsophrys inflata Guinot & Richer de Forges, 1981 (Brachyura, Podotremata, Homolidae) and a sea anemone of the genus Isanthus (Anthozoa, Actiniaria, Isanthidae) is described from French Polynesia. The crab carries the anemone on its modified last pairs of legs. It is suggested that this represents a mutualistic association.


2019 ◽  
Vol 20 (3) ◽  
pp. 140-141
Author(s):  
Morgan V. Ritzi ◽  
Stephen D. Russell ◽  
M. Catherine Aime ◽  
Gordon G. McNickle

American chestnut (Castanea dentata) is critically endangered by chestnut blight caused by Cryphonectria parasitica. Beneficial interactions with mutualistic ectomycorrhizae sometimes confer resistance to pathogens; however, little is known about the mycorrhizal partners of American chestnut. Basidiocarps of Laccaria ochropurpurea were observed in a 10-year-old American chestnut plantation. The identity of the species was confirmed utilizing the nuclear ribosomal internal transcribed spacer. In spring 2018, root fragments were excised from beneath three American chestnut trees in three separate plots where basidiocarps were observed. Root tips with evidence of mycorrhizal fungal colonization were pooled, extracted, and sequenced to confirm both the plant host and mycorrhizal associates. To our knowledge, this is the first direct confirmation of American chestnut roots associated with L. ochropurpurea. We suggest further studies to investigate whether this association is common, whether it confers any disease resistance, and if this mutualistic association could be employed in restoration efforts of the American chestnut.


2004 ◽  
Vol 18 (3) ◽  
pp. 291 ◽  
Author(s):  
Kerrie A. Davies ◽  
Robin M. Giblin-Davis

Nematodes of the genus Fergusobia Currie (Tylenchida : Neotylenchidae) and flies of the genus Fergusonina Malloch (Diptera : Fergusoninidae) together form the only known mutualistic association between insects and nematodes that induces galls in young meristematic tissues in Myrtaceae. Six new species of Fergusobia are described (F. quinquenerviae, sp. nov., F. cajuputiae, sp. nov., F. dealbatae, sp. nov., F. leucadendrae, sp. nov., F.�nervosae, sp. nov., and F. viridiflorae, sp. nov.) and partial descriptions are presented for a further two species. Together, these taxa form a putative monophyletic group, apparently restricted to species of Melaleuca in the broad-leaved M. leucadendra-complex, from coastal Queensland and north-east New South Wales, Australia. Each species of nematode has a mutualistic association with a particular species of Fergusonina fly and (with one exception) each association is apparently restricted to one particular species of Melaleuca.


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