Ultrastructure of Mycorrhizas of Dracophyllum secundum R. Br. (Ericales:Epacridaceae)

1989 ◽  
Vol 16 (1) ◽  
pp. 147 ◽  
Author(s):  
WK Allen ◽  
WG Allaway ◽  
GC Cox ◽  
PG Valder
Keyword(s):  
Structural Integrity ◽  
Fungal Endophytes ◽  
Mycorrhizal Fungus ◽  
Fungal Endophyte ◽  
Epidermal Cells ◽  
Root Cells ◽  
Hair Roots ◽  
Ericoid Mycorrhizas ◽  
Hyphal Coils ◽  
Plant Plasma Membrane

Dracophyllum secundum R. Br. (Epacridaceae) often possessed ericoid mycorrhizas; fungal endophytes formed coils within cells of the epidermis of hair-roots. The plant plasma membrane extended around the hyphae. In some epidermal cells of hair-roots, both plant and fungal cells retained their structural integrity, both partners showing mitochondrial, vacuolar and lipid droplet profiles, and with much of the plant cytoplasm associated with the hyphal coils. In other epidermal cells of hair-roots, fungal coils were present but cytoplasmic features of both symbionts appeared to have broken down. Some epidermal cells showed no evidence of fungal infection. These three arrangements could occur in root-cells of the same age, and are interpreted as resulting from different stages in the development and degeneration of the infection by the mycorrhizal fungus. Two structural types of fungal endophyte here found in ericoid mycorrhizas in D. secundum: one with simple septa, Woronin bodies and two-layered walls (presumed to be an Ascomycete), and another with dolipore septa with imperforate parenthesomes (presumed to be a Basidiomycete). The possibilities that the mycorrhizas may be seasonal, and that mycorrhizal status varies from place to place, are discussed.

A light and electron microscope study of the fungal endophytes in the sporophyte and gametophyte of Lycopodium cernuum with observations on the gametophyte–sporophyte junction

1992 ◽  
Vol 70 (1) ◽  
pp. 58-72 ◽  
Author(s):  
Jeffrey G. Duckett ◽  
Roberto Ligrone
Keyword(s):  
Root Nodules ◽  
Fungal Endophytes ◽  
Fungal Endophyte ◽  
Peninsular Malaysia ◽  
Epidermal Cells ◽  
Host Cells ◽  
Wall Material ◽  
Intercellular Spaces ◽  
Host Cytoplasm ◽  
Fungal Associations

The ventral epidermal cells of the photosynthetic, surface-living gametophytes of Lycopodium cernuum, collected from moist shaded banks in Peninsular Malaysia, contain an aseptate fungus. In some cells the hyphae are thick walled and form coils encapsulated by a thin layer of host wall material. In others the fungus is thin walled and shows limited differentiation into larger trunk hyphae and arbuscules. The adjacent host cytoplasm, separated from the fungus by a granular interfacial matrix, contains numerous chloroplasts, mitochondria, and microtubules. The hyphae contact the substratum via the ventral walls of the epidermal cells and the rhizoids are free from infection. In the protocorm and root nodules, aseptate hyphae initially colonize mucilage-filled schizogenous intercellular spaces. Subsequent invasion of the host cells is associated with the development of massive overgrowths of host wall material. The fungal associations in L. cernuum share a mixture of attributes otherwise found in different angiosperm mycorrhizae and in mycotrophic relationships in liverworts. Wall ingrowths are present in both the gametophyte and sporophyte cells in the placenta of L. cernuum. The very limited development of the placenta, compared with L. appressum, certain bryophytes and ferns, the diminutive size, and early senescence of the gametophytes of L. cernuum are all linked to the presence of the protocorm. This massive absorptive organ, homologous to a foot, in terms of its position in sporophyte ontogeny, but external to the parent gametophyte, derives its nutrition partly from photosynthesis and partly from its fungal endophyte. Key words: chloroplasts, Lycopodium, mycorrhiza, pteridophytes, root nodules, symbiosis, transfer cells.

Conidiogenesis in Oidiodendron periconioides and ultrastructure of ericoid mycorrhizas formed with Rhododendron brachycarpum

1993 ◽  
Vol 71 (11) ◽  
pp. 1481-1485 ◽  
Author(s):  
R. S. Currah ◽  
A. Tsuneda ◽  
S. Murakami
Keyword(s):  
Complex System ◽  
Physiological Role ◽  
Epidermal Cells ◽  
Peat Moss ◽  
Ericoid Mycorrhiza ◽  
Hair Roots ◽  
Oidiodendron Maius ◽  
Ericoid Mycorrhizas ◽  
Scanning Electron

Oidiodendron periconioides was isolated from hair roots of seedlings of Rhododendron brachycarpum growing in pots containing a commercial peat moss in Japan. The unusual process of conidiogenesis in O. periconioides involved the formation of conidia from vesicle-like swellings that developed from vegetative hyphae or from the apex of a mononematous conidiophore. Scanning electron microscope examinations of mature conidia revealed that they were regularly dimpled, giving them the characteristic and previously reported radiate pattern of sculpturing visible with the light microscope. Oidiodendron periconioides formed ericoid mycorrhizas that were morphologically and ultrastructurally similar to previously studied ericoid systems involving Oidiodendron maius and Hymenoscyphus ericae, and a few other species of Rhododendron. Rough-walled hyphae grew appressed to the epidermal cells of young hair roots, penetrated the external walls via narrow penetration tubes, and invaginated the plasma membrane of the host cell during the process of forming a complex system of hyphal loops. Infection was restricted to the zone proximal to the active region of the meristem. Hyphal complexes were short-lived and degenerated as the epidermal cells matured and died. The physiological role of O. periconioides as a mycorrhizal endophyte is unknown. Key words: ericoid mycorrhiza, Oidiodendron periconioides, Rhododendron brachycarpum, conidiogenesis.

Spatial distribution of fungal endophyte genotypes in a Woollsia pungens (Ericaceae) root system

2002 ◽  
Vol 50 (5) ◽  
pp. 559 ◽  
Author(s):  
David J. Midgley ◽  
Susan M. Chambers ◽  
John W. G. Cairney
Keyword(s):  
Root System ◽  
Fungal Endophytes ◽  
Rflp Analysis ◽  
Its Region ◽  
Inter Simple Sequence Repeat ◽  
Fungal Endophyte ◽  
Type I ◽  
Rflp Type ◽  
Hair Roots ◽  
Woollsia Pungens

Fungal endophytes were isolated from hair roots of Woollsia pungens Cav. (Muell.) and mapped according to the root portions from which they were isolated. A total of 119 isolates was obtained and restriction fragment length polymorphism (RFLP) analysis of the internal transcribed spacer (ITS) region indicated that the isolate assemblage comprised five RFLP types. ITS sequence comparison revealed that RFLP Types I and II had 99.6–99.8% sequence identity with known ericoid mycorrhizal endophytes from Australian epacrids. The remaining three RFLP types were most similar to non-mycorrhizal ascomycetes. Eighty-five per cent of isolates obtained were of RFLP Type I and these were widespread within the root system. Inter-simple sequence repeat PCR suggested that 94% of RFLP Type I isolates were of a single genotype that was widely distributed within the root system, with the remaining five isolates each representing a different genotype. Apparent spatial dominance of the root system by a single fungal genotype may indicate limited functional diversity in the mycorrhizal endophyte assemblage.

scholarly journals Control of Verticillium Yellows in Chinese Cabbage by the Dark Septate Endophytic Fungus LtVB3

2004 ◽  
Vol 94 (5) ◽  
pp. 412-418 ◽  
Author(s):  
K. Narisawa ◽  
F. Usuki ◽  
T. Hashiba
Keyword(s):  
Chinese Cabbage ◽  
Virulent Strain ◽  
Fungal Endophytes ◽  
Fungal Endophyte ◽  
Root Cells ◽  
Disease Symptoms ◽  
Phialocephala Fortinii ◽  
Bait Plants ◽  
Wall Appositions ◽  
Heteroconium Chaetospira

Three hundred forty-nine fungal endophytes were obtained from a total of 1,214 root segments of eggplant, melon, barley, and Chinese cabbage grown as bait plants in a mixed soil made up of samples from different forest soils in Alberta and British Columbia, Canada. Three of the 349 isolates, when inoculated in axenically reared Chinese cabbage seedlings grown in petri dishes, almost completely suppressed the effects of a postinoculated and virulent strain of Verticillium longisporum. Two isolates effective against the pathogen were Phialocephala fortinii, which had been obtained from the roots of eggplant and Chinese cabbage. The third isolate was a dark septate endophytic (DSE) fungus obtained from barley roots. Hyphae of P. fortinii grew along the surface of the root and formed microsclerotia on or in the epidermal layer. Hyphae of the DSE fungus heavily colonized root cells of the cortex. Seedlings grown for 1 week in the presence of the endophytes were then challenged with the Verticillium pathogen. In DSE-treated roots, some of cell walls in the epidermal and cortical layers showed cell wall appositions and thickenings, which appeared to limit the ingress of the pathogen into adjacent cells. Such marked host reactions were not observed in the root cells colonized by P. fortinii. Chinese cabbage preinoculated with the above endophytes and, for comparison, a previously reported disease-suppressive fungal endophyte, Heteroconium chaetospira, were transplanted into the field and disease symptoms were assessed. The DSE could most effectively inhibit the development of Verticillium yellows, with reductions in the percentages of external and internal disease symptoms of 84 and 88%, respectively. The protective values against the disease are extremely high compared with those of other isolates. Most of the DSE-treated plants in the plots achieved marketable quality.

scholarly journals Tree Diversity Reduces Fungal Endophyte Richness and Diversity in a Large-Scale Temperate Forest Experiment

Diversity ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 234 ◽  
Author(s):  
Eric A. Griffin ◽  
Joshua G. Harrison ◽  
Melissa K. McCormick ◽  
Karin T. Burghardt ◽  
John D. Parker
Keyword(s):  
Phylogenetic Diversity ◽  
Large Scale ◽  
High Throughput Sequencing ◽  
Spatial Scales ◽  
Fungal Endophytes ◽  
Fungal Endophyte ◽  
Tree Diversity ◽  
Trophic Levels ◽  
Community Diversity ◽  
And Function

Although decades of research have typically demonstrated a positive correlation between biodiversity of primary producers and associated trophic levels, the ecological drivers of this association are poorly understood. Recent evidence suggests that the plant microbiome, or the fungi and bacteria found on and inside plant hosts, may be cryptic yet important drivers of important processes, including primary production and trophic interactions. Here, using high-throughput sequencing, we characterized foliar fungal community diversity, composition, and function from 15 broadleaved tree species (N = 545) in a recently established, large-scale temperate tree diversity experiment using over 17,000 seedlings. Specifically, we tested whether increases in tree richness and phylogenetic diversity would increase fungal endophyte diversity (the “Diversity Begets Diversity” hypothesis), as well as alter community composition (the “Tree Diversity–Endophyte Community” hypothesis) and function (the “Tree Diversity–Endophyte Function” hypothesis) at different spatial scales. We demonstrated that increasing tree richness and phylogenetic diversity decreased fungal species and functional guild richness and diversity, including pathogens, saprotrophs, and parasites, within the first three years of a forest diversity experiment. These patterns were consistent at the neighborhood and tree plot scale. Our results suggest that fungal endophytes, unlike other trophic levels (e.g., herbivores as well as epiphytic bacteria), respond negatively to increasing plant diversity.

Revealing the endophytic mycoflora in tea (Camellia sinensis) leaves in Sri Lanka: the first comprehensive study

Phytotaxa ◽  
2021 ◽  
Vol 514 (3) ◽  
pp. 247-260
Author(s):  
KASUN THAMBUGALA ◽  
DINUSHANI DARANAGAMA ◽  
SAGARIKA KANNANGARA ◽  
THENUKA KODITUWAKKU
Keyword(s):  
Sri Lanka ◽  
Camellia Sinensis ◽  
Endophytic Fungi ◽  
Sequence Data ◽  
Fungal Endophytes ◽  
Fungal Endophyte ◽  
Tea Leaves ◽  
Molecular Sequence Data ◽  
Molecular Sequence ◽  
Rdna Sequence Data

Endophytic fungi are a diverse group of microorganisms that live asymptomatically in healthy tissues of host and they have been reported from all kinds of plant tissues such as leaves, stems, roots, flowers, and fruits. In this study, fungal endophytes associated with tea leaves (Camellia sinensis) were collected from Kandy, Kegalle, and Nuwara Eliya districts in Sri Lanka and were isolated, characterized, and identified. A total of twenty endophytic fungal isolates belonging to five genera were recovered and ITS-rDNA sequence data were used to identify them. All isolated endophytic fungal strains belong to the phylum Ascomycota and the majority of these isolates were identified as Colletotrichum species. Phyllosticta capitalensis was the most commonly found fungal endophyte in tea leaves and was recorded in all three districts where the samples were collected. This is the very first investigation on fungal endophytes associated with C. sinensis in Sri Lanka based on molecular sequence data. In addition, a comprehensive account of known endophytic fungi reported worldwide on Camellia sinensis is provided.

scholarly journals Relationships between Foliar Fungal Endophyte Communities and Ecophysiological Traits of CAM and C3 Epiphytic Bromeliads in a Neotropical Rainforest

Diversity ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 378 ◽  
Author(s):  
Peter H. Tellez ◽  
Carrie L. Woods ◽  
Stephen Formel ◽  
Sunshine A. Van Bael
Keyword(s):  
Fungal Endophytes ◽  
Leaf Traits ◽  
Fungal Endophyte ◽  
Leaf Water Content ◽  
Leaf Toughness ◽  
Vascular Epiphytes ◽  
Ecophysiological Traits ◽  
Photosynthetic Pathways ◽  
Relative Abundances ◽  
Epiphytic Bromeliads

Vascular epiphytes contribute up to 35% of the plant diversity and foliar biomass of flowering plants. The family Bromeliaceae is a monophyletic group of plants native to the Neotropics. Epiphytic bromeliads form associations with distinct groups of organisms but their relationship with foliar fungal endophytes remain underexplored. In this study we examined the relationship of foliar fungal endophytes to host photosynthetic pathways and associated ecophysiological traits. We sampled the fungal endophyte communities of 67 host individuals in six epiphytic bromeliad species differing in C3 and crassulacean acid metabolism (CAM) photosynthetic pathways. We tested whether endophyte assemblages were associated with ecophysiological leaf traits related to host photosynthetic pathways. Our results indicate that (1) C3 and CAM bromeliads host dissimilar endophyte assemblages, (2) endophyte communities in C3 bromeliads are characterized by variable relative abundances of fungal orders; conversely, CAM associated endophyte communities were characterized by consistent relative abundances of fungal orders, and (3) endophyte communities in bromeliads are distributed along a continuum of leaf toughness and leaf water content. Taken together, our study suggests that host physiology and associated ecophysiological traits of epiphytic bromeliads may represent biotic filters for communities of fungal endophytes in the tropics.

Anatomy and ultrastructure of a Rhododendron root–fungus association

1980 ◽  
Vol 58 (23) ◽  
pp. 2421-2433 ◽  
Author(s):  
T. A. Peterson ◽  
W. C. Mueller ◽  
L. Englander
Keyword(s):  
Fungal Infection ◽  
Secondary Growth ◽  
Cortical Layer ◽  
Electron Microscopic ◽  
Cortical Cells ◽  
Host Cytoplasm ◽  
Hair Roots ◽  
Short Period ◽  
Infected Cells ◽  
Hyphal Coils

Light and electron microscopic investigations of the roots of Rhododendron and other ericaceous plants growing in the vicinity of Clavaria fruiting structures showed a fungal infection consistently associated with the epidermal and cortical cells of the "hair roots." Uninfected hair roots consisted of an epidermis and a one cell thick cortical layer surrounding the stele. Secondary growth in the stele and formation of a cork layer by division of the pericycle caused the cortex and epidermis to slough as the root matured. The structure of the infected hair roots was similar except for the presence of fungus in epidermal and cortical cells. As judged by the appearance of septa, at least two fungi were involved, one with dolipore septa that formed hyphal coils in the infected cells, and one with septa associated with Woronin bodies that occurred as single hyphal strands. Hyphae were found penetrating the cells from the exterior of the root and also passing from cell to cell. No correlation between fungal infection and the phenolic content of the cells could be made. Dissolution of both the fungal and host cytoplasm appeared to occur as the cells were sloughed. It appears that the fungus–root relationship is complex and is limited in duration to a short period of time during the development of the hair roots.

Fungal endophytes of Festuca rubra increase in frequency following long-term exclusion of rabbits

Botany ◽  
2015 ◽  
Vol 93 (4) ◽  
pp. 233-241 ◽  
Author(s):  
James S. Santangelo ◽  
Nash E. Turley ◽  
Marc T.J. Johnson
Keyword(s):  
Plant Growth ◽  
Intraspecific Competition ◽  
Fungal Endophytes ◽  
Natural Populations ◽  
Fungal Endophyte ◽  
Festuca Rubra ◽  
Red Fescue ◽  
Grass Endophyte ◽  
Defensive Mutualism ◽  
Endophyte Infection

Plant – fungal endophyte interactions are common in nature and they can shape the ecology of plants. Vertically transmitted endophytes are hypothesized to serve as mutualists, protecting plants from herbivores. If this hypothesis is true, then we expect endophytes to be most abundant in the presence of herbivores and least abundant in their absence, assuming endophytes incur a cost to their host. We tested this prediction by studying the effects of intense rabbit (Oryctolagus cuniculus Linnaeus) grazing on grass–endophyte interactions at Silwood Park, UK. We examined seeds of red fescue (Festuca rubra L.) collected from 15 natural populations that were protected from rabbits for 0.3–21 years. Contrary to our prediction, the mean proportion of seeds with endophytes increased 1.84×, from 0.45 to 0.83, following 21 years of rabbit exclusion. To better understand the mechanisms driving this increase in frequency, we conducted a fully factorial greenhouse experiment where we manipulated the presence or absence of endophyte infection, intraspecific competition, and simulated grazing on F. rubra plants. In both damaged and undamaged treatments, infected plants produced approximately twice as much biomass as uninfected plants, and endophytes did not influence tolerance to herbivory. These results suggest that endophytes directly change plant growth but not compensatory responses to damage. In the absence of competitors, infected plants produced 2.17× more biomass than uninfected plants, whereas in the presence of competitors, infected plants produced only 1.55× more biomass than uninfected plants. This difference suggests that intraspecific competition might lessen the benefits of endophyte infection. Our results do not support the defensive mutualism hypothesis, but instead suggest that endophyte-induced plant growth is important in shaping the costs and benefits of endophytes in our system.

Sign in / Sign up

Export Citation Format

Share Document