In vitro mycorrhization of Casuarina and Allocasuarina species by Pisolithus isolates

1990 ◽  
Vol 68 (12) ◽  
pp. 2537-2542 ◽  
Author(s):  
Daniel Thoen ◽  
Bassirou Sougoufara ◽  
Yvon Dommergues

Five Casuarina species and five Allocasuarina species were inoculated in vitro with three isolates of Pisolithus sp. (Ors.X004 and Ors.7870 from Senegal, PR86 from Australia) to test their ability to form ectomycorrhizas. The mycorrhiza-forming ability varied between fungal isolates. The greatest differences occurred between Casuarina and Allocasuarina species. On Casuarina species, Pisolithus isolates formed only a fungal sheath. However, Ors.X004 induced well-developed ectomycorrhizas on Casuarina equisetifolia, whereas PR86 failed to form any fungal sheath on Casuarina cunninghamiana. On Allocasuarina species, Pisolithus isolates formed generally well-developed ectomycorrhizas. In addition, isolates Ors.7870 and PR86 invaded the cortical cells of Allocasuarina luehmannii and Allocasuarina decaisneana, respectively, thus forming ectendomycorrhizas. Epidermal cells of both Casuarina and Allocasuarina mycorrhizas showed tannin deposits. In fully developed ectomycorrhizas, the epidermal cells were radially elongated and the Hartig net never developed beyond the epidermal cells. In general, the ability to form ectomycorrhizas was more common with the genus Allocasuarina than the genus Casuarina.Key words: Casuarina, Allocasuarina, Pisolithus, ectomycorrhizas.


Botany ◽  
2019 ◽  
Vol 97 (8) ◽  
pp. 463-474 ◽  
Author(s):  
Hitoshi Murata ◽  
Shota Nakano ◽  
Takashi Yamanaka ◽  
Tomoko Shimokawa ◽  
Tomoko Abe ◽  
...  

Tricholoma matsutake is an ectomycorrhizal agaricomycete that produces matsutake mushrooms in association with conifers. Here, we isolated a pleiotropic mutant, designated as G1, following γ-ray irradiation of T. matsutake NBRC 33136. In addition to exhibiting increased cellulose- and amylose-degrading activities and altered mycelial morphology, G1 degenerated lateral roots and caused stunting or fatal wilting of seedlings of its symbiotic partner, Pinus densiflora, in vitro. A mutant, designated Ar 59, previously isolated after argon-ion beam irradiation, exhibited the same phenotypes as G1, but without its detrimental effects. Ar 59, like NBRC 33136, developed a Hartig net around healthy cortical cells that was composed of uniseriate hyphae. In G1-inoculated seedlings, the Hartig net was composed of heavily bundled hyphae penetrating the intercellular space, and it was accompanied by somewhat unusual forms of plant cortical cells. Sequences of rRNA gene-related markers, including four single nucleotide polymorphisms present within each strain, were 100% identical among NBRC 33136, G1, and Ar 59, indicating that they are mutants of the wild-type. Thus, γ-ray irradiation can convert the fungus from a beneficial to a harmful agent. These findings suggest the presence of an unknown mechanism in the fungal genome that can transform mutualism into parasitism.



1987 ◽  
Vol 17 (8) ◽  
pp. 976-990 ◽  
Author(s):  
H. E. Wilcox ◽  
C. J. K. Wang

Mycorrhizal associations formed by Phialophorafinlandia in Pinusresinosa were both ectomycorrhizal and ectendomycorrhizal with randomly distributed clusters of spherical hyphae within cells of the cortex. The ectomycorrhizal condition was common for short distances in the apices of short roots and in smaller diameter long roots, but intracellular invasion from the Hartig net occurred proximal to this zone, resulting in an ectendomycorrhizal structure. In large diameter long-root branches both conditions were found at different positions along the root axis. In addition, sclerotia-like inclusions occurred in the inner cortical cells, often radially opposite to the protoxylem. Mycorrhizal associations in Picearubens and Betulaalleghaniensis were predominantly ectomycorrhizal in all roots; sclerotial bodies could be present in the inner cortex of both hosts. The Hartig net extended to the endodermis in the spruce, but it surrounded only the epidermis in birch. The epidermal cells of birch ectendomycorrhizae elongated radially and obliquely to the root surface, but in spruce the mycorrhizal condition had no effect on radial dimensions of cortical cells.



2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Kamel Kamal Sabet ◽  
Magdy Mohamed Saber ◽  
Mohamed Adel-Aziz El-Naggar ◽  
Nehal Samy El-Mougy ◽  
Hatem Mohamed El-Deeb ◽  
...  

Five commercial composts were evaluated to suppress the root-rot pathogens (Fusarium solani (Mart.) App. and Wr, Pythium ultimum Trow, Rhizoctonia solani Kuhn, and Sclerotium rolfsii Sacc.) of cucumber plants under in vitro and greenhouse conditions. In vitro tests showed that all tested unautoclaved and unfiltrated composts water extracts (CWEs) had inhibitor effect against pathogenic fungi, compared to autoclaved and filtrated ones. Also, the inhibitor effects of 40 bacteria and 15 fungi isolated from composts were tested against the mycelial growth of cucumber root-rot pathogens. Twenty two bacteria and twelve fungal isolates had antagonistic effect against root-rot pathogens. The antagonistic fungal isolates were identified as 6 isolates belong to the genus Aspergillus spp., 5 isolates belong to the genus Penicillium spp. and one isolate belong to the genus Chaetomium spp. Under greenhouse conditions, the obtained results in pot experiment using artificial infested soil with cucumber root-rot pathogens showed that the compost amended soil reduced the percentage of disease incidence, pathogenic fungi population, and improved the cucumber vegetative parameters as shoot length, root length, fresh weight, and dry weight. These results suggested that composts are consequently considered as control measure against cucumber root-rot pathogens.



2011 ◽  
Vol 32 (2) ◽  
pp. 242-247 ◽  
Author(s):  
Amy E B Packard ◽  
Jason C Hedges ◽  
Frances R Bahjat ◽  
Susan L Stevens ◽  
Michael J Conlin ◽  
...  

Preconditioning induces ischemic tolerance, which confers robust protection against ischemic damage. We show marked protection with polyinosinic polycytidylic acid (poly-IC) preconditioning in three models of murine ischemia-reperfusion injury. Poly-IC preconditioning induced protection against ischemia modeled in vitro in brain cortical cells and in vivo in models of brain ischemia and renal ischemia. Further, unlike other Toll-like receptor (TLR) ligands, which generally induce significant inflammatory responses, poly-IC elicits only modest systemic inflammation. Results show that poly-IC is a new powerful prophylactic treatment that offers promise as a clinical therapeutic strategy to minimize damage in patient populations at risk of ischemic injury.



2001 ◽  
Vol 21 (1) ◽  
pp. 354-366 ◽  
Author(s):  
Carolina Sousa ◽  
Christina Johansson ◽  
Celine Charon ◽  
Hamid Manyani ◽  
Christof Sautter ◽  
...  

ABSTRACT A diversity of mRNAs containing only short open reading frames (sORF-RNAs; encoding less than 30 amino acids) have been shown to be induced in growth and differentiation processes. The early nodulin geneenod40, coding for a 0.7-kb sORF-RNA, is expressed in the nodule primordium developing in the root cortex of leguminous plants after infection by symbiotic bacteria. Ballistic microtargeting of this gene into Medicago roots induced division of cortical cells. Translation of two sORFs (I and II, 13 and 27 amino acids, respectively) present in the conserved 5′ and 3′ regions ofenod40 was required for this biological activity. These sORFs may be translated in roots via a reinitiation mechanism. In vitro translation products starting from the ATG of sORF I were detectable by mutating enod40 to yield peptides larger than 38 amino acids. Deletion of a Medicago truncatula enod40 region between the sORFs, spanning a predicted RNA structure, did not affect their translation but resulted in significantly decreased biological activity. Our data reveal a complex regulation of enod40action, pointing to a role of sORF-encoded peptides and structured RNA signals in developmental processes involving sORF-RNAs.



2005 ◽  
Vol 73 (2-3) ◽  
pp. 79-87 ◽  
Author(s):  
Eduardo Mitrani ◽  
Guy Nadel ◽  
Eilat Hasson ◽  
Esther Harari ◽  
Yael Shimoni
Keyword(s):  


Development ◽  
1985 ◽  
Vol 86 (1) ◽  
pp. 53-70
Author(s):  
J.-M. Verna

Axons from dorsal root ganglion cells cultured in a serum-free medium on poly-L-lysine or collagen substrates interact differently with dermis and epidermis. The orientation of neurite growth is not changed by encountering mesenchymal cells migrating from the outgrowth zone of a dermal explant, and neurites form close membrane associations with some dermal cells; in contrast, neurites strongly avoid epidermis and deviate around the edge of an epidermal explant. When cultures are grown on polylysine this avoidance behaviour occurs at a distance from the epidermis. It is suppressed in the presence of necrotic epidermal cells. We suggest that this avoidance is due to epidermal diffusible factor(s) which bind preferentially to polylysine. The possibility of an absence of specific recognition cues between neurites and epidermal cells is discussed.



1990 ◽  
Vol 68 (3) ◽  
pp. 579-593 ◽  
Author(s):  
H. B. Massicotte ◽  
R. L. Peterson ◽  
C. A. Ackerley ◽  
L. H. Melville

The ontogeny and ultrastructure of ectomycorrhizae synthesized between Betula alleghaniensis (yellow birch) and Pisolithus tinctorius, a broad host range fungus, were studied to determine the structural modifications in both symbionts during ectomycorrhiza establishment. A number of stages, including initial contact of hyphae with the root surface, early mantle formation, and mature mantle formation, were distinguished. Interactions between hyphae and root hairs were frequent. As a paraepidermal Hartig net developed, root epidermal cells elongated in a radial direction, but wall ingrowths were not formed. Repeated branching of Hartig net hyphae resulted in extensive fine branches and the compartmentalization of hyphal cytoplasm. Nuclei and elongated mitochondria were frequently located in the narrow cytoplasmic compartments, and [Formula: see text] thickenings developed along walls of cortical cells in primary roots.



2010 ◽  
Vol 22 (3) ◽  
pp. 209-215 ◽  
Author(s):  
Zanderluce G. Luis ◽  
Kadja Milena G. Bezerra ◽  
Jonny Everson Scherwinski-Pereira

Changes in the leaf structure of plants grown in different conditions have been reported, such as increase in size and density of stomata and reduction in stomatal control, amount of epicuticular wax, and mesophyll thickness, with a high diversity of intercellular spaces. However, these changes are highly variable depending on the physiological and morphological characteristics of each species. The objective of this work was to analyze the adaptability and anatomical plasticity of oil palm seedlings produced after embryo rescue and pre-germinated seeds. Expanded leaves were prepared for evaluation of morphometric data and anatomical structures. It was verified that the environmental conditions in vitro negatively influenced the stomata density, epidermal and hypodermal thickness, and the values for the expansion cells and leaf mesophile. Anatomically, the oil palm leaves present the same tissues composition in both growth conditions, with uniseriate epidermal cells, and tetracitic stomata occurring in both epidermal surfaces. Epidermal cells from in vitro plants are thinner than ones from greenhouse. The midrib of leaves from greenhouse plants are more developed and is composed by only one central vascular bundle, while plants from in vitro cultivation developed three to four collateral vascular bundles.



Sign in / Sign up

Export Citation Format

Share Document