<i>Geosiphon pyriforme</i>, an Endosymbiotic Association of Fungus and Cyanobacteria: the Spore Structure Resembles that of Arbuscular Mycorrhizal (AM) Fungi

Schüßler, Arthur; Mollenhauer, Dieter; Schnepf, E.; Kluge, Manfred

doi:10.1111/j.1438-8677.1994.tb00406.x

Cited by 85 publications

(36 citation statements)

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“…Some vacuoles contain BLO with a rod shape and thick wall. Similar microorganisms are also commonly associated with AMF (Schüßler et al 1994). The BLO were often located in the vacuoles, as already reported by some authors Scannerini & Bonfante 1991).…”

Section: Discussionsupporting

confidence: 80%

Element storage in spores of Gigaspora margarita Becker & Hall measured by electron energy loss spectroscopy (EELS)

Cruz

2004

Acta Bot. Bras.

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RESUMO -(Elementos de armazenamento em esporos de Gigaspora margaritaBecker & Hall medidos por espectroscopia com perda de energia em elétrons (EEES)). As estruturas de armazenamento em esporos de Gigaspora margarita Becker & Hall, um fungo micorrízico arbuscular, foram analisadas por microscópio eletrônico de transmissão (MET) e espectroscopia com perda de energia em elétrons (EEES). Os esporos foram hidratados, criofixados por pressão em baixa temperatura e submetidos a substituição em congelamento, embebidos e preparados para observações no MET. As técnicas de criofixação revelaram que as estruturas de armazenamento nos esporos são compostas de lipídios, grânulos elétron densos (GED), corpos protéicos e partículas de glicogênio. Por EEES foi detectada a presença de nitrogênio (N) e carbono (C) nestas estruturas de armazenamento e em organismos similares a bactérias (OSB). Uma pequena quantia de P foi detectada nos vacúolos e nos OSB. O exame por MET e EEES indicaram a presença de estruturas de armazenamento nos esporos e alguns elementos essenciais (N, P e C) nessas. Palavras-chave: fungo micorrízico arbuscular, EELS, armazenamento, microscópio eletrônico de transmissãoABSTRACT -(Element storage in spores of Gigaspora margarita Becker & Hall measured by electron energy loss spectroscopy (EELS)). The storage structures of spores of Gigaspora margarita Becker & Hall, an arbuscular mycorrhizal fungus, were analyzed by a transmission electronic microscope (TEM) and electron energy loss spectroscopy (EELS). The spores were hydrated, cryofixed using high pressure freezing, submitted to freeze substitution, embedded and prepared for TEM observations. The cryotechniques revealed that the storage structures in the spores are composed of lipids, electron dense granules (EDG), protein bodies and glycogen particles. The EELS detected the presence of nitrogen (N) and carbon (C) in these storage structures and in Bacteria-like organisms (BLO). Some amount of P was detected in the vacuoles and in BLO. The TEM and EELS techniques indicate the presence of storage structures in the fungal spore, and some essential elements (N, P and C) in these structures.

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Section: Discussionsupporting

confidence: 80%

Element storage in spores of Gigaspora margarita Becker & Hall measured by electron energy loss spectroscopy (EELS)

Cruz

2004

Acta Bot. Bras.

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“…F. Wettst., Otospora and Scutellospora (INVAM;Walker 1983;Morton and Benny 1990;Schüßler et al 1994;Walker et al , 2007De Souza et al 2005), of which Acaulospora, Archaeospora, Ambispora and Scutellospora also produce germination shields (see below), but is unlikely to be homologous among these diverse groups. In Scutellospora, an evanescent outer wall is only known in the ornamented species S. spinosissima C. Walker & Cuenca, S. reticulata De Souza et al 2005), whereas it is a typical feature of Acaulospora, Archaeospora, Ambispora and Otospora (Stürmer and Morton 1999;Morton and Redecker 2001;Spain et al 2006;Palenzuela et al 2008).…”

Section: Scale Bar=30 µM Bmentioning

confidence: 99%

Acaulosporoid glomeromycotan spores with a germination shield from the 400-million-year-old Rhynie chert

et al. 2008

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This work has been made available by the University of Kansas Libraries' Office of Scholarly Communication and Copyright. Please share your stories about how Open Access to this article benefits you.This is the published version of the article, made available with the permission of the publisher. The original published version can be found at the link below. Dotzler, N., Walker, C., Krings, M., Hass, H., Kerp, H., Taylor, T., Agerer, R. 2009. Acaulosporoid glomeromycotan spores with a germination shield from the 400-million-year-old Rhynie chert. Mycol Progress 8:9-18. Abstract Scutellosporites devonicus from the Early Devonian Rhynie chert is the only fossil glomeromycotan spore taxon known to produce a germination shield. This paper describes a second type of glomeromycotan spore with a germination shield from the Rhynie chert. In contrast to S. devonicus, however, these spores are acaulosporoid and develop laterally in the neck of the sporiferous saccule. Germination shield morphology varies, from plate-like with single or double lobes to tongue-shaped structures usually with infolded margins that are distally fringed or palmate. Spore walls are complex and appear to be constructed of at least three wall groups, the outermost of which includes the remains of the saccule. The complement of features displayed by the fossils suggests a relationship with the extant genera Ambispora, Otospora, Acaulospora or Archaeospora, but which of these is the closest extant relative cannot be determined. The acaulosporoid spores from the Rhynie chert document that this spore type was in existence already ∼400 mya, and thus contribute to a more complete understanding of the evolutionary history of the Glomeromycota. This discovery pushes back the evolutionary origin of all main glomeromycotan groups, revealing that they had evolved before rooted land plants had emerged.

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“…Difficulties persist in the identification and nomenclature of mycobionts, requiring a combination of morphological, physiological and molecular approaches (Jorgensen, 1991 ;Gargas & Taylor, 1992 ;Bridge & Hawksworth, 1998 ;Nimis, 1998 ;Rambold et al, 1998). †See Schussler et al (1994) and Gehrig et al (1996). ‡See Villareal (1992), Schenk (1992) and Carpenter et al (1999).…”

Section: Hosts and Their Rolementioning

confidence: 99%

Tansley Review No. 116

2000

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Summary 449 I. INTRODUCTION 450 II. THE PARTNERS 451 1. Cyanobionts and their role 451 2. Hosts and their role 453 3. Location of cyanobionts in their hosts 455 III. INITIATION AND DEVELOPMENT OF SYMBIOSES 458 1. Initiation of symbioses 458 2. Geosiphon pyriforme 458 3. Cyanolichens 459 4. Liverworts and hornworts 460 5. Azolla 460 6. Cycads 461 7. Gunnera 461 IV. THE SYMBIOSES 462 1. Geographical distribution and ecological significance 462 2. Benefits to the partners 462 (a) Benefits to the cyanobionts 462 (b) Benefits to the hosts 463 3. Duration and stability 463 4. Mode of transmission and perpetuation 463 5. Recognition between the partners 464 6. Specificity and diversity 464 7. Symbiosis‐related genes 465 8. Modifications of the cyanobiont 466 (a) Growth and morphology 466 (b) Photosynthesis and carbon metabolism 467 (c) Glutamine synthetase 467 (d) Heterocysts 469 (e) N2fixation 470 9. Nutrient exchange 471 (a) Carbon 471 (b) Nitrogen 472 V. EVOLUTIONARY ASPECTS 472 VI. ARTIFICIAL SYMBIOSES 474 VII. FUTURE OUTLOOK AND PERSPECTIVES 475 1. Cryptic symbioses 476 2. Developmental profile of symbiotic tissues 476 3. Sensing and signalling 476 4. Genetic aspects 476 5. Physiological and biochemical aspects of nutrient exchange 477 6. Microaerobiosis 477 7. Potential applications 477 Acknowledgements 477 References 477 Cyanobacteria are an ancient, morphologically diverse group of prokaryotes with an oxygenic photosynthesis. Many cyanobacteria also possess the ability to fix N2. Although well suited to an independent existence in nature, some cyanobacteria occur in symbiosis with a wide range of hosts (protists, animals and plants). Among plants, such symbioses have independently evolved in phylogenetically diverse genera belonging to the algae, fungi, bryophytes, pteridophytes, gymnosperms and angiosperms. These are N2‐fixing symbioses involving heterocystous cyanobacteria, particularly Nostoc, as cyanobionts (cyanobacterial partners). A given host species associates with only a particular cyanobiont genus but such specificity does not extend to the strain level. The cyanobiont is located under a microaerobic environment in a variety of host organs and tissues (bladder, thalli and cephalodia in fungi; cavities in gametophytes of hornworts and liverworts or fronds of the Azolla sporophyte; coralloid roots in cycads; stem glands in Gunnera). Except for fungi, the hosts form these structures ahead of the cyanobiont infection. The symbiosis lasts for one generation except in Azolla and diatoms, in which it is perpetuated from generation to generation. Within each generation, multiple fresh infections occur as new symbiotic tissues and organs develop. The symbioses are stable over a wide range of environmental conditions, and sensing–signalling between partners ensures their synchronized growth and development. The cyanobiont population is kept constant in relation to the host biomass through controlled initiation and infection, nutrient supply and cell division. In most cases, the partners have remaine...

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Geosiphon pyriforme, an Endosymbiotic Association of Fungus and Cyanobacteria: the Spore Structure Resembles that of Arbuscular Mycorrhizal (AM) Fungi

Cited by 85 publications

References 36 publications

Element storage in spores of Gigaspora margarita Becker & Hall measured by electron energy loss spectroscopy (EELS)

Element storage in spores of Gigaspora margarita Becker & Hall measured by electron energy loss spectroscopy (EELS)

Acaulosporoid glomeromycotan spores with a germination shield from the 400-million-year-old Rhynie chert

Tansley Review No. 116

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