Studies on initiation and development of the partner association inGeosiphon pyriforme (K�tz.) v. Wettstein, a unique endocytobiotic system of a fungus (Glomales) and the cyanobacteriumNostoc punctiforme (K�tz.) Hariot

Mollenhauer, Dieter; Mollenhauer, Resi; Kluge, Manfred

doi:10.1007/bf01276630

Cited by 41 publications

(13 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Many symbiotic Nostoc isolates are referred to as Nostoc punctiforme (Zimmerman et al 1991(Zimmerman et al , 1992Mollenhauer et al 1996). The classification of N. punctiforme, type strain PCC 73102, is exclusively based on morphological criteria, cell size and the formation of a punctiforme stage (sheath-bound filaments with terminal heterocysts) in the life cycle of these cyanobacteria when grown on artificial medium.…”

Section: Introductionmentioning

confidence: 99%

Characterization by genotypic methods of symbiotic Nostoc strains isolated from five species of Gunnera

Rasmussen

Svenning

2001

Archives of Microbiology

View full text Add to dashboard Cite

The genetic diversity of ten symbiotic Nostoc strains isolated from different Gunnera species was investigated. The strains were analyzed using molecular methods with different taxonomic resolutions, including restriction fragment length polymorphisms (RFLP) of the PCR-amplified 16S ribosomal gene and the 16S-23S internal transcribed spacer (ITS) region combined with computer-assisted analyses. The functional gene hetR, assigned to heterocyst differentiation, was used for denaturing gradient gel electrophoresis. A high genetic diversity was observed among the isolates even in the conserved gene coding for the small ribosomal unit. No correlation was observed between clustering of cyanobacteria and the host species of Gunnera.

show abstract

Section: Introductionmentioning

confidence: 99%

Characterization by genotypic methods of symbiotic Nostoc strains isolated from five species of Gunnera

Rasmussen

Svenning

2001

Archives of Microbiology

View full text Add to dashboard Cite

show abstract

“…After some time, hormogonia become non‐motile and cells grow and develop a rounded shape. The transitional stage between the cessation of hormogonia motility and the start of new cell division activity is called ‘primordium’ (Mollenhauer, Mollenhauer & Kluge 1996). At this stage, terminal cells differentiate into heterocysts and a new glycan envelope forms.…”

Section: Introductionmentioning

confidence: 99%

Phycobiliprotein fluorescence of Nostoc punctiforme changes during the life cycle and chromatic adaptation: characterization by spectral confocal laser scanning microscopy and spectral unmixing

Wolf

Schüβler

2005

Plant Cell & Environment

View full text Add to dashboard Cite

Many cyanobacteria are highly adaptable to light quality, and many species undergo a complex life cycle. In this study we show that adaptive changes in the photosynthetic apparatus of cyanobacteria are not only caused by environmental, but also by developmental factors. Spectral confocal laser scanning microscopy (CLSM) was used to analyse in vivo the fluorescence spectra of the photosynthetic pigments chlorophyll a (Chl a ), allophycocyanin (APC), phycocyanin (PC) and phycoerythrin (PE) of two Nostoc punctiforme strains. Changes in pigment fluorescence emission occurred in different developmental stages. Strain 1:1-26 showed an emission maximum at 674 nm in motile hormogonia stages, whereas vegetative stages showed maxima at 658 and 575 nm. These changes were not caused by chromatic adaptation. In contrast, the second strain (1:1-26lg) showed distinct fluorescence spectra, pigment localization and clear chromatic adaptation in red light. When these properties are known, both strains can be easily distinguished by the spectral CLSM method, which also allows the localization of the pigments within single cells. To calculate the contribution of individual phycobiliproteins to the observed changes, fluorescence spectra were analysed by spectral unmixing. This allowed the mathematical estimation of fluorescence shares for the individual phycobiliproteins in different developmental stages and both before and after chromatic adaptation. It is concluded that care should be taken when characterizing cyanobacteria by differences in pigment fluorescence, because these differences are influenced not only by chromatic adaptation, but also developmental stages. Spectral CLSM offers a powerful method to study the phycobiliprotein composition in vivo .

show abstract

“…Reconstitution experiments in Geosiphon, liverworts and hornworts, and Gunnera show that these hosts are specific to Nostoc (Meeks, 1990 ;Bergman et al, 1992a ;Mollenhauer et al, 1996). Although not all strains of Nostoc are compatible, several compatible strains can form symbioses with one host.…”

Section: Specificity and Diversitymentioning

confidence: 99%

“…The hosts control the cyanobiont population by developing a restricted number and size of symbiotic tissues or organs as well as by controlling the nutrient supply to, and cell division of, the cyanobionts once inside the host. However, in very old symbiotic tissues, disintegration of partners is often noticed in lichens, Geosiphon bladders, Gunnera and cycads (Rai, 1990a ;Bergman et al, 1992a ;Ahern & Staff, 1994 ;Mollenhauer et al, 1996).…”

Section: Duration and Stabilitymentioning

confidence: 99%

Tansley Review No. 116

2000

View full text Add to dashboard Cite

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...

show abstract

Studies on initiation and development of the partner association inGeosiphon pyriforme (K�tz.) v. Wettstein, a unique endocytobiotic system of a fungus (Glomales) and the cyanobacteriumNostoc punctiforme (K�tz.) Hariot

Cited by 41 publications

References 12 publications

Characterization by genotypic methods of symbiotic Nostoc strains isolated from five species of Gunnera

Characterization by genotypic methods of symbiotic Nostoc strains isolated from five species of Gunnera

Phycobiliprotein fluorescence of Nostoc punctiforme changes during the life cycle and chromatic adaptation: characterization by spectral confocal laser scanning microscopy and spectral unmixing

Tansley Review No. 116

Contact Info

Product

Resources

About