Transposon mutagenesis of Nostoc sp. strain ATCC 29133, a filamentous cyanobacterium with multiple cellular differentiation alternatives

Cohen, Michael F.; Wallis, James G.; Campbell, Emily; Meeks, John C.

doi:10.1099/13500872-140-12-3233

Cited by 91 publications

(73 citation statements)

References 31 publications

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“…The mobilization of pDUCA7 into Nostoc sp. strain PCC 73102 was at least 50-fold improved (relative to that of pRL443) by the use of either pRK2013 or pRK2073 (a Km s Sp r derivative of pRK2013 [5,6]). Despite the compatibility between the origins of replication of conjugative plasmid pRK443 and cargo plasmid pRL489, the efficiencies of its transfer in Chroococcidiopsis sp.…”

Section: Discussionmentioning

confidence: 99%

Gene Transfer to the Desiccation-Tolerant Cyanobacterium Chroococcidiopsis

et al. 2001

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The coccoid cyanobacterium Chroococcidiopsis dominates microbial communities in the most extreme arid hot and cold deserts. These communities withstand constraints that result from multiple cycles of drying and wetting and/or prolonged desiccation, through mechanisms which remain poorly understood. Here we describe the first system for genetic manipulation of Chroococcidiopsis. Plasmids pDUCA7 and pRL489, based on the pDU1 replicon of Nostoc sp. strain PCC 7524, were transferred to different isolates of Chroococcidiopsis via conjugation and electroporation. This report provides the first evidence that pDU1 replicons can be maintained in cyanobacteria other than Nostoc and Anabaena. Following conjugation, both plasmids replicated in Chroococcidiopsis sp. strains 029, 057, and 123 but not in strains 171 and 584. Both plasmids were electroporated into strains 029 and 123 but not into strains 057, 171, and 584. Expression of P psbA -luxAB on pRL489 was visualized through in vivo luminescence. Efficiencies of conjugative transfer for pDUCA7 and pRL489 into Chroococcidiopsis sp. strain 029 were approximately 10 ؊2 and 10 ؊4 transconjugants per recipient cell, respectively. Conjugative transfer occurred with a lower efficiency into strains 057 and 123. Electrotransformation efficiencies of about 10 ؊4 electrotransformants per recipient cell were achieved with strains 029 and 123, using either pDUCA7 or pRL489. Extracellular deoxyribonucleases were associated with each of the five strains. Phylogenetic analysis, based upon the V6 to V8 variable regions of 16S rRNA, suggests that desert strains 057, 123, 171, and 029 are distinct from the type species strain Chroococcidiopsis thermalis PCC 7203. The high efficiency of conjugative transfer of Chroococcidiopsis sp. strain 029, from the Negev Desert, Israel, makes this a suitable experimental strain for genetic studies on desiccation tolerance.

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Section: Discussionmentioning

confidence: 99%

Gene Transfer to the Desiccation-Tolerant Cyanobacterium Chroococcidiopsis

et al. 2001

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“…Strains with a higher capacity for hormogonia differentiation show higher infectivity (Cohen et al, 1994). In Gunnera, the viscous mucilage secreted by stem glands contains HIF, a heat-labile protein of 12 kDa, which induces hormogonia formation in Nostoc strains (Rasmussen et al, 1994).…”

Section: Hosts and Their Rolementioning

confidence: 99%

“…Even non-N # -fixing mutants of compatible strains can infect, although they fail to support the host. Thus, N # fixation is not necessary for infection, but it is essential for the development of a functional symbiosis (Meeks, 1990 ;Cohen et al, 1994 ;Meeks et al, 1999).…”

Section: Liverworts and Hornwortsmentioning

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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“…These techniques were developed primarily in Anabaena sp. strain PCC 7120, and have recently been adapted for the genetic analysis of symbiotically competent cyanobacteria (Cohen et al, 1994). The genetic tools required for the molecular analysis of cyanobacteria have been reviewed recently (Haselkorn, 1991 ;Buikema & Haselkorn, 1993 ;Thiel, 1994 ;Wolk, 1996 ;Cohen et al, 1998).…”

Section: mentioning

confidence: 99%