Ultrastructure of Stigonema in the Cephalodia of Stereocaulon Paschale

1983 ◽  
Vol 15 (2) ◽  
pp. 181-190 ◽  
Author(s):  
Birgitta Bergman ◽  
Kerstin Huss-Danell
Keyword(s):  
Seasonal Variation ◽  
Metabolic Activity ◽  
Lipid Droplets ◽  
Nitrogenase Activity ◽  
Late Winter ◽  
Nitrogen Storage ◽  
Bare Ground ◽  
Carbon And Nitrogen ◽  
Dividing Cells ◽  
Storage Products

AbstractSince seasonal variation in the nitrogenase activity of Stereocaulon paschale is known, the infrastructure of Stigonema in the cephalodia was examined in thalli of S. paschale collected from under snow in late winter, and from bare ground in late autumn. In contrast to the Stigonema cells of the autumn material, those of the winter material were relatively devoid of osmiophilic (lipid) droplets and polyglucoside and cyanophycin granules, reflecting that carbon and nitrogen storage products had been metabolized. In young cephalodia dividing cells were common, while in old cephalodia degenerating cells predominated. Haustoria appeared in material collected in both seasons, but may be limited to degenerating Stigonema cells or to Stigonema cells with a low metabolic activity.

scholarly journals Subcellular Investigation of Photosynthesis-Driven Carbon Assimilation in the Symbiotic Reef Coral Pocillopora damicornis

mBio ◽  
2015 ◽  
Vol 6 (1) ◽  
Author(s):  
Christophe Kopp ◽  
Isabelle Domart-Coulon ◽  
Stephane Escrig ◽  
Bruno M. Humbel ◽  
Michel Hignette ◽  
...  
Keyword(s):  
Lipid Droplets ◽  
Secondary Ion Mass Spectrometry ◽  
Reef Coral ◽  
Carbon Assimilation ◽  
Isotopic Labeling ◽  
Cellular Level ◽  
Coral Tissue ◽  
Pocillopora Damicornis ◽  
Carbon And Nitrogen ◽  
Transmission Electron

ABSTRACT  Reef-building corals form essential, mutualistic endosymbiotic associations with photosynthetic Symbiodinium dinoflagellates, providing their animal host partner with photosynthetically derived nutrients that allow the coral to thrive in oligotrophic waters. However, little is known about the dynamics of these nutritional interactions at the (sub)cellular level. Here, we visualize with submicrometer spatial resolution the carbon and nitrogen fluxes in the intact coral-dinoflagellate association from the reef coral Pocillopora damicornis by combining nanoscale secondary ion mass spectrometry (NanoSIMS) and transmission electron microscopy with pulse-chase isotopic labeling using [13C]bicarbonate and [15N]nitrate. This allows us to observe that (i) through light-driven photosynthesis, dinoflagellates rapidly assimilate inorganic bicarbonate and nitrate, temporarily storing carbon within lipid droplets and starch granules for remobilization in nighttime, along with carbon and nitrogen incorporation into other subcellular compartments for dinoflagellate growth and maintenance, (ii) carbon-containing photosynthates are translocated to all four coral tissue layers, where they accumulate after only 15 min in coral lipid droplets from the oral gastroderm and within 6 h in glycogen granules from the oral epiderm, and (iii) the translocation of nitrogen-containing photosynthates is delayed by 3 h. IMPORTANCE  Our results provide detailed in situ subcellular visualization of the fate of photosynthesis-derived carbon and nitrogen in the coral-dinoflagellate endosymbiosis. We directly demonstrate that lipid droplets and glycogen granules in the coral tissue are sinks for translocated carbon photosynthates by dinoflagellates and confirm their key role in the trophic interactions within the coral-dinoflagellate association.

Modeling the effects of fire and climate change on carbon and nitrogen storage in lodgepole pine (Pinus contorta) stands

2009 ◽  
Vol 15 (3) ◽  
pp. 535-548 ◽  
Author(s):  
E. A. H. SMITHWICK ◽  
M. G. RYAN ◽  
D. M. KASHIAN ◽  
W. H. ROMME ◽  
D. B. TINKER ◽  
...  
Keyword(s):  
Climate Change ◽  
Pinus Contorta ◽  
Lodgepole Pine ◽  
Nitrogen Storage ◽  
Carbon And Nitrogen

Grazing effects on fungal root symbionts and carbon and nitrogen storage in a shortgrass steppe in Central Mexico

2008 ◽  
Vol 72 (4) ◽  
pp. 546-556 ◽  
Author(s):  
E. Medina-Roldán ◽  
J.T. Arredondo ◽  
E. Huber-Sannwald ◽  
L. Chapa-Vargas ◽  
V. Olalde-Portugal
Keyword(s):  
Shortgrass Steppe ◽  
Central Mexico ◽  
Nitrogen Storage ◽  
Carbon And Nitrogen ◽  
Grazing Effects ◽  
Root Symbionts

Soil Carbon and Nitrogen Storage in Upper Montane Riparian Meadows

Ecosystems ◽  
2011 ◽  
Vol 14 (8) ◽  
pp. 1217-1231 ◽  
Author(s):  
Jay B. Norton ◽  
Laura J. Jungst ◽  
Urszula Norton ◽  
Hayley R. Olsen ◽  
Kenneth W. Tate ◽  
...  
Keyword(s):  
Soil Carbon ◽  
Nitrogen Storage ◽  
Carbon And Nitrogen ◽  
Soil Carbon And Nitrogen ◽  
Riparian Meadows

scholarly journals Contrasting recruitment seasonality of sea urchin species in Gran Canaria, Canary Islands (eastern Atlantic)

2014 ◽  
Vol 15 (3) ◽  
pp. 475 ◽  
Author(s):  
S. GARCIA-SANZ ◽  
P. G. NAVARRO ◽  
F. TUYA
Keyword(s):  
Community Structure ◽  
Seasonal Variation ◽  
Sea Urchin ◽  
Sea Urchins ◽  
Late Summer ◽  
Paracentrotus Lividus ◽  
Abundant Species ◽  
Late Winter ◽  
Gran Canaria ◽  
Arbacia Lixula

Despite sea-urchins can play an important role affecting the community structure of subtidal bottoms, factors controlling the dynamics of sea-urchin populations are still poorly understood. We assessed the seasonal variation in recruitment of three sea-urchin species (Diadema africanum, Paracentrotus lividus and Arbacia lixula) at Gran Canaria Island (eastern Atlantic) via monthly deployment of artificial collectors throughout an entire annual cycle on each of four adjacent habitat patches (seagrasses, sandy patches, ‘urchin-grazed’ barrens and macroalgal-dominated beds) within a shallow coastal landscape. Paracentrotus lividus and A. lixula had exclusively one main recruitment peak in late winter-spring. Diadema africanum recruitment was also seasonal, but recruits appeared in late summer-autumn, particularly on ‘urchin-grazed’ barrens with large abundances of adult conspecifics. In conclusion, this study has demonstrated non-overlapping seasonal recruitment patterns of the less abundant species (P. lividus and A. lixula) with the most conspicuous species (D. africanum) in the study area.

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