Cyst formation in tubificidae (Naidinae) and opistocystidae (Annelida, Oligochaeta) as an adaptive strategy for drought tolerance in fluvial wetlands of the Paraná River, Argentina

Wetlands ◽  
10.1672/23 ◽  
2005 ◽  
Vol 25 (2) ◽  
pp. 488-494 ◽  
Author(s):  
Luciana Montalto ◽  
Mercedes Marchese
Keyword(s):  
Drought Tolerance ◽  
Adaptive Strategy ◽  
Cyst Formation ◽  
Paraná River ◽  
Parana River ◽  
Fluvial Wetlands

scholarly journals Transcriptome and metabolome analyses of cold and darkness-induced pellicle cysts of Scrippsiella trochoidea

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Xin Guo ◽  
Zhaohui Wang ◽  
Lei Liu ◽  
Yang Li
Keyword(s):  
Signal Transduction ◽  
Sexual Reproduction ◽  
Harmful Algal Bloom ◽  
Transcriptional Response ◽  
Tca Cycle ◽  
Adaptive Strategy ◽  
Cyst Formation ◽  
Metabolite Profile ◽  
Scrippsiella Trochoidea ◽  
Regulatory Processes

Abstract Background Dinoflagellates are a group of unicellular organisms that are a major component of aquatic eukaryotes and important contributors to marine primary production. Nevertheless, many dinoflagellates are considered harmful algal bloom (HAB) species due to their detrimental environmental and human health impacts. Cyst formation is widely perceived as an adaptive strategy of cyst-forming dinoflagellates in response to adverse environmental conditions. Dinoflagellate cysts play critical roles in bloom dynamics. However, our insight into the underlying molecular basis of encystment is still limited. To investigate the molecular processes regulating encystment in dinoflagellates, transcriptome and metabolome investigations were performed on cold and darkness-induced pellicle cysts of Scrippsiella trochoidea. Results No significant transcriptional response was observed at 2 h; however, massive transcriptome and metabolome reprogramming occurred at 5 h and in pellicle cysts. The gene-to-metabolite network demonstrated that the initial transformation from vegetative cells into pellicle cysts was highly energy demanding through the activation of catabolism, including glycolysis, β-oxidation, TCA cycle and oxidative phosphorylation, to cope with cold-darkness-induced stress. However, after transformation into pellicle cysts, the metabolism was greatly reduced, and various sugars, polyunsaturated fatty acids and amino acids accumulated to prolong survival. The identification of 56 differentially expressed genes (DEGs) related to signal transduction indicated that S. trochoidea received a cold-darkness signal that activated multiple signal transduction pathways, leading to encystment. The elevated expression of genes encoding enzymes involved in ROS stress suggested that pellicle cysts respond to increased oxidative stress. Several cell cycle-related genes were repressed. Intriguingly, 11 DEGs associated with sexual reproduction suggested that pellicle cysts (or some portion thereof) may be a product of sexual reproduction. Conclusions This study provides the first transcriptome and metabolome analyses conducted during the encystment of S. trochoidea, an event that requires complex regulatory mechanisms and impacts on population dynamics. The results reveal comprehensive molecular regulatory processes underlying life cycle regulation in dinoflagellates involving signal transduction, gene expression and metabolite profile, which will improve our ability to understand and monitor dinoflagellate blooms.

NDVI patterns as indicator of morphodynamic activity in the middle Paraná River floodplain

Geomorphology ◽  
2016 ◽  
Vol 253 ◽  
pp. 146-158 ◽  
Author(s):  
Z.Y. Marchetti ◽  
P.G. Minotti ◽  
C.G. Ramonell ◽  
F. Schivo ◽  
P. Kandus
Keyword(s):  
Paraná River ◽  
River Floodplain ◽  
Parana River ◽  
Paraná River Floodplain ◽  
Middle Paraná

scholarly journals Evaluation of the Upper Paraná River discharge controlled by reservoirs

2009 ◽  
Vol 69 (2 suppl) ◽  
pp. 707-716 ◽  
Author(s):  
EE. Souza Filho
Keyword(s):  
Paraná River ◽  
River Level ◽  
Parana River ◽  
River Damming ◽  
Discharge Rates ◽  
Historical Series ◽  
Discharge Regime ◽  
Upper Paraná River ◽  
The Relationship ◽  
Different Levels

The building of large dams in the Upper Paraná River basin altered the discharge regime at the Porto São José River section. The discharge regime has been altered since 1972, but the changes intensified after the Porto Primavera damming, in late 1998. Considering that discharge control affects the relationship between channel and floodplain, this work aimed to evaluate the intensity of the discharge control that resulted from the operation of the Porto Primavera Dam. To achieve this objective, statistical analyses were carried out based on the Porto São José Fluviometric Station historical series of river level readings and discharge, between 1964 and 2007. Results showed that the average discharge increased from 1964 to 1981 and diminished after river damming. The increase of average discharge rates was followed by an increase of the duration of higher discharges at different levels of geomorphologic and limnological importance, and the reduction of average discharge during the last observed period was followed by a disproportionate decrease in the duration of the abovementioned discharges. Moreover, it is clear that the relationship between fluviometric level and fluvial discharge changed, which implies that a certain river level reading represents a higher discharge than necessary before river damming.

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