scholarly journals Diel Transcriptional Oscillations of a Plastid Antiporter Reflect Increased Resilience of Thalassiosira pseudonana in Elevated CO2

2021 ◽  
Vol 8 ◽  
Author(s):  
Jacob J. Valenzuela ◽  
Justin Ashworth ◽  
Allison Cusick ◽  
Raffaela M. Abbriano ◽  
E. Virginia Armbrust ◽  
...  

Acidification of the ocean due to high atmospheric CO2 levels may increase the resilience of diatoms causing dramatic shifts in abiotic and biotic cycles with lasting implications on marine ecosystems. Here, we report a potential bioindicator of a shift in the resilience of a coastal and centric model diatom Thalassiosira pseudonana under elevated CO2. Specifically, we have discovered, through EGFP-tagging, a plastid membrane localized putative Na+(K+)/H+ antiporter that is significantly upregulated at >800 ppm CO2, with a potentially important role in maintaining pH homeostasis. Notably, transcript abundance of this antiporter gene was relatively low and constant over the diel cycle under contemporary CO2 conditions. In future acidified oceanic conditions, dramatic oscillation with >10-fold change between nighttime (high) and daytime (low) transcript abundances of the antiporter was associated with increased resilience of T. pseudonana. By analyzing metatranscriptomic data from the Tara Oceans project, we demonstrate that phylogenetically diverse diatoms express homologs of this antiporter across the globe. We propose that the differential between night- and daytime transcript levels of the antiporter could serve as a bioindicator of a shift in the resilience of diatoms in response to high CO2 conditions in marine environments.

2020 ◽  
Author(s):  
Jacob J. Valenzuela ◽  
Justin Ashworth ◽  
Allison Cusick ◽  
Raffaela M. Abbriano ◽  
E.Virginia Armbrust ◽  
...  

ABSTRACTAcidification of the ocean due to high atmospheric CO2 levels may increase the resilience of diatoms causing dramatic shifts in abiotic and biotic cycles with lasting implications on marine ecosystems. Here, we report a potential bioindicator of a shift in the resilience of a coastal and centric model diatom Thalassiosira pseudonana under elevated CO2. Specifically, we have discovered, through EGFP-tagging, a plastid membrane localized putative Na+(K+)/H+ antiporter that is significantly upregulated at > 800 ppm CO2, with a potentially important role in maintaining pH homeostasis. Notably, transcript abundance of this antiporter gene was relatively low and constant over the diel cycle under contemporary CO2 conditions. In future acidified oceanic conditions, dramatic oscillations of >10-fold change between nighttime (high) and daytime (low) in transcript abundances of the antiporter gene were associated with increased resilience of T. pseudonana. By analyzing metatranscriptomic data from the Tara Oceans project, we demonstrate that phylogenetically diverse diatoms express homologs of this antiporter across the globe. We propose that the differential between night- and daytime transcript levels of the antiporter could serve as a bioindicator of a shift in the resilience of diatoms in response to high CO2 conditions in marine environments.


2004 ◽  
Vol 31 (7) ◽  
pp. 721 ◽  
Author(s):  
Steven J. Sinclair ◽  
Richard Johnson ◽  
John D. Hamill

We determined the capacity of three Nicotiana (Solanaceae) species with very different alkaloid profiles (Nicotiana sylvestris Speg & Comes, Nicotiana alata Link & Otto and Nicotiana glauca Grah.) to increase their alkaloid contents in both leaf and root tissues following foliage damage. We also investigated the transcriptional responses of genes encoding enzymes important for alkaloid biosynthesis, namely quinolinate phosphoribosyltransferase (QPT), putrescine N-methyltransferase (PMT), ornithine decarboxylase (ODC) and the putative alkaloid biosynthetic gene A622. In response to wounding of foliage in the well studied ‘model’ species N. sylvestris, a rise, approximately 2-fold, in leaf nicotine levels was observed several days after a 4–5-fold increase in the transcript levels of all genes in the roots. In contrast, leaf tissues of the ornamental tobacco N. alata showed very low levels of any pyridine alkaloid, even when analysed 1 week after wounding, correlating with a general lack of transcript abundance representing any of these genes in leaves or roots following foliage damage. However, addition of methyl jasmonate to cultured roots of N. alata did produce elevated levels of nicotine and anatabine raising the possibility that components of the leaf–root wound signalling system in N. alata are different from those in N. sylvestris. Wounding of the tree tobacco N. glauca, was followed by a 2-fold increase in anabasine levels several days later. This increase followed a large rise in transcript levels of ODC, QPT and A622, though not PMT, in wounded leaves, but not in non-wounded leaves or roots. These data support the hypothesis that N. glauca is able to produce increased anabasine levels following wounding in its foliage, setting it apart from N. sylvestris where induced alkaloid production takes place in roots. We discuss the possibility that increased transcript levels detected by ODC and A622 probes play important roles in anabasine synthesis in N. glauca.


EDIS ◽  
1969 ◽  
Vol 2002 (8) ◽  
Author(s):  
Deborah J. Glauer

The new Florida 4-H Aquatic/Marine Ecosystems Leader’s Guide, is a part of the Environmental Education Framework, OUR NATURAL WORLD, This framework includes the basic premise that aquatic/marine environments are important in children’s lives, particularly to those children in Florida. The 4-H Aquatic/Marine Ecosystems program provides an opportunity for young people to practice a variety of life skills while learning subject matter.


2020 ◽  
pp. 73-82 ◽  
Author(s):  
Mark Little ◽  
Maria Isabel Rojas ◽  
Forest Rohwer

The roles of prophages in disease have mainly considered human pathogens, while their role in marine pathogens has only recently been considered. This chapter reviews the relevant literature on what is known of prophages in marine ecosystems and provides a meta-analysis of the abundance and function of prophages in marine pathogenic bacteria. According to these results, bacterial pathogens in marine environments contain a significantly higher abundance of prophage DNA in their genomes than host-associated bacteria, which are non-pathogenic. The authors also surveyed the genetic content of the prophages that were associated with known pathogens and compared their functions to non-pathogens. Their findings suggest that horizontally acquired prophage-encoded DNA may play a large role in the ecology and evolution of marine diseases


2019 ◽  
Vol 8 (2) ◽  
Author(s):  
Michael S. Guzman ◽  
Jonathan Chris Kuse ◽  
Natalia Santiago-Merced ◽  
Arpita Bose

Marichromatium species are photosynthetic gammaproteobacteria found in marine environments. Only two Marichromatium genomes are publicly available.


2020 ◽  
Vol 4 (s1) ◽  
pp. 12-12
Author(s):  
Margaret Zimmerman ◽  
Benard Ogola ◽  
Sarah Lindsey

OBJECTIVES/GOALS: Estrogen monotherapy in postmenopausal women can reduce kidney function, while dual therapy combining estrogen with a progestin improves renal health. Using the female Long Evans rat as a novel animal model of postmenopausal cardiovascular disease, we found similar results where estrogen worsens renal health while co-administration of medroxyprogesterone acetate (MPA) was protective. MPA cross-activates glucocorticoid receptors (GR), which are targeted clinically for their anti-inflammatory actions. Therefore, our goal was to determine if estrogen monotherapy induces renal damage by increasing inflammation, while dual therapy with MPA opposes inflammation by cross-activating GR. METHODS/STUDY POPULATION: Female Long Evans rats underwent OVX at 11 months of age and received a subcutaneous implant containing E2, E2+MPA or vehicle for 40 days. RESULTS/ANTICIPATED RESULTS: Coadministration of MPA prevented the E2-induced increase in proteinuria (Veh: 0.27 ± 0.07; E2: 3.53 ± 1.16; E2 + MPA: 1.20 ± 0.58 mg/mg creatinine; P = 0.03) and decline in glomerular filtration rate (Veh: 0.51 ± 0.02; E2: 0.24 ± 0.05; E2+MPA: 0.39 ± 0.05 ml/min; P < 0.01). Co-administration of MPA significantly increased renal GR transcript levels compared with E2 alone (Veh: 0.96 ± 0.02; E2: 0.94 ± 0.10; E2+MPA: 1.24 ± 0.04 fold change; P < 0.01). Inflammatory marker COX 2 renal transcript levels were significantly reduced by a similar degree in both mono and dual therapies compared with vehicle (Veh: 1.07 ± 0.06; E2: 0.81 ± 0.04; E2+MPA: 0.81 ± 0.04 fold change; P < 0.01). Neither TNF-alpha and IL-6 mRNA nor urinary beta-microglobulin levels (Veh: 1.71 ± 0.31; E2: 2.88 ± 0.78; E2+MPA: 3.07 ± 1.15 mg/day; ns) were altered. DISCUSSION/SIGNIFICANCE OF IMPACT: Our results show that the effect of E2 on renal pro-inflammatory markers was not altered by the addition of MPA despite the significant increase in renal GR levels. Therefore, the renoprotective effects of MPA in midlife hormone therapy may be independent of renal GR-mediated changes in the immune profile.


2015 ◽  
Vol 61 (4) ◽  
pp. 653-668 ◽  
Author(s):  
Anna V. Ivanina ◽  
Inna M. Sokolova

Abstract Changes in the global environment such as ocean acidification (OA) may interact with anthropogenic pollutants including trace metals threatening the integrity of marine ecosystems. We analyze recent studies on the interactive effects of OA and trace metals on marine organisms with a focus on the physiological basis of these interactions. Our analysis shows that the responses to elevated CO2 and metals are strongly dependent on the species, developmental stage, metal biochemistry and the degree of environmental hypercapnia, and cannot be directly predicted from the CO2-induced changes in metal solubility and speciation. The key physiological functions affected by both the OA and trace metal exposures involve acid-base regulation, protein turnover and mitochondrial bioenergetics, reflecting the sensitivity of the underlying molecular and cellular pathways to CO2and metals. Physiological interactions between elevated CO2 and metals may impact the organisms’ capacity to maintain acid-base homeostasis and reduce the amount of energy available for fitness-related functions such as growth, development and reproduction thereby affecting survival and performance of estuarine populations. Environmental hypercapnia may also affect the marine food webs by altering predator-prey interactions and the trophic transfer of metals in the food chain. However, our understanding of the degree to which these effects can impact the function and integrity of marine ecosystems is limited due the scarcity of the published research and its bias towards certain taxonomic groups. Future research priorities should include studies of metal x PCO2 interactions focusing on critical physiological functions (including acid-base, protein and energy homeostasis) in a greater range of ecologically and economically important marine species, as well as including the field populations naturally exposed (and potentially adapted) to different levels of metals and CO2 in their environments.


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