scholarly journals Chiral monoterpenes reveal forest emission mechanisms and drought responses

2021 ◽  
Author(s):  
Jonathan Williams ◽  
Joseph Byron ◽  
Juergen Kreuzwieser ◽  
Gemma Purser ◽  
Joost van Haren ◽  
...  
Keyword(s):  
Tropical Rainforest ◽  
De Novo ◽  
Mirror Image ◽  
Cloud Formation ◽  
Isotopic Labelling ◽  
Ecological Functions ◽  
Monoterpene Emission ◽  
Atmospheric Feedbacks ◽  
Photo Chemistry ◽  
Storage Pools

Abstract Monoterpenes exist in mirror image forms called enantiomers, but their individual formation pathways in plants and ecological functions are poorly understood, as enantiomers are usually measured and modelled together. Here we present enantiomerically separated atmospheric monoterpene and isoprene data from an enclosed tropical rainforest ecosystem without photo-chemistry during a four-month controlled drought and rewetting experiment. Surprisingly, the enantiomers showed distinct diel emission peaks, which responded differently to progressive drying. Isotopic labelling established that vegetation emitted (-)-α-pinene mainly de novo while (+)-α-pinene was emitted from storage pools. As drought stress increased, (-)-α-pinene emis-sions shifted to storage pools, which are released later in the day, favouring cloud formation. The α-pinene enantiomers each correlated better with other monoterpenes than with each other, indicating different enzymatic controls. These results show that enantiomeric distribution is key to understanding the processes driving monoterpene emission from ecosystems and to predict-ing atmospheric feedbacks in response to climate change.

scholarly journals Role of de novo biosynthesis in ecosystem scale monoterpene emissions from a boreal Scots pine forest

2011 ◽  
Vol 8 (8) ◽  
pp. 2247-2255 ◽  
Author(s):  
R. Taipale ◽  
M. K. Kajos ◽  
J. Patokoski ◽  
P. Rantala ◽  
T. M. Ruuskanen ◽  
...  
Keyword(s):  
Scots Pine ◽  
De Novo ◽  
Proton Transfer Reaction ◽  
Eddy Covariance Method ◽  
De Novo Biosynthesis ◽  
Monoterpene Biosynthesis ◽  
Monthly Changes ◽  
Scots Pine Forest ◽  
Storage Pools

Abstract. Monoterpene emissions from Scots pine have traditionally been assumed to originate as evaporation from specialized storage pools. More recently, the significance of de novo emissions, originating directly from monoterpene biosynthesis, has been recognized. To study the role of biosynthesis at the ecosystem scale, we measured monoterpene emissions from a Scots pine dominated forest in southern Finland using the disjunct eddy covariance method combined with proton transfer reaction mass spectrometry. The interpretation of the measurements was based on a correlation analysis and a hybrid emission algorithm describing both de novo and pool emissions. During the measurement period May–August 2007, the monthly medians of daytime emissions were 200, 290, 180, and 200 μg m−2 h−1. The emissions were partly light dependent, probably due to de novo biosynthesis. The emission potential for both de novo and pool emissions exhibited a decreasing summertime trend. The ratio of the de novo emission potential to the total emission potential varied between 30 % and 46 %. Although the monthly changes were not significant, the ratio always differed statistically from zero, suggesting that the role of de novo biosynthesis was observable. Given the uncertainties in this study, we conclude that more accurate estimates of the contribution of de novo emissions are required for improving monoterpene emission algorithms for Scots pine dominated forests.

scholarly journals A Case of Multiple Intracranial Aneurysms with Unruptured Associated Aneurysms and Newly Developed Ruptured Aneurysm

2001 ◽  
Vol 7 (3) ◽  
pp. 259-262 ◽  
Author(s):  
V.K. Jayakrishnan ◽  
G. Rodesch ◽  
H. Alvarez ◽  
P. Lasjaunias
Keyword(s):  
Kidney Disease ◽  
Intracranial Aneurysms ◽  
De Novo ◽  
Current Trend ◽  
Mirror Image ◽  
Polycystic Kidney ◽  
Unruptured Aneurysms ◽  
De Novo Aneurysm ◽  
The Right ◽  
Image Type

We report a case of mirror aneurysms at the middle cerebral artery bifurcation with rupture on the left side. After six years, the patient had subarachnoid haemorrhage from a de novo aneurysm which developed separate from but adjacent to the already present aneurysm on the right side. The mechanism of development of multiple aneurysms, especially of the mirror-image type cannot be explained based only on haemodynamic factors and congenital segmental arterial vulnerability which is generalised than focal is highly likely. The sequence of development of aneurysms in this patient along with existing knowledge regarding rupture of aneurysms in conditions like polycystic kidney disease raise questions about the current trend of treating all patients with coincidental, unruptured aneurysms as they may never bleed from such aneurysms but could still be at risk of SAH from newly developing aneurysms.

scholarly journals Extracellular Granzyme K Modulates Angiogenesis by Regulating Soluble VEGFR1 Release From Endothelial Cells

2021 ◽  
Vol 11 ◽  
Author(s):  
Shuang Li ◽  
Christian G. M. van Dijk ◽  
Jan Meeldijk ◽  
Helena M. Kok ◽  
Isabelle Blommestein ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Serine Proteases ◽  
De Novo ◽  
Target Cells ◽  
Protein Levels ◽  
Mrna And Protein Expression ◽  
Membrane Bound ◽  
Release Potential ◽  
Soluble Vegfr1 ◽  
Storage Pools

Angiogenesis is crucial for normal development and homeostasis, but also plays a role in many diseases including cardiovascular diseases, autoimmune diseases, and cancer. Granzymes are serine proteases stored in the granules of cytotoxic cells, and have predominantly been studied for their pro-apoptotic role upon delivery in target cells. A growing body of evidence is emerging that granzymes also display extracellular functions, which largely remain unknown. In the present study, we show that extracellular granzyme K (GrK) inhibits angiogenesis and triggers endothelial cells to release soluble VEGFR1 (sVEGFR1), a decoy receptor that inhibits angiogenesis by sequestering VEGF-A. GrK does not cleave off membrane-bound VEGFR1 from the cell surface, does not release potential sVEGFR1 storage pools from endothelial cells, and does not trigger sVEGFR1 release via protease activating receptor-1 (PAR-1) activation. GrK induces de novo sVEGFR1 mRNA and protein expression and subsequent release of sVEGFR1 from endothelial cells. GrK protein is detectable in human colorectal tumor tissue and its levels positively correlate with sVEGFR1 protein levels and negatively correlate with T4 intratumoral angiogenesis and tumor size. In conclusion, extracellular GrK can inhibit angiogenesis via secretion of sVEGFR1 from endothelial cells, thereby sequestering VEGF-A and impairing VEGFR signaling. Our observation that GrK positively correlates with sVEGFR1 and negatively correlates with angiogenesis in colorectal cancer, suggest that the GrK-sVEGFR1-angiogenesis axis may be a valid target for development of novel anti-angiogenic therapies in cancer.

scholarly journals Detection of Two Highly Diverse Peribunyaviruses in Mosquitoes from Palenque, Mexico

Viruses ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 832 ◽  
Author(s):  
Anne Kopp ◽  
Alexandra Hübner ◽  
Florian Zirkel ◽  
Daniel Hobelsberger ◽  
Alejandro Estrada ◽  
...  
Keyword(s):  
De Novo Assembly ◽  
Mammalian Cells ◽  
New Genus ◽  
Tropical Rainforest ◽  
Virus Isolation ◽  
De Novo ◽  
Blood Feeding ◽  
Transmission Cycle ◽  
Mosquito Cells ◽  
Duck Species

The Peribunyaviridae family contains the genera Orthobunyavirus, Herbevirus, Pacuvirus, and Shangavirus. Orthobunyaviruses and pacuviruses are mainly transmitted by blood-feeding insects and infect a variety of vertebrates whereas herbeviruses and shangaviruses have a host range restricted to insects. Here, we tested mosquitoes from a tropical rainforest in Mexico for infections with peribunyaviruses. We identified and characterized two previously unknown viruses, designated Baakal virus (BKAV) and Lakamha virus (LAKV). Sequencing and de novo assembly of the entire BKAV and LAKV genomes revealed that BKAV is an orthobunyavirus and LAKV is likely to belong to a new genus. LAKV was almost equidistant to the established peribunyavirus genera and branched as a deep rooting solitary lineage basal to herbeviruses. Virus isolation attempts of LAKV failed. BKAV is most closely related to the bird-associated orthobunyaviruses Koongol virus and Gamboa virus. BKAV was successfully isolated in mosquito cells but did not replicate in common mammalian cells from various species and organs. Also cells derived from chicken were not susceptible. Interestingly, BKAV can infect cells derived from a duck species that is endemic in the region where the BKAV-positive mosquito was collected. These results suggest a narrow host specificity and maintenance in a mosquito–bird transmission cycle.

scholarly journals Metagenomic Insights into the Metabolic and Ecological Functions of Abundant Deep-Sea Hydrothermal Vent DPANN Archaea

2021 ◽  
Vol 87 (9) ◽  
Author(s):  
Ruining Cai ◽  
Jing Zhang ◽  
Rui Liu ◽  
Chaomin Sun
Keyword(s):  
Genome Size ◽  
Deep Sea ◽  
Hydrothermal Vent ◽  
De Novo ◽  
Biological Processes ◽  
Acid Biosynthesis ◽  
Ecological Functions ◽  
Ecological Roles ◽  
Special Environment ◽  
Hydrothermal Environments

ABSTRACT Due to their unique metabolism and important ecological roles, deep-sea hydrothermal archaea have attracted great scientific interest. Among these archaea, DPANN superphylum archaea are widely distributed in hydrothermal vent environments. However, DPANN metabolism and ecology remain largely unknown. In this study, we assembled 20 DPANN genomes among 43 reconstructed genomes obtained from deep-sea hydrothermal vent sediments. Phylogenetic analysis suggests 6 phyla, comprised of Aenigmarchaeota, Diapherotrites, Nanoarchaeota, Pacearchaeota, Woesearchaeota, and a new candidate phylum we have designated Kexuearchaeota. These are included in the 20 DPANN archaeal members, indicating their broad diversity in this special environment. Analyses of their metabolism reveal deficiencies due to their reduced genome size, including gluconeogenesis and de novo nucleotide and amino acid biosynthesis. However, DPANN archaea possess alternate strategies to address these deficiencies. DPANN archaea also have the potential to assimilate nitrogen and sulfur compounds, indicating an important ecological role in the hydrothermal vent system. IMPORTANCE DPANN archaea show high distribution in the hydrothermal system, although they display small genome size and some incomplete biological processes. Exploring their metabolism is helpful to understand how such small forms of life adapt to this unique environment and what ecological roles they play. In this study, we obtained 20 high-quality metagenome-assembled genomes (MAGs) corresponding to 6 phyla of the DPANN group (Aenigmarchaeota, Diapherotrites, Nanoarchaeota, Pacearchaeota, Woesearchaeota, and a new candidate phylum designated Kexuearchaeota). Further metagenomic analyses provided insights on the metabolism and ecological functions of DPANN archaea to adapt to deep-sea hydrothermal environments. Our study contributes to a deeper understanding of their special lifestyles and should provide clues to cultivate this important archaeal group in the future.

scholarly journals Xenoprotein engineering via synthetic libraries

2018 ◽  
Vol 115 (23) ◽  
pp. E5298-E5306 ◽  
Author(s):  
Zachary P. Gates ◽  
Alexander A. Vinogradov ◽  
Anthony J. Quartararo ◽  
Anupam Bandyopadhyay ◽  
Zi-Ning Choo ◽  
...  
Keyword(s):  
Total Synthesis ◽  
De Novo ◽  
Surface Display ◽  
Cell Surface Display ◽  
Magnetic Bead ◽  
Mirror Image ◽  
Distinct Advantage ◽  
Protein Library ◽  
Magnetic Bead Enrichment ◽  
Protein Libraries

Chemical methods have enabled the total synthesis of protein molecules of ever-increasing size and complexity. However, methods to engineer synthetic proteins comprising noncanonical amino acids have not kept pace, even though this capability would be a distinct advantage of the total synthesis approach to protein science. In this work, we report a platform for protein engineering based on the screening of synthetic one-bead one-compound protein libraries. Screening throughput approaching that of cell surface display was achieved by a combination of magnetic bead enrichment, flow cytometry analysis of on-bead screens, and high-throughput MS/MS-based sequencing of identified active compounds. Direct screening of a synthetic protein library by these methods resulted in the de novo discovery of mirror-image miniprotein-based binders to a ∼150-kDa protein target, a task that would be difficult or impossible by other means.

scholarly journals Mirror image hydrocarbons from Tropical and Boreal forests

2006 ◽  
Vol 6 (5) ◽  
pp. 9583-9602
Author(s):  
J. Williams ◽  
N. Yassaa ◽  
S. Bartenbach ◽  
J. Lelieveld
Keyword(s):  
South America ◽  
Boreal Forest ◽  
Tropical Forest ◽  
Boreal Forests ◽  
Forest Ecosystems ◽  
Tropical Rainforest ◽  
Ambient Air ◽  
Mirror Image ◽  
Northern Europe ◽  
Large Excess

Abstract. Monoterpenes, emitted in large quantities by trees to attract pollinators and repel herbivores, can exist in mirror image forms called enantiomers. In this study such enantiomeric pairs have been measured in ambient air over extensive forest ecosystems in South America and northern Europe. For the dominant monoterpene, α-pinene, the (–)-form was measured in large excess over the (+)-form over the Tropical rainforest, whereas the reverse was observed over the Boreal forest. Interestingly, over the Tropical forest (–)-α-pinene did not correlate with its own enantiomer, but correlated well with isoprene. The results indicate a remarkable ecosystem scale enantiomeric fingerprint and a nexus between the biosphere and atmosphere.

scholarly journals <sup>13</sup>C labelling study of constitutive and stress-induced terpenoide missions from Norway spruce and Scots pine

2017 ◽  
Author(s):  
Cheng Wu ◽  
Iida Pullinen ◽  
Stefanie Andres ◽  
Astrid Kiendler-Scharr ◽  
Einhard Kleist ◽  
...  
Keyword(s):  
Norway Spruce ◽  
Scots Pine ◽  
Atmospheric Chemistry ◽  
De Novo ◽  
Carbon Sources ◽  
Turnover Time ◽  
Co2 Uptake ◽  
Terpenoid Biosynthesis ◽  
Mva Pathway ◽  
Storage Pools

Abstract. Due to their large source strengths, biogenic volatile organic compounds (BVOCs) are important for atmospheric chemistry. Terpenoids, mainly consisting of isoprene, monoterpenes and sesquiterpenes, are the dominant BVOC class. There are two general mechanisms for their emissions: emissions directly from de novo biosynthesis (de novo emissions) and emissions from organs wherein the terpenoids are stored (pool emissions). While isoprene emissions are pure de novo emissions, the mechanism for monoterpene and sesquiterpene emissions is not always distinct. In particular, conifers have large storage pools and both mechanisms may contribute to the emissions. To obtain more insight into the mechanisms of the terpenoid emissions from Eurasian conifers, we conducted 13CO2 and 13C-glucose labelling studies with Norway spruce (Picea abies L.) and Scots pine (Pinus sylvestris L.). The results from the labelling experiments were further compared to diurnal modulations measured for the emission fluxes of the respective terpenoids, as well as to their release from reservoirs in needles and bark tissue. The comparison allowed the following comprehensive statements for the investigated conifers. Consistent to other studies, we found that constitutive monoterpene emissions mainly originate from storage pools but with compound-specific fractions of de novo emissions. In contrast, stress-induced monoterpene and sesquiterpene emissions are entirely of de novo nature. We also found at least three different carbon sources for monoterpene and sesquiterpene biosynthesis. These sources differ with respect to the timescale after which the recently assimilated carbon reappears in the emitted terpenoids. Carbon directly obtained from assimilated has a short turnover time of few hours, while carbon from other alternative carbon sources has intermediate turnover times of few days and even longer. Terpenoid biosynthesis is not restricted to the presence of light and the carbon for terpenoid biosynthesis can be delivered from the alternative carbon sources. In particular for sesquiterpenes, there can be substantial de novo emissions in darkness reaching up to around 60 % of the daytime emissions. The use of the alternative carbon sources for sesquiterpene synthesis is probably linked to the mevalonic acid (MVA) pathway. The higher the contribution of the MVA pathway to terpenoid synthesis, the higher is the nocturnal de novo emission. In general, the emission mechanisms of monoterpene and sesquiterpene are more complex than assumed so far. Besides pools for terpenoids themselves, there are also pools for terpenoids precursors. Terpenoid synthesis from alternative carbon sources leads to nighttime emissions and hence the amplitude of diurnal modulations of terpenoid emissions may be determined by an overlap of three mechanisms involved: emissions from storage pools, emissions in parallel to CO2 uptake and emissions from alternative carbon sources.

Tetramelic mirror-image polydactyly and a de novo balanced translocation between 2p23.3 and 14q13

1997 ◽  
Vol 68 (1) ◽  
pp. 70-73 ◽  
Author(s):  
Kyoung Chang Kim ◽  
Keiko Wakui ◽  
Akira Yamagishi ◽  
Tsutomu Ohno ◽  
Masato Sato ◽  
...  
Keyword(s):  
De Novo ◽  
Mirror Image ◽  
Balanced Translocation

scholarly journals Termites mitigate the effects of drought in tropical rainforest

Science ◽  
2019 ◽  
Vol 363 (6423) ◽  
pp. 174-177 ◽  
Author(s):  
L. A. Ashton ◽  
H. M. Griffiths ◽  
C. L. Parr ◽  
T. A. Evans ◽  
R. K. Didham ◽  
...  
Keyword(s):  
Large Scale ◽  
Tropical Rainforest ◽  
Seedling Survival ◽  
Survival Rates ◽  
Soil Nutrient ◽  
Tropical Rainforests ◽  
Negative Consequences ◽  
Ecological Functions ◽  
Soil Nutrient Heterogeneity ◽  
Effects Of Drought

Termites perform key ecological functions in tropical ecosystems, are strongly affected by variation in rainfall, and respond negatively to habitat disturbance. However, it is not known how the projected increase in frequency and severity of droughts in tropical rainforests will alter termite communities and the maintenance of ecosystem processes. Using a large-scale termite suppression experiment, we found that termite activity and abundance increased during drought in a Bornean forest. This increase resulted in accelerated litter decomposition, elevated soil moisture, greater soil nutrient heterogeneity, and higher seedling survival rates during the extreme El Niño drought of 2015–2016. Our work shows how an invertebrate group enhances ecosystem resistance to drought, providing evidence that the dual stressors of climate change and anthropogenic shifts in biotic communities will have various negative consequences for the maintenance of rainforest ecosystems.

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