Rapid Toluene Mineralization by Aquifer Microorganisms at Adak, Alaska: Implications for Intrinsic Bioremediation in Cold Environments

Abstract Background Direct seeding is an efficient cultivation technique in rice. However, poor low temperature germinability (LTG) of modern rice cultivars limits its application. Identifying the genes associated with LTG and performing molecular breeding is the fundamental way to address this issue. However, few LTG QTLs have been fine mapped and cloned so far. Results In the present study, the LTG evaluation of 375 rice accessions selected from the Rice Diversity Panel 2 showed that there were large LTG variations within the population, and the LTG of Indica group was significantly higher than that of Japonica and Aus groups (p < 0.01). In total, eleven QTLs for LTG were identified through genome-wide association study (GWAS). Among them, qLTG_sRDP2–3/qLTG_JAP-3, qLTG_AUS-3 and qLTG_sRDP2–12 are first reported in the present study. The QTL on chromosome 10, qLTG_sRDP2–10a had the largest contribution to LTG variations in 375 rice accessions, and was further validated using single segment substitution line (SSSL). The presence of qLTG_sRDP2–10a could result in 59.8% increase in LTG under 15 °C low temperature. The expression analysis of the genes within qLTG_sRDP2–10a region indicated that LOC_Os10g22520 and LOC_Os10g22484 exhibited differential expression between the high and low LTG lines. Further sequence comparisons revealed that there were insertion and deletion sequence differences in the promoter and intron region of LOC_Os10g22520, and an about 6 kb variation at the 3′ end of LOC_Os10g22484 between the high and low LTG lines, suggesting that the sequence variations of the two genes could be the cause for their differential expression in high and low LTG lines. Conclusion Among the 11 QTLs identified in this study, qLTG_sRDP2–10a could also be detected in other three studies using different germplasm under different cold environments. Its large effect and stable expression make qLTG_sRDP2–10a particularly valuable in rice breeding. The two genes, LOC_Os10g22484 and LOC_Os10g22520, were considered as the candidate genes underlying qLTG_sRDP2–10a. Our results suggest that integrating GWAS and SSSL can facilitate identification of QTL for complex traits in rice. The identification of qLTG_sRDP2–10a and its candidate genes provide a promising source for gene cloning of LTG and molecular breeding for LTG in rice.

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Human performance research for military operations in extreme cold environments

Journal of Science and Medicine in Sport ◽

10.1016/j.jsams.2020.11.010 ◽

2020 ◽

Author(s):

Wendy Sullivan-Kwantes ◽

Francois Haman ◽

Boris R.M. Kingma ◽

Svein Martini ◽

Emilie Gautier-Wong ◽

...

Keyword(s):

Human Performance ◽

Military Operations ◽

Cold Environments ◽

Extreme Cold ◽

Performance Research

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Functional prediction of environmental variables using metabolic networks

Scientific Reports ◽

10.1038/s41598-021-91486-8 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Adèle Weber Zendrera ◽

Nataliya Sokolovska ◽

Hédi A. Soula

Keyword(s):

Machine Learning ◽

Growth Temperature ◽

Environmental Variables ◽

Metabolic Networks ◽

Machine Learning Techniques ◽

Underlying Structure ◽

Glutathione Biosynthesis ◽

Additional Information ◽

Cold Environments ◽

Novel Approach

AbstractIn this manuscript, we propose a novel approach to assess relationships between environment and metabolic networks. We used a comprehensive dataset of more than 5000 prokaryotic species from which we derived the metabolic networks. We compute the scope from the reconstructed graphs, which is the set of all metabolites and reactions that can potentially be synthesized when provided with external metabolites. We show using machine learning techniques that the scope is an excellent predictor of taxonomic and environmental variables, namely growth temperature, oxygen tolerance, and habitat. In the literature, metabolites and pathways are rarely used to discriminate species. We make use of the scope underlying structure—metabolites and pathways—to construct the predictive models, giving additional information on the important metabolic pathways needed to discriminate the species, which is often absent in other metabolic network properties. For example, in the particular case of growth temperature, glutathione biosynthesis pathways are specific to species growing in cold environments, whereas tungsten metabolism is specific to species in warm environments, as was hinted in current literature. From a machine learning perspective, the scope is able to reduce the dimension of our data, and can thus be considered as an interpretable graph embedding.

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Ice-active substances associated with Antarctic freshwater and terrestrial photosynthetic organisms

Antarctic Science ◽

10.1017/s0954102000000493 ◽

2000 ◽

Vol 12 (4) ◽

pp. 418-424 ◽

Cited By ~ 21

Author(s):

James A. Raymond ◽

Christian H. Fritsen

Keyword(s):

Molecular Weight ◽

North America ◽

Ice Crystals ◽

Dry Valleys ◽

Cyanobacterial Mats ◽

Cold Environments ◽

Photosynthetic Organisms ◽

Eukaryotic Algae ◽

Dialysis Membranes ◽

Active Substances

Macromolecular substances that cause pitting and other modifications of growing ice crystals were found to be associated with cyanobacterial mats, eukaryotic algae and mosses from Ross Island and the McMurdo Dry Valleys, Antarctica. Ice-pitting activities were largely retained by dialysis membranes with molecular weight cut-offs of up to 300 kDa. Unlike most aqueous solutes, the ice-active molecules were not excluded from the ice phase during freezing. The ice-pitting activities of each of the samples tested was destroyed by exposure to temperatures between 45 and 65°C, suggesting that they have a protein component. Ice-active substances were not found in cyanobacteria or mosses from temperate climates, but ice-activity was found to be associated with mosses from cold habitats in North America. Although the function of the ice-active substances is not known, their apparent confinement to cold environments suggests that they have a cryoprotective role.

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