The Experts below are selected from a list of 306 Experts worldwide ranked by ideXlab platform
Suhas Shinde - One of the best experts on this subject based on the ideXlab platform.
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Abiotic stress-induced oscillations in steady-state transcript levels of Group 3 LEA protein genes in the moss, Physcomitrella patens.
Plant signaling & behavior, 2012Co-Authors: Suhas Shinde, Rupali Shinde, Frances DowneyAbstract:The moss, Physcomitrella patens is a non-seed land plant belonging to early diverging lineages of land plants following colonization of land in the Ordovician Period in Earth’s history. Evidence suggests that mosses can be highly tolerant of abiotic stress. We showed previously that dehydration stress and abscisic acid treatments induced oscillations in steady-state levels of LEA (Late Embryogenesis Abundant) protein transcripts, and that removal of ABA resulted in rapid attenuation of oscillatory increases in transcript levels. Here, we show that other abiotic stresses like salt and osmotic stresses also induced oscillations in steady-state transcript levels and that the amplitudes of the oscillatory increases in steady-state transcript levels are reflective of the severity of the abiotic stress treatment. Together, our results suggest that oscillatory increases in transcript levels in response to abiotic stresses may be a general phenomenon in P. patens and that temporally dynamic increases in steady-state transcript levels may be important for adaptation to life in constantly fluctuating environmental conditions.
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Dehydration stress-induced oscillations in LEA protein transcripts involves abscisic acid in the moss, Physcomitrella patens
The New phytologist, 2012Co-Authors: Suhas Shinde, M. Nurul IslamAbstract:Summary •Physcomitrella patens is a bryophyte belonging to early diverging lineages of land plants following colonization of land in the Ordovician Period. Mosses are typically found in refugial habitats and can experience rapidly fluctuating environmental conditions. The acquisition of dehydration tolerance by bryophytes is of fundamental importance as they lack water-conducting tissues and are generally one cell layer thick. •Here, we show that dehydration induced oscillations in the steady-state transcript abundances of two group 3 late embryogenesis abundant (LEA) protein genes in P. patens protonemata, and that the amplitudes of these oscillations are reflective of the severity of dehydration stress. •Dehydration stress also induced elevations in the concentrations of abscisic acid (ABA), and ABA alone can also induce dosage-dependent oscillatory increases in the steady-state abundance of LEA protein transcripts. Additionally, removal of ABA resulted in rapid attenuation of these oscillatory increases. •Our data demonstrate that dehydration stress-regulated expression of LEA protein genes is temporally dynamic and highlight the importance of oscillations as a robust mechanism for optimal responses. Our results suggest that dehydration stress-induced oscillations in the steady-state abundance of LEA protein transcripts may constitute an important cellular strategy for adaptation to life in a constantly changing environment.
Kevin R. Evans - One of the best experts on this subject based on the ideXlab platform.
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Evidence of major Middle Cambrian deformation in the Ross orogen, Antarctica
Geology, 1992Co-Authors: A. J. Rowell, Margaret N. Rees, Kevin R. EvansAbstract:Long-lived polyphase tectonism in the Cambrian history of the Ross orogen is demonstrated by recent stratigraphic studies in both the central and Weddell Sea segments of the Transantarctic Mountains. We postulate that strong early Middle Cambrian deformation preceded a more widely recognized Late Cambrian-Early Ordovician Period of contraction and magmatism. These Middle Cambrian movements were locally the principal phase of orogenic deformation. They profoundly altered sedimentation patterns along the Antarctic margin, so that in the Weddell Sea region, when carbonate platform sedimentation resumed, the platform margin was reestablished far oceanward of its Early Cambrian location. Intra-Cambrian tectonism along the paleo-Pacific margin of Gondwana was not confined to its Antarctic segment; comparable activity recently has been described from Australia and is known from South America. These movements may be related to amalgamation of East and West Gondwana.
Frances Downey - One of the best experts on this subject based on the ideXlab platform.
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Abiotic stress-induced oscillations in steady-state transcript levels of Group 3 LEA protein genes in the moss, Physcomitrella patens.
Plant signaling & behavior, 2012Co-Authors: Suhas Shinde, Rupali Shinde, Frances DowneyAbstract:The moss, Physcomitrella patens is a non-seed land plant belonging to early diverging lineages of land plants following colonization of land in the Ordovician Period in Earth’s history. Evidence suggests that mosses can be highly tolerant of abiotic stress. We showed previously that dehydration stress and abscisic acid treatments induced oscillations in steady-state levels of LEA (Late Embryogenesis Abundant) protein transcripts, and that removal of ABA resulted in rapid attenuation of oscillatory increases in transcript levels. Here, we show that other abiotic stresses like salt and osmotic stresses also induced oscillations in steady-state transcript levels and that the amplitudes of the oscillatory increases in steady-state transcript levels are reflective of the severity of the abiotic stress treatment. Together, our results suggest that oscillatory increases in transcript levels in response to abiotic stresses may be a general phenomenon in P. patens and that temporally dynamic increases in steady-state transcript levels may be important for adaptation to life in constantly fluctuating environmental conditions.
Felix M Gradstein - One of the best experts on this subject based on the ideXlab platform.
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The Concise Geologic Time Scale
2008Co-Authors: Felix M GradsteinAbstract:Introduction Planetary time scale Precambrian Cambrian Period Ordovician Period Silurian Period Devonian Period Carboniferous Period Permian Period Triassic Period Jurassic Period Cretaceous Period Paleogene Period Neogene Period Quaternary Period Appendix 1 Appendix 2 Index
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The Concise Geologic Time Scale
2008Co-Authors: Felix M GradsteinAbstract:Introduction Planetary time scale Precambrian Period Cambrian Period Ordovician Period Silurian Period Devonian Period Carboniferous Period Permian Period Triassic Period Jurassic Period Cretaceous Period Paleogene Period Neogene Period Quaternary Period Appendix. Standard colors of the international divisions of geologic time References Index.
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On the Ordovician Period and Quaternary Sub-Era
GeoArabia, 2007Co-Authors: Felix M Gradstein, Stan FinneyAbstract:Until recently, there was no global standard set of stratigraphic subdivisions for the Ordovician System/ Period. British series/epochs have often been used as de facto nomenclature on stratigraphic correlation charts and geologic time scales. However, these regional subdivisions are not widely adopted outside of the British Isles and related paleobiogeographic regions (e.g. northwestern Gondwana) because the high degree of biogeographic provincialism and paleoecologic differentiation of Ordovician faunas prevent the British series from being correlated with precision and high resolution.
Julie Trotter - One of the best experts on this subject based on the ideXlab platform.
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did cooling oceans trigger Ordovician biodiversification evidence from conodont thermometry
Science, 2008Co-Authors: Ian S Williams, Christopher R. Barnes, Julie Trotter, Christophe Lecuyer, Robert S NicollAbstract:The Ordovician Period, long considered a supergreenhouse state, saw one of the greatest radiations of life in Earth's history. Previous temperature estimates of up to approximately 70 degrees C have spawned controversial speculation that the oxygen isotopic composition of seawater must have evolved over geological time. We present a very different global climate record determined by ion microprobe oxygen isotope analyses of Early Ordovician-Silurian conodonts. This record shows a steady cooling trend through the Early Ordovician reaching modern equatorial temperatures that were sustained throughout the Middle and Late Ordovician. This favorable climate regime implies not only that the oxygen isotopic composition of Ordovician seawater was similar to that of today, but also that climate played an overarching role in promoting the unprecedented increases in biodiversity that characterized this Period.
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did cooling oceans trigger Ordovician biodiversification evidence from conodont thermometry
Science, 2008Co-Authors: Ian S Williams, Christopher R. Barnes, Julie Trotter, Christophe Lecuyer, Robert S NicollAbstract:The Ordovician Period, long considered a supergreenhouse state, saw one of the greatest radiations of life in Earth9s history. Previous temperature estimates of up to ∼70°C have spawned controversial speculation that the oxygen isotopic composition of seawater must have evolved over geological time. We present a very different global climate record determined by ion microprobe oxygen isotope analyses of Early Ordovician–Silurian conodonts. This record shows a steady cooling trend through the Early Ordovician reaching modern equatorial temperatures that were sustained throughout the Middle and Late Ordovician. This favorable climate regime implies not only that the oxygen isotopic composition of Ordovician seawater was similar to that of today, but also that climate played an overarching role in promoting the unprecedented increases in biodiversity that characterized this Period.