Comparative Proteomics Analyses of Kobresia pygmaea Adaptation to Environment along an Elevational Gradient on the Central Tibetan Plateau

Variations in elevation limit the growth and distribution of alpine plants because multiple environmental stresses impact plant growth, including sharp temperature shifts, strong ultraviolet radiation exposure, low oxygen content, etc. Alpine plants have developed special strategies to help survive the harsh environments of high mountains, but the internal mechanisms remain undefined. Kobresia pygmaea, the dominant species of alpine meadows, is widely distributed in the Southeastern Tibet Plateau, Tibet Autonomous Region, China. In this study, we mainly used comparative proteomics analyses to investigate the dynamic protein patterns for K. pygmaea located at four different elevations (4600, 4800, 4950 and 5100 m). A total of 58 differentially expressed proteins were successfully detected and functionally characterized. The proteins were divided into various functional categories, including material and energy metabolism, protein synthesis and degradation, redox process, defense response, photosynthesis, and protein kinase. Our study confirmed that increasing levels of antioxidant and heat shock proteins and the accumulation of primary metabolites, such as proline and abscisic acid, conferred K. pygmaea with tolerance to the alpine environment. In addition, the various methods K. pygmaea used to regulate material and energy metabolism played important roles in the development of tolerance to environmental stress. Our results also showed that the way in which K. pygmaea mediated stomatal characteristics and photosynthetic pigments constitutes an enhanced adaptation to alpine environmental stress. According to these findings, we concluded that K. pygmaea adapted to the high-elevation environment on the Tibetan Plateau by aggressively accumulating abiotic stress-related metabolites and proteins and by the various life events mediated by proteins. Based on the species'lexible physiological and biochemical processes, we surmised that environment change has only a slight impact on K. pygmaea except for possible impacts to populations on vulnerable edges of the species' range.

[1]  V. Kuznetsov,et al.  Stress responses of tobacco cells to high temperature and salinity. Proline accumulation and phosphorylation of polypeptides , 1997 .

[2]  C. Vílchez,et al.  UV-A mediated induction of carotenoid accumulation in Dunaliella bardawil with retention of cell viability , 2005, Applied Microbiology and Biotechnology.

[3]  C. Körner,et al.  Altitudinal variation in stomatal conductance, nitrogen content and leaf anatomy in different plant life forms in New Zealand , 1986, Oecologia.

[4]  K. Akashi,et al.  Wild plant resources for studying molecular mechanisms of drought/strong light stress tolerance , 2008 .

[5]  L. Fraser,et al.  Adaptive phenotypic plasticity of Pseudoroegneria spicata: response of stomatal density, leaf area and biomass to changes in water supply and increased temperature. , 2009, Annals of botany.

[6]  H. Feng,et al.  Variations of stomatal density and carbon isotope values of Picea crassifolia at different altitudes in the Qilian Mountains , 2003, Trees.

[7]  K. Asada,et al.  Hydrogen Peroxide is Scavenged by Ascorbate-specific Peroxidase in Spinach Chloroplasts , 1981 .

[8]  J. Gale.  Availability of carbon dioxide for photosynthesis at high altitudes : theoretical considerations , 1972 .

[9]  M. Foolad,et al.  Roles of glycine betaine and proline in improving plant abiotic stress resistance , 2007 .

[10]  M. Qi,et al.  Photosynthesis, photoinhibition, and antioxidant system in tomato leaves stressed by low night temperature and their subsequent recovery. , 2012, Plant science : an international journal of experimental plant biology.

[11]  Jan Hanspach,et al.  Plant communities of central Tibetan pastures in the Alpine Steppe / Kobresia pygmaea ecotone , 2011 .

[12]  Jianhua Zhang,et al.  Nitric oxide mediates brassinosteroid-induced ABA biosynthesis involved in oxidative stress tolerance in maize leaves. , 2011, Plant & cell physiology.

[13]  R. Mittler.  Oxidative stress, antioxidants and stress tolerance. , 2002, Trends in plant science.

[14]  M. Zivy,et al.  Technical improvements in two‐dimensional electrophoresis increase the level of genetic variation detected in wheat‐seedling proteins , 1986 .

[15]  G. Farquhar,et al.  The effect of exogenous abscisic acid on stomatal development, stomatal mechanics, and leaf gas exchange in Tradescantia virginiana. , 2001, Plant physiology.

[16]  Harold A. Mooney,et al.  THE ECOLOGY OF ARCTIC AND ALPINE PLANTS , 1968 .

[17]  K. R. Reddy,et al.  Interactions of CO2 enrichment and temperature on cotton growth and leaf characteristics , 1998 .

[18]  Michael Gottfried,et al.  Prediction of Vegetation Patterns at the Limits of Plant Life: A New View of the Alpine-Nival Ecotone , 1998 .

[19]  M. Grosjean,et al.  Climate Variability and Change in High Elevation Regions: Past, Present and Future , 2003 .

[20]  I. D. Teare,et al.  Rapid determination of free proline for water-stress studies , 1973, Plant and Soil.

[21]  C. Todd,et al.  Comparative proteome analyses reveal that nitric oxide is an important signal molecule in the response of rice to aluminum toxicity. , 2013, Journal of proteome research.

[22]  D. Beerling,et al.  Stomatal Density Responses of Egyptian Olea europaea L. Leaves to CO2 Change Since 1327 BC , 1993 .

[23]  K. Kosová,et al.  Expression of dehydrins in wheat and barley under different temperatures. , 2011, Plant science : an international journal of experimental plant biology.

[24]  Xinquan Zhao,et al.  Status and Dynamics of the Kobresia pygmaea Ecosystem on the Tibetan Plateau , 2008, Ambio.

[25]  W. Deng,et al.  Changes in photosynthesis, chlorophyll fluorescence, and antioxidant enzymes of mulberry (Morus ssp.) in response to salinity and high-temperature stress , 2013, Biologia.

[26]  K. Shinozaki,et al.  Crosstalk between abiotic and biotic stress responses: a current view from the points of convergence in the stress signaling networks. , 2006, Current opinion in plant biology.

[27]  Kazuo Shinozaki,et al.  Mitogen-activated protein kinase cascades in plants: a new nomenclature. , 2002, Trends in plant science.

[28]  H. Hirt,et al.  Reactive oxygen species: metabolism, oxidative stress, and signal transduction. , 2004, Annual review of plant biology.

[29]  B. Glick,et al.  Strategies to ameliorate abiotic stress-induced plant senescence , 2013, Plant Molecular Biology.

[30]  Josep Peñuelas,et al.  Changes in N and S Leaf Content, Stomatal Density and Specific Leaf Area of 14 Plant Species during the Last Three Centuries of CO2 Increase , 1990 .

[31]  F. Woodward,et al.  Photosynthetic pathway and ecological adaptation explain stomatal trait diversity amongst grasses. , 2012, The New phytologist.

[32]  Bao Lou,et al.  Effect of high water temperature on growth, survival and antioxidant enzyme activities in the Japanese flounder Paralichthys olivaceus , 2011 .

[33]  M. Jiang,et al.  Effect of abscisic acid on active oxygen species, antioxidative defence system and oxidative damage in leaves of maize seedlings. , 2001, Plant & cell physiology.

[34]  F. Miglietta,et al.  Elevated CO2 concentrations and stomatal density: observations from 17 plant species growing in a CO2 spring in central Italy , 1998 .

[35]  Lee,et al.  Chilling stress-induced changes of antioxidant enzymes in the leaves of cucumber: in gel enzyme activity assays. , 2000, Plant science : an international journal of experimental plant biology.

[36]  U. K. Laemmli,et al.  A factor preventing the major head protein of bacteriophage T4 from random aggregation. , 1970, Journal of molecular biology.

[37]  K. Yamagishi,et al.  Identification of cytoplasmic and nuclear low-molecular-weight heat-shock proteins in tomato fruit. , 1993, Plant & cell physiology.

[38]  H. Lichtenthaler.  CHLOROPHYLL AND CAROTENOIDS: PIGMENTS OF PHOTOSYNTHETIC BIOMEMBRANES , 1987 .

[39]  K. Georgieva,et al.  Desiccation of the resurrection plant Haberlea rhodopensis at high temperature , 2011, Photosynthesis Research.

[40]  Dominique C Bergmann,et al.  Stomatal Development and Pattern Controlled by a MAPKK Kinase , 2004, Science.

[41]  Jian-Kang Zhu,et al.  Cell Signaling during Cold, Drought, and Salt Stress Article, publication date, and citation information can be found at www.plantcell.org/cgi/doi/10.1105/tpc.000596. , 2002, The Plant Cell Online.

[42]  John C. Walker,et al.  Stomatal Development and Patterning Are Regulated by Environmentally Responsive Mitogen-Activated Protein Kinases in Arabidopsis[W] , 2007, The Plant Cell Online.

[43]  H. Kamada,et al.  Patterns of expression of the genes for glutamine synthetase isoforms during somatic and zygotic embryogenesis in carrot. , 1998, Plant & cell physiology.

[44]  P. Ahmad,et al.  Deciphering the protective role of nitric oxide against salt stress at the physiological and proteomic levels in maize. , 2011, Journal of proteome research.

[45]  J. Schroeder,et al.  Guard cell ABA and CO2 signaling network updates and Ca2+ sensor priming hypothesis. , 2006, Current opinion in plant biology.

[46]  Yong Wang,et al.  Comparative physiological and proteomic responses to drought stress in two poplar species originating from different altitudes. , 2010, Physiologia plantarum.

[47]  C. Todd,et al.  Comparative proteomic analysis of the thermotolerant plant Portulaca oleracea acclimation to combined high temperature and humidity stress. , 2012, Journal of proteome research.

[48]  D. Renault,et al.  Heat shock protein responses to salinity, food deprivation, and temperature in the invasive ground beetle Merizodus soledadinus at the Kerguelen Islands , 2012, Polar Biology.

[49]  C. Yin,et al.  Physiological responses to drought and shade in two contrasting Picea asperata populations , 2005 .

[50]  J. Marshall,et al.  Altitude trends in conifer leaf morphology and stable carbon isotope composition , 2000, Oecologia.

[51]  K. Gaston,et al.  Contrasting response of native and alien plant species richness to environmental energy and human impact along alpine elevation gradients. , 2009 .