scholarly journals Genomic analyses reveal evolutionary and geologic context for the plateau fungus Ophiocordyceps sinensis

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Jie Liu ◽  
Linong Guo ◽  
Zongwei Li ◽  
Zhe Zhou ◽  
Zhen Li ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Single Molecule ◽  
Enrichment Analysis ◽  
Extreme Environment ◽  
High Elevation ◽  
Metal Resistance ◽  
Repeat Sequence ◽  
The Tibetan Plateau ◽  
Ltr Retrotransposon ◽  
Ophiocordyceps Sinensis

Abstract Background Ophiocordyceps sinensis, which is only naturally found in the high-elevation extreme environment of the Tibetan Plateau, has been used in traditional Chinese medicine. Information concerning the evolutionary and geologic context of O. sinensis remains limited, however. Methods We constructed the high-quality genome of O. sinensis and provided insight into the evolution and ecology of O. sinensis using comparative genomics. Results We mapped the whole genome of the anamorph/asexual form Hirsutella of O. sinensis using Illumina and PacBio sequencing technologies and obtained a well assembled genome of 119.2 Mbp size. Long-read Single Molecule Real Time (SMRT) sequencing technology generated an assembly with more accurate representation of repeat sequence abundances and placement. Evolutionary analyses indicated that O. sinensis diverged from other fungi 65.9 Mya in the Upper Cretaceous, during the uplift of the Tibetan Plateau. Gene family expansions and contractions in addition to genome inflation via long terminal repeat (LTR) retrotransposon insertions were implicated as an important driver of O. sinensis divergence. The insertion rate of LTR sequences into the O. sinensis genome peaked ~ 30–40 Mya, when the Tibetan Plateau rose rapidly. Gene Ontology (GO) enrichment analysis suggested that O. sinensis contained more genes related to ice binding compared to other closely related fungi, which may aid in their adaptability to the cold Tibetan Plateau. Further, heavy metal resistance genes were in low abundance in the O. sinensis genome, which may help to explain previous observations that O. sinensis tissues contain high levels of heavy metals. Conclusions Our results reveal the evolutionary, geological, and ecological context for the evolution of the O. sinensis genome and the factors that have contributed to the environmental adaptability of this valuable fungus. These findings suggest that genome inflation via LTR retrotransposon insertions in O. sinensis coincided with the uplift of the Tibetan Plateau. LTRs and the specific genetic mechanisms of O. sinensis contributed to its adaptation to the environment on the plateau.

scholarly journals Linking deeply-sourced volatile emissions to plateau growth dynamics in southeastern Tibetan Plateau

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Maoliang Zhang ◽  
Zhengfu Guo ◽  
Sheng Xu ◽  
Peter H. Barry ◽  
Yuji Sano ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Growth Dynamics ◽  
High Elevation ◽  
Fault System ◽  
The Tibetan Plateau ◽  
Southeastern Tibetan Plateau ◽  
Surface Uplift ◽  
Multi Stage ◽  
Geodynamic Processes ◽  
Underlying Mechanisms

AbstractThe episodic growth of high-elevation orogenic plateaux is controlled by a series of geodynamic processes. However, determining the underlying mechanisms that drive plateau growth dynamics over geological history and constraining the depths at which growth originates, remains challenging. Here we present He-CO2-N2 systematics of hydrothermal fluids that reveal the existence of a lithospheric-scale fault system in the southeastern Tibetan Plateau, whereby multi-stage plateau growth occurred in the geological past and continues to the present. He isotopes provide unambiguous evidence for the involvement of mantle-scale dynamics in lateral expansion and localized surface uplift of the Tibetan Plateau. The excellent correlation between 3He/4He values and strain rates, along the strike of Indian indentation into Asia, suggests non-uniform distribution of stresses between the plateau boundary and interior, which modulate southeastward growth of the Tibetan Plateau within the context of India-Asia convergence. Our results demonstrate that deeply-sourced volatile geochemistry can be used to constrain deep dynamic processes involved in orogenic plateau growth.

Roof of the World: Tibet, Pamirs

2013 ◽  
Author(s):  
Mike Searle
Keyword(s):  
Tibetan Plateau ◽  
High Elevation ◽  
Tien Shan ◽  
Palm Tree ◽  
The Tibetan Plateau ◽  
Wet Season ◽  
North West ◽  
Mountain Ranges ◽  
The North ◽  
The World

The Tibetan Plateau is by far the largest region of high elevation, averaging just above 5,000 metres above sea level, and the thickest crust, between 70 and 90 kilometres thick, anywhere in the world. This huge plateau region is very flat—lying in the internally drained parts of the Chang Tang in north and central Tibet, but in parts of the externally drained eastern Tibet, three or four mountain ranges larger and higher than the Alps rise above the frozen plateau. Some of the world’s largest and longest mountain ranges border the plateau, the ‘flaming mountains’ of the Tien Shan along the north-west, the Kun Lun along the north, the Longmen Shan in the east, and of course the mighty Himalaya forming the southern border of the plateau. The great trans-Himalayan mountain ranges of the Pamir and Karakoram are geologically part of the Asian plate and western Tibet but, as we have noted before, unlike Tibet, these ranges have incredibly high relief with 7- and 8-kilometre-high mountains and deeply eroded rivers and glacial valleys. The western part of the Tibetan Plateau is the highest, driest, and wildest area of Tibet. Here there is almost no rainfall and rivers that carry run-off from the bordering mountain ranges simply evaporate into saltpans or disappear underground. Rivers draining the Kun Lun flow north into the Takla Makan Desert, forming seasonal marshlands in the wet season and a dusty desert when the rivers run dry. The discovery of fossil tropical leaves, palm tree trunks, and even bones from miniature Miocene horses suggest that the climate may have been wetter in the past, but this is also dependent on the rise of the plateau. Exactly when Tibet rose to its present elevation is a matter of great debate. Nowadays the Indian Ocean monsoon winds sweep moisture-laden air over the Indian sub-continent during the summer months (late June–September). All the moisture is dumped as the summer monsoon, the torrential rains that sweep across India from south-east to north-west.

scholarly journals Three new needle-shaped Fragilaria species from Central America and the Tibetan Plateau

Phytotaxa ◽  
2021 ◽  
Vol 479 (1) ◽  
pp. 1-22
Author(s):  
KIM J. KRAHN ◽  
ANJA SCHWARZ ◽  
CARLOS E. WETZEL ◽  
SERGIO COHUO-DURÁN ◽  
GERHARD DAUT ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Specific Conductivity ◽  
Central Area ◽  
High Elevation ◽  
Width Ratio ◽  
Similar Species ◽  
The Tibetan Plateau ◽  
Alkaline Ph ◽  
Apical Pore ◽  
Lake Nam Co

Three new needle-shaped Fragilaria species from freshwater lake Apastepeque in El Salvador (Fragilaria salvadoriana sp. nov., F. maarensis sp. nov.) and subsaline lake Nam Co on the Tibetan Plateau (F. huebeneri sp. nov.) are described and compared based on light and scanning electron microscopy observations and morphometric analyses. Fragilaria salvadoriana sp. nov. is characterized by narrowly linear-lanceolate, sometimes centrally constricted valves, subcapitate to rarely capitate apices, and a distinct, dented appearing central area. Striae are composed of 2−5 occluded areolae. It can be differentiated from similar needle-shaped species by the valve outline, relatively low striae density, and shark fin-shaped spines. Characteristic of F. maarensis sp. nov. are a very narrowly lanceolate valve outline and subcapitate apices. The apical pore field is composed of 2–3 rows of poroids and acute, irregularly oriented spines are present at the junction between valve face and mantle. This taxon is clearly different from other Fragilaria species, displaying a high length-to-width ratio and a low number of areolae per stria. The Tibetan species, F. huebeneri sp. nov., forms long ribbon-like colonies linked together by spatula-shaped spines. Valves have subcapitate apices, a spindle- to needle-shaped outline and an indistinct central area. Striae are alternate and composed of 3–5 areolae per stria. Teratological forms of F. huebeneri sp. nov. were commonly observed in the sediment trap samples. Fragilaria salvadoriana sp. nov. and F. maarensis sp. nov. were found in a warm, tropical crater lake characterized by low conductivity and dissolved oxygen content, medium alkaline pH, and magnesium-calcium-bicarbonate-rich waters. Fragilaria huebeneri sp. nov. was frequent in a large, high elevation lake with increased specific conductivity, alkaline pH and sodium-bicarbonate-rich waters. The new species are compared to morphologically similar species from the genus Fragilaria Lyngbye and ecological preferences are discussed.

scholarly journals Towards ice thickness inversion: an evaluation of global DEMs by ICESat-2 in the glacierized Tibetan Plateau

2021 ◽  
Author(s):  
Wenfeng Chen ◽  
Tandong Yao ◽  
Guoqing Zhang ◽  
Fei Li ◽  
Guoxiong Zheng ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Mean Squared Error ◽  
High Elevation ◽  
Global Scale ◽  
Primary Data ◽  
Ice Thickness ◽  
The Tibetan Plateau ◽  
Glacier Surface ◽  
The North ◽  
Elevation Model

Abstract. Accurate estimates of regional ice thickness, which are generally produced by ice-thickness inversion models, are crucial for assessments of available freshwater resources and sea level rise. Digital elevation model (DEM) derived surface topography of glaciers is a primary data source for such models. However, the scarce in-situ measurements of glacier surface elevation limit the evaluation of DEM uncertainty, and hence its influence on ice-thickness modelling over the glacierized area of the Tibetan Plateau (TP). Here, we examine the performance over the glacierized TP of six widely used and mainly global-scale DEMs: AW3D30 (30 m), SRTM-GL1 (30 m), NASADEM (30 m), TanDEM-X (90 m), SRTM v4.1 (90 m) and MERIT (90 m) by using ICESat-2 laser altimetry data while considering the effects of glacier dynamics, terrain, and DEM misregistration. The results reveal NASADEM as the best performer, with a small mean error (ME) of −1.0 and a root mean squared error (RMSE) of 12.6 m. A systematic vertical offset existed in AW3D30 (−35.3 ME and 34.9 m RMSE), although it had a similar relative accuracy to NASADEM (~ 13 m STD). TanDEM-X also performs well (−0.1 ME and 15.1 m RMSE), but suffers from serious errors and outliers on steep slopes. SRTM-based DEMs (SRTM-GL1, SRTM v4.1, and MERIT) (all ~ 36 m RMSE) had an inferior performance to NASADEM. However, their errors were reduced in the ablation zone when glacier variations were excluded. Errors in the six DEMs increased from the south-facing to the north-facing aspect and become larger with increasing slope. Misregistration of DEMs relative to ICESat-2 footprint in most glacier areas is small (less than one pixel). An intercomparison of four ice-thickness models: GlabTop2, Open Global Glacier Model (OGGM), Huss-Farinotti (HF), Ice Thickness Inversion Based on Velocity (ITIBOV), show that GlabTop2 is sensitive to the accuracy of both elevation and slope, while OGGM and HF are less sensitive to DEM quality, and ITIBOV is the most sensitive to slope accuracy. Considering the inconsistency of DEMs acquisition dates, NASADEM would be a best choice for ice-thickness estimates over the TP, followed by AW3D30, and TanDEM-X (if steep and high elevation terrain can be avoided). Our assessment figures out the performances of mainly global DEMs over the glacierized TP. This study not only avails the glacier thickness estimation with ice thickness inversion models, but also offered references for other cryosphere studies using DEM.

scholarly journals Growth of a high-elevation large inland lake, associated with climate change and permafrost degradation in Tibet

2009 ◽  
Vol 6 (4) ◽  
pp. 5445-5469 ◽  
Author(s):  
J. Liu ◽  
S. Kang ◽  
T. Gong ◽  
A. Lu
Keyword(s):  
Tibetan Plateau ◽  
High Elevation ◽  
Annual Runoff ◽  
Annual Precipitation ◽  
The Tibetan Plateau ◽  
Permafrost Degradation ◽  
Lake Area ◽  
Pan Evaporation ◽  
Inland Lake ◽  
Precipitation Increase

Abstract. This study analyzed satellite images and long term climate variables from a high-elevation meteorological station (4730 m) and streamflow records to examine hydrological response of Nam Co Lake (4718 m), the largest lake on the Tibetan Plateau, over the last 50 years. The results show the lake area extended by 51.8 km2 (2.7% of the total area) when compared with the area in 1976. This change is associated with an annual precipitation increase of 65 mm (18.6%), annual and winter mean temperature increases of 0.9°C and 2.1°C respectively, an annual runoff increase of 20% and an annual pan evaporation decrease of about 2%, during the past 20 years. The year of the change point in annual precipitation, air temperature, annual pan evaporation and runoff occurred in 1971, 1983, 1997 and 1997, respectively. The timing of the lake growth corresponds with the abrupt increase in annual precipitation and runoff since the mid-1990s. This study suggests a strong positive water balance in the largest inland lake on the Tibetan Plateau.

Evapotranspiration and water balance of high-elevation grassland on the Tibetan Plateau

2016 ◽  
Vol 533 ◽  
pp. 557-566 ◽  
Author(s):  
Heinz Coners ◽  
Wolfgang Babel ◽  
Sandra Willinghöfer ◽  
Tobias Biermann ◽  
Lars Köhler ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Water Balance ◽  
High Elevation ◽  
The Tibetan Plateau
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