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Pea is a conventional grain-feed-grass crop in Tibet and the only high-protein legume in the region; therefore, it plays an important role in Tibetan food and grass security. Zinc finger-homeodomain (ZF-HD) belongs to a family of homozygous heterotypic cassette genes, which play an important role in plant growth, development, and response to adversity stress. Using a bioinformatics approach, 18 PsZF-HD family members were identified. These genes were distributed across seven chromosomes and two scaffold fragments, and evolutionary analysis classified them into two subgroups, MIF and ZHD. The MIF subgroup was subdivided into three subclasses (PsMIFI-III), and the ZHD subgroup was subdivided into five subclasses (ZHDI-V). The PsZF-HD members were named PsMIF1-PsMIF4 and PsZHD1-PsZHD14. Twelve conserved motifs and four conserved domains were identified from PsZF-HD family, of which MIF subgroup only contained one domain, while ZHD subgroup contained two types of domains. In addition, there were significant differences in the three-dimensional structures of the protein members of the two subgroups. Most PsZF-HD genes had no introns (13/18), and only five genes had one intron. Forty-five cis-acting elements were predicted and screened, involving four categories: light response, stress, hormone, and growth and development. Transcriptome analysis of different tissues during pea growth and development showed that PsZHD11, 8, 13, 14 and MIF4 were not expressed or were individually expressed in low amounts in the tissues, while the other 13 PsZF-HDs genes were differentially expressed and showed tissue preference, as seen in aboveground reproductive organs, where PsZHD6, 2, 10 and MIF1 (except immature seeds) were highly expressed. In the aerial vegetative organs, PsZHD6, 1, and 10 were significantly overexpressed, while in the underground root system, PsMIF3 was specifically overexpressed. The leaf transcriptome under a low-nitrogen environment showed that the expression levels of 17 PsZF-HDs members were upregulated in shoot organs. The leaf transcriptome analysis under a lowtemperature environment showed stress-induced upregulation of PsZHD10 and one genes and down-regulation of PsZHD6 gene. These results laid the foundation for deeper exploration of the functions of the PsZF-HD genes and also improved the reference for molecular breeding for stress resistance in peas. [ABSTRACT FROM AUTHOR]

This study uses geochemical mohometers to investigate the paleo‐crustal thickness and elevation of western Tibet through the Cretaceous to Eocene. The northern Lhasa Block and southern Qiangtang Block (QB) had a similar paleo‐crustal thickness of ∼55 km during the Late Cretaceous, but the latter had reached its present‐day thickness (∼70 km) and elevation (∼5.5 km) by the mid‐Eocene, which was not caused by underthrusting of Indian crust according to isotopic evidence. Our study demonstrates the western and central QB shared a similar early Paleogene tectonomagmatic evolution with the formation of a continues proto‐plateau in central Tibet, resulting from crustal shortening and subsequent lithospheric foundering. This in turn implies underthrusting of the Indian lithosphere beneath the western QB after Eocene, given the present‐day lithospheric difference between the western and central QB. Our reconstruction of paleo‐crustal thickness and elevation, however, suggests the Indian underthrusting caused minimal further crustal thickening and uplift. Plain Language Summary: The Tibetan Plateau is a key locality to study large‐scale continental tectonics because of the well‐preserved Cenozoic geological records along with the validity of geophysical data. The western part of the Tibetan Plateau is not a simple extension of the central‐eastern part as demonstrated by numerous geophysical investigations on the lithospheric structure. The western Qiangtang Block (QB) in central Tibet is generally thought to be raised by the Miocene underthrusting of the Indian lithosphere, yet no palaeoaltimetry data are available to test this hypothesis. This provides the first quantitative constraint on the uplift history of the western QB. We use recently calibrated igneous geochemical proxies of continental thickness to investigate the paleo‐crustal thickness and elevation of western Tibet through the Early Cretaceous to Eocene. Our data demonstrate that the western Tibetan crust had reached its present‐day thickness (∼70 km) and elevation (∼5.5 km) by the Mid‐Eocene, as a result of crustal shortening and subsequent lithospheric foundering. Based on a synthesis of independent geological and seismic data, we contend that the post‐Eocene underthrusting of the Indian lithosphere beneath the western QB has caused minimal further crustal thickening and uplift. Key Points: First quantitative constraint on the uplift history of the western Qiangtang Block (QB) in central TibetThe western QB has reached its present‐day thickness and elevation by EoceneUnderthrusting of the Indian lithosphere caused minimal further thickening and uplift of the western Qiangtang crust [ABSTRACT FROM AUTHOR]

Yak is an important livestock animal for the people indigenous to the harsh, oxygen‐limited Qinghai‐Tibetan Plateau and Hindu Kush ranges of the Himalayas. The yak genome was sequenced in 2012, but its assembly was fragmented because of the inherent limitations of the Illumina sequencing technology used to analyse it. An accurate and complete reference genome is essential for the study of genetic variations in this species. Long‐read sequences are more complete than their short‐read counterparts and have been successfully applied towards high‐quality genome assembly for various species. In this study, we present a high‐quality chromosome‐scale yak genome assembly (BosGru_PB_v1.0) constructed with long‐read sequencing and chromatin interaction technologies. Compared to an existing yak genome assembly (BosGru_v2.0), BosGru_PB_v1.0 shows substantially improved chromosome sequence continuity, reduced repetitive structure ambiguity, and gene model completeness. To characterize genetic variation in yak, we generated de novo genome assemblies based on Illumina short reads for seven recognized domestic yak breeds in Tibet and Sichuan and one wild yak from Hoh Xil. We compared these eight assemblies to the BosGru_PB_v1.0 genome, obtained a comprehensive map of yak genetic diversity at the whole‐genome level, and identified several protein‐coding genes absent from the BosGru_PB_v1.0 assembly. Despite the genetic bottleneck experienced by wild yak, their diversity was nonetheless higher than that of domestic yak. Here, we identified breed‐specific sequences and genes by whole‐genome alignment, which may facilitate yak breed identification. [ABSTRACT FROM AUTHOR]

Background: On the Qinghai–Tibet Plateau, known as the roof ridge of the world, the yak is a precious cattle species that has been indispensable to the human beings living in this high-altitude area. However, the origin of domestication, dispersal route, and the divergence of domestic yaks from different areas are poorly understood. Results: Here, we resequenced the genome of 91 domestic yak individuals from 31 populations and 1 wild yaks throughout China. Using a population genomics approach, we observed considerable genetic variation. Phylogenetic analysis suggested that the earliest domestications of yak occurred in the south-eastern QTP, followed by dispersal to the west QTP and northeast to SiChuang, Gansu, and Qinghai by two routes. Interestingly, we also found potential associations between the distribution of some breeds and historical trade routes such as the Silk Road and Tang-Tibet Ancient Road. Selective analysis identified 11 genes showing differentiation between domesticated and wild yaks and the potentially positively selected genes in each group were identified and compared among domesticated groups. We also detected an unbalanced pattern of introgression among domestic yak, wild yak, and Tibetan cattle. Conclusions: Our research revealed population genetic evidence for three groups of domestic yaks. In addition to providing genomic evidence for the domestication history of yaks, we identified potential selected genes and introgression, which provide a theoretical basis and resources for the selective breeding of superior characters and high-quality yak. [ABSTRACT FROM AUTHOR]

The post-collisional evolution of the Tibetan lithosphere is of paramount significance to our understanding of collisional orogeny. It is generally postulated that the Lhasa lithospheric mantle was horizontally shortened and thickened coherently with the overlying crust to form a physical barrier, preventing Indian subduction beneath Tibet until the thickened mantle root was foundered during the Miocene. This study first identifies post-collisional oceanic-island basalt (OIB)-type magmatism in the Lhasa Block (LB), as attested by zircon U-Pb age (ca. 58 Ma) and geochemistry--positive Nb-Ta anomalies, high La/Yb, and depleted bulkrock Sr-Nd and zircon Hf isotopes, of diabase in the northern (inboard relative to Indus Suture) part of this block. Coupled with extensive early Paleogene arc-type magmatism in the southern-central LB and thermodynamic modeling, we suggest that these diabases were formed by partially molten upwelling asthenosphere near the base of continental crust, where much of the underlying lithospheric mantle had been removed due to Neo-Tethyan slab rollback and lithospheric delamination. Compared to OIB-type magmatism worldwide, the diabases investigated here were emplaced peculiarly in a region where the continental crust was under horizontal compression and shortening by coeval thrusting. Our study thus implies a decoupled deformation between the crust and mantle of the LB during the early Indian-Asian collision. [ABSTRACT FROM AUTHOR]

This study presents new major and trace element, plus Sr–Nd and zircon U–Pb isotope data for the Zhongcang granitic plutons, which are located to the south of the Yongzhu–Asuo ophiolite belt within the northwestern part of the central Lhasa subterrane, Tibetan Plateau. These data provide new insights into the Late Cretaceous tectonic evolution of southern Tibet. The Zhongcang plutons are dominated by granodiorites and granites that yield zircon U–Pb emplacement ages of 94–88 Ma. They can be further divided into metaluminous and peraluminous subtypes. The metaluminous rocks have adakite-like geochemical signatures, including high SiO 2 , Al 2 O 3 , and Sr concentrations, and low Yb and Y concentrations, and high Sr/Y and (La/Yb) N ratios. These rocks also have negative εNd (t) values (− 3.17 to − 0.17), variable initial 87 Sr/ 86 Sr (i) ratios (0.705927–0.707668), and high K 2 O and Th concentrations, suggesting that they were not derived from the partial melting of subducted oceanic crust in an arc setting. The Zhongcang adakitic rocks have higher MgO and Cr concentrations and Mg# values than do contemporaneous intrusive rocks derived from a region of thickened lower crust within the central Lhasa subterrane. These data suggest that the Zhongcang adakitic rocks were generated by the partial melting of a delaminated thickened lower crust within a Late Cretaceous continental setting. In comparison with the Zhongcang adakitic rocks, the peraluminous rocks have significant negative Eu and Sr anomalies and lower εNd (t) values (− 4.06 to − 6.64). This, combined with their high Mg# values, and Cr concentrations, suggests that the peraluminous units formed from primitive magmas similar to those that formed the Zhongcang adakitic rocks, but modified by contamination with ancient crustal material and by fractional crystallization of plagioclase and apatite during uprising and/or emplacement. The Zhongcang high-Mg# granitoids provide robust evidence for Late Cretaceous crustal thickening prior to India–Asia collision. [ABSTRACT FROM AUTHOR]