In this paper we present new zircon U–Pb ages, Hf isotope data, and whole-rock major and trace element data for Early Mesozoic intrusive rocks in the Erguna Massif of NE China, and we use these data ...to constrain the history of southward subduction of the Mongol–Okhotsk oceanic plate, and its influence on NE China as a whole. The zircon U–Pb dating indicates that Early Mesozoic magmatic activity in the Erguna Massif can be subdivided into four stages at ~246Ma, ~225Ma, ~205Ma, and ~185Ma. The ~246Ma intrusive rocks comprise a suite of high-K calc-alkaline diorites, quartz diorites, granodiorites, monzogranites, and syenogranites, with I-type affinities. The ~225Ma intrusive rocks consist of gabbro–diorites and granitoids, and they constitute a bimodal igneous association. The ~205Ma intrusive rocks are dominated by calc-alkaline I-type granitoids that are accompanied by subordinate intermediate–mafic rocks. The ~185Ma intrusive rocks are dominated by I-type granitoids, accompanied by minor amounts of A-types. These Early Mesozoic granitoids mainly originated by partial melting of a depleted and heterogeneous lower crust, whereas the coeval mafic rocks were probably derived from partial melting of a depleted mantle modified by subduction-related fluids. The rock associations and their geochemical features indicate that the ~246Ma, ~205Ma, and ~185Ma intrusive rocks formed in an active continental margin setting related to the southward subduction of the Mongol–Okhotsk oceanic plate. The ~225Ma bimodal igneous rock association formed within an extensional environment in a pause during the subduction process of the Mongol–Okhotsk oceanic plate. Every magmatic stage has its own corresponding set of porphyry deposits in the southeast of the Mongol–Okhotsk suture belt. Taking all this into account, we conclude the following: (1) during the Early Mesozoic, the Mongol–Okhotsk oceanic plate was subducted towards the south beneath the Erguna Massif, but with a pause in subduction at ~225Ma; and (2) the southward subduction of the Mongol–Okhotsk oceanic plate not only caused the intense magmatic activity, but was also favorable to the formation of porphyry deposits.
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•Early Mesozoic magmatisms in the Erguna Massif can be subdivided into four stages.•Early Mesozoic magmatisms formed mainly in an active continental margin setting.•The Mongol–Okhotsk oceanic plate was subducted southward during Early Mesozoic.
Diosgenin is a spiroketal steroidal natural product extracted from plants and used as the single most important precursor for the world steroid hormone industry. The sporadic occurrences of diosgenin ...in distantly related plants imply possible independent biosynthetic origins. The characteristic 5,6-spiroketal moiety in diosgenin is reminiscent of the spiroketal moiety present in anthelmintic avermectins isolated from actinomycete bacteria. How plants gained the ability to biosynthesize spiroketal natural products is unknown. Here, we report the diosgenin-biosynthetic pathways in himalayan paris (Paris polyphylla), a monocot medicinal plant with hemostatic and antibacterial properties, and fenugreek (Trigonella foenum-graecum), an eudicot culinary herb plant commonly used as a galactagogue. Both plants have independently recruited pairs of cytochromes P450 that catalyze oxidative 5,6-spiroketalization of cholesterol to produce diosgenin, with evolutionary progenitors traced to conserved phytohormone metabolism. This study paves the way for engineering the production of diosgenin and derived analogs in heterologous hosts.
The re-emergence of Zika virus (ZIKV) in the Western Hemisphere has resulted in global public health crisis since 2015. ZIKV preferentially infects and targets human neural progenitor cells (hNPCs) ...and causes fetal microcephaly upon maternal infection. hNPCs not only play critical roles during fetal brain development, but also persist in adult brain throughout life. Yet the mechanism of innate antiviral immunity in hNPCs remains largely unknown. Here, we show that ZIKV infection triggers the abundant production of virus-derived small interfering RNAs in hNPCs, but not in the more differentiated progenies or somatic cells. Ablation of key RNAi machinery components significantly enhances ZIKV replication in hNPCs. Furthermore, enoxacin, a broad-spectrum antibiotic that is known as an RNAi enhancer, exerts potent anti-ZIKV activity in hNPCs and other RNAi-competent cells. Strikingly, enoxacin treatment completely prevents ZIKV infection and circumvents ZIKV-induced microcephalic phenotypes in brain organoid models that recapitulate human fetal brain development. Our findings highlight the physiological importance of RNAi-mediated antiviral immunity during the early stage of human brain development, uncovering a novel strategy to combat human congenital viral infections through enhancing RNAi.
Exosomes extracted from mesenchymal stem cells (MSCs) was reported to reduce myocardial ischemia/reperfusion damage. Besides, stromal‐derived factor 1 (SDF1a) functions as cardiac repair after ...myocardial infarction (MI). Therefore, the present study aims to identify whether exosomes (Exo) released from SDF1‐overexpressing MSCs display a beneficial effect on ischemic myocardial infarction. Initially, a gain‐of‐function study was performed to investigate the function of SDF1 in ischemic myocardial cells and cardiac endothelial cells. Coculture experiments were performed to measure potential exosomic transfer of SDF1 from MSCs to ischemic myocardial cells and cardiac endothelial cells. During the coculture experiments, exosome secretion was disrupted by neutral sphingomyelinase inhibitor GW4869 and upregulated exosomal SDF1 using SDF1 plasmid. Effects of Exo‐SDF1 on cardiac function in MI mice were investigated in vivo. MSCs suppressed myocardial cell apoptosis and promoted microvascular regeneration of endothelial cells through secretion of exosomes. The addition of GW4869 led to increased apoptotic capacity of myocardial cells, decreased microvascular formation ability of endothelial cells, enhanced autophagy ability, and elevated Beclin‐1 level as well as ratio of LC3II/LC3I. Overexpression of SDF1 and Exo‐SDF1 inhibited apoptosis and autophagy of myocardial cells, but promoted tube formation of endothelial cells. The interference of PI3K signaling pathway promoted apoptosis and autophagy of myocardial cells, but inhibited tube formation of endothelial cells. SDF1 activated the PI3K signaling pathway. Exo‐SDF1 protected cardiac function of MI mice and inhibited myocardial tissue damage. This study provided evidence that SDF1 overexpression in MSCs‐derived exosomes inhibited autophagy of ischemic myocardial cells and promoted microvascular production of endothelial cells.
Stromal‐derived factor 1 (SDF1) overexpression in mesenchymal stem cells (MSCs)‐derived exosomes inhibited autophagy of ischemic myocardial cells and promoted microvascular production of endothelial cells.
► The Neoproterozoic magmatisms are determined in the Erguna Massif, NE China. ► The Neoproterozoic magmatisms can be subdivided into four stages: ∼851, ∼792, ∼762, and ∼737Ma. ► The Neoproterozoic ...magmatisms consist mainly of A-type granites and bimodal igneous rocks. ► The Neoproterozoic magmatisms reveal an extensional environment linked to the breakup of Rodinia.
In this paper, we discuss new zircon U–Pb ages, major and trace element analyses, and Hf isotope data for Neoproterozoic intrusive rocks in the Erguna Massif of NE China, in the eastern segment of the Central Asian Orogenic Belt (CAOB). Our aim is to elucidate the tectonic origin of the Erguna Massif and its relationship to the breakup of the Rodinia supercontinent. Zircons collected from a gabbro and five granitoids are euhedral–subhedral, and display striped absorption or fine-scale oscillatory growth zoning in CL images, implying a magmatic origin. Zircon U–Pb dating demonstrates that these rocks were emplaced in four stages during the Neoproterozoic, as follows: (1) ∼851Ma, an intrusive suite of syenogranites; (2) ∼792Ma, a bimodal igneous rock association of gabbros and gabbro–diorites, together with syenogranites; (3) ∼762Ma, a suite of granodiorites; and (4) ∼737Ma, another suite of syenogranites. These magmatic events are similar time-wise to those in the Tuva–Mongolia Massif and the northern Baikal region of the southern Siberian Craton, suggesting an affinity between the Erguna Massif and the southern margin of the Siberian Craton. The Neoproterozoic granitoids in the Erguna Massif have SiO2=68.72–78.36wt.%, Mg#=17–33, Al2O3=11.66–14.79wt.%, (Na2O+K2O)=7.46–9.27wt.%, and A/CNK=0.95–1.14; they are metaluminous to peraluminous, and similar to A-type granites. Moreover, these Neoproterozoic granitoids are enriched in light rare earth elements (LREEs) and large ion lithophile elements (LILEs), and depleted in heavy rare earth elements (HREEs) and high field strength elements (HFSEs, Nb, Ta, and Ti). Their zircon ɛHf (t) values mainly range from +2.7 to +8.1, which implies that their primary magmas were derived from partial melting of a depleted lower crust. In contrast, the Neoproterozoic gabbros and gabbro–diorites in the Erguna Massif have low SiO2 (50.43–51.53wt.%), relatively high Mg# (46–51), high Ni (22.5–23.8ppm), Cr (41.5–72.2ppm), and Co contents (28.9–32.5ppm), and are enriched in LILEs and LREEs but depleted in HREEs and HFSEs such as Nb and Ta. Their ɛHf (t) values range from +2.5 to +5.4. Together, these characteristics suggest the primary magmas of the gabbros and gabbro–diorites were derived by partial melting of a depleted mantle wedge that had been metasomatized by fluids derived from a subducted slab. In the context of the assembly and breakup of the Rodinia supercontinent, and Neoproterozoic magmatic events along the southern margin of the Siberian Craton, we conclude that the Neoproterozoic A-type granitoids, gabbros, and gabbro–diorites of the Erguna Massif formed in an extensional environment related to rifting, corresponding to the breakup of the Rodinia supercontinent.
•Spatial–temporal variations of Mesozoic volcanic rocks in NE China are studied.•Transformation from the Paleo-Asian Ocean to circum-Pacific regimes happened during T3 to J1.•Temporal effect of the ...Mongol–Okhotsk belt on NE China extended from at least J1 to K11.•K12 and K2 volcanisms in NE China were related to the subduction of the Paleo-Pacific Plate.
LA-ICP-MS zircon U–Pb ages and geochemical data are presented for the Mesozoic volcanic rocks in northeast China, with the aim of determining the tectonic settings of the volcanism and constraining the timing of the overprinting and transformations between the Paleo-Asian Ocean, Mongol–Okhotsk, and circum-Pacific tectonic regimes. The new ages, together with other available age data from the literature, indicate that Mesozoic volcanism in NE China can be subdivided into six episodes: Late Triassic (228–201Ma), Early–Middle Jurassic (190–173Ma), Middle–Late Jurassic (166–155Ma), early Early Cretaceous (145–138Ma), late Early Cretaceous (133–106Ma), and Late Cretaceous (97–88Ma). The Late Triassic volcanic rocks occur in the Lesser Xing’an–Zhangguangcai Ranges, where the volcanic rocks are bimodal, and in the eastern Heilongjiang–Jilin provinces where the volcanics are A-type rhyolites, implying that they formed in an extensional environment after the final closure of the Paleo-Asian Ocean. The Early–Middle Jurassic (190–173Ma) volcanic rocks, both in the Erguna Massif and the eastern Heilongjiang–Jilin provinces, belong chemically to the calc-alkaline series, implying an active continental margin setting. The volcanics in the Erguna Massif are related to the subduction of the Mongol–Okhotsk oceanic plate beneath the Massif, and those in the eastern Jilin–Heilongjiang provinces are related to the subduction of the Paleo-Pacific Plate beneath the Eurasian continent. The coeval bimodal volcanic rocks in the Lesser Xing’an–Zhangguangcai Ranges were probably formed under an extensional environment similar to a backarc setting of double-direction subduction. Volcanic rocks of Middle–Late Jurassic (155–166Ma) and early Early Cretaceous (145–138Ma) age only occur in the Great Xing’an Range and the northern Hebei and western Liaoning provinces (limited to the west of the Songliao Basin), and they belong chemically to high-K calc-alkaline series and A-type rhyolites, respectively. Combined with the regional unconformity and thrust structures in the northern Hebei and western Liaoning provinces, we conclude that these volcanics formed during a collapse or delamination of a thickened continental crust related to the evolution of the Mongol–Okhotsk suture belt. The late Early Cretaceous volcanic rocks, widely distributed in NE China, belong chemically to a low- to medium-K calc-alkaline series in the eastern Heilongjiang–Jilin provinces (i.e., the Eurasian continental margin), and to a bimodal volcanic rock association within both the Songliao Basin and the Great Xing’an Range. The volcanics in the eastern Heilongjiang–Jilin provinces formed in an active continental margin setting related to the subduction of the Paleo-Pacific Plate beneath the Eurasian continent, and the bimodal volcanics formed under an extensional environment related either to a backarc setting or to delamination of a thickened crust, or both. Late Cretaceous volcanics, limited to the eastern Heilongjiang–Jilin provinces and the eastern North China Craton (NCC), consist of calc-alkaline rocks in the eastern Heilongjiang–Jilin provinces and alkaline basalts in the eastern NCC, suggesting that the former originated during subduction of the Paleo-Pacific Plate beneath the Eurasian continent, whereas the latter formed in an extensional environment similar to a backarc setting. Taking all this into account, we conclude that (1) the transformation from the Paleo-Asian Ocean regime to the circum-Pacific tectonic regime happened during the Late Triassic to Early Jurassic; (2) the effect of the Mongol–Okhotsk suture belt on NE China was mainly in the Early Jurassic, Middle–Late Jurassic, and early Early Cretaceous; and (3) the late Early Cretaceous and Late Cretaceous volcanics can be attributed to the subduction of the Paleo-Pacific Plate beneath the Eurasian continent.
Abiotic stresses, such as drought and salt, are major environmental stresses, affecting plant growth and crop productivity. Plant bZIP transcription factors (bZIPs) confer stress resistances in harsh ...environments and play important roles in each phase of plant growth processes. In this research, 15 soybean bZIP family members were identified from drought-induced de novo transcriptomic sequences of soybean, which were unevenly distributed across 12 soybean chromosomes. Promoter analysis showed that these 15 genes were rich in ABRE, MYB and MYC
-acting elements which were reported to be involved in abiotic stress responses. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis indicated that 15
genes could be induced by drought and salt stress.
was significantly upregulated under stress conditions and thus was selected for further study. Subcellular localization analysis revealed that the GmbZIP2 protein was located in the cell nucleus. qRT-PCR results show that
can be induced by multiple stresses. The overexpression of
in
and soybean hairy roots could improve plant resistance to drought and salt stresses. The result of differential expression gene analysis shows that the overexpression of
in soybean hairy roots could enhance the expression of the stress responsive genes
,
,
,
and
. These results indicate that soybean
s played pivotal roles in plant resistance to abiotic stresses.
•Late Triassic bimodal igneous rocks are identified in Northeast China.•Late Triassic igneous rocks formed in an extensional environment.•The subduction of Paleo-Pacific Plate beneath Eurasia ...happened after Late Triassic.
This paper reports new zircon LA–ICP–MS and SIMS U–Pb ages and Hf isotope data, and whole-rock major and trace element data for Late Triassic igneous rocks of eastern Heilongjiang Province, NE China. These data provide new insights into the timing of the initiation of subduction of the Paleo-Pacific Plate beneath the Eurasian continent. The zircon U–Pb age data indicate that a suite of Late Triassic (228–202Ma) igneous rocks is present within the Songnen–Zhangguangcai Range Massif and within the western margin of the Khanka Massif. The Late Triassic igneous rocks within the Songnen–Zhangguangcai Range Massif consist of basalts, basaltic andesites, gabbro-diabases, and rhyolites, whereas coeval igneous rocks in the western margin of the Khanka Massif consist of hornblende gabbros and syenogranitic porphyries. These Late Triassic rocks constitute a geochemically bimodal igneous rock association that contains mafic rocks enriched in light rare earth elements (LREE) and large ion lithophile elements (LILE), and depleted in heavy rare earth elements (HREE) and high field strength elements (HFSE) such as Nb, Ta, Zr, Hf, and Ti. Zircons from these mafic rocks have εHf (t) values and TDM1 ages of +2.8 to +9.8 and 477–733Ma, respectively, suggesting that they formed from a primary magma generated by the partial melting of depleted lithospheric mantle material that had been previously modified by subduction-related fluids. The coeval felsic rocks are characterized by enrichments in LREEs and LILEs, and depletions in HREEs and HFSEs (including Nb, Ta, and Ti), and their zircons have εHf (t) values and TDM2 ages of +0.6 to +7.9 and 766 to 1461Ma, respectively, implying that these rocks were generated during the partial melting of juvenile crustal material. The Late Triassic bimodal igneous rocks in eastern Heilongjiang Province, combined with the regional geologic information, therefore record a post-orogenic extensional environment related to the final late Permian–Early Triassic closure of the Paleo-Asian Ocean. In addition, the presence of Late Triassic bimodal igneous rocks within the eastern margin of the Eurasian continent suggests that the subduction of the Paleo-Pacific Plate beneath the Eurasian continent began after the Late Triassic.
It is widely accepted that subduction of the Paleo-Pacific Plate beneath Eurasia began in the early Mesozoic. However, the tectonic nature and processes of the NE Asian continental margin in the Late ...Jurassic to early Early Cretaceous remain unclear. In this contribution, lithological, provenance, and metamorphic–deformation data are used to constrain the formation of Mesozoic accretionary complexes (AC) along the NE Asian continental margin and determine the tectonic relationship between the NE Asian continental margin and the Paleo-Pacific Plate in the Late Jurassic to early Early Cretaceous. The Mesozoic AC formed during the Late Jurassic (including the Raohe AC in NE China; the Khabarovsk, Samarka, and Taukha ACs in the Russian Far East; and the Mino–Tamba AC in Japan) and Early Cretaceous (including the Shimanto AC in Japan and the Kiselevka–Manoma AC in the Russian Far East). The Jurassic AC underwent a complex evolution, including the formation of seamounts, Middle–Late Jurassic terrigenous clastic sedimentation adjacent to the trench, collision of seamounts with Eurasia, northward migration of the AC, early Early Cretaceous terrigenous clastic sedimentation, a second period of accretion, and final emplacement. The earliest Mesozoic AC arrived at the trench at ca. 195 Ma. Combined with the occurrence of early Mesozoic calc-alkaline igneous rocks along the NE Asian continental margin, we suggest that subduction of the Paleo-Pacific Plate beneath Eurasia began in the Early Jurassic. Jurassic AC in Japan was affected by a regional high-P/T metamorphic event at 160 Ma, which might have been related to subduction–collision of seamounts with Eurasia at the trench. Ages and Hf isotopic compositions of detrital zircon grains from the Middle–Upper Jurassic and Cretaceous AC sandstones, together with paleontological and paleomagnetic data, indicate that Jurassic clastic sediments were sourced mainly from the South China Block (SCB), whereas the Lower Cretaceous sandstones were sourced from the eastern Central Asian Orogenic Belt (CAOB). The inferred northward migration of Jurassic AC in the Late Jurassic to early Early Cretaceous indicates that the boundary between the NE Asian continental margin and the Paleo-Pacific Plate was characterized by strike-slip tectonics at this time, likely due to a small angle of obliquity in the subduction of the Paleo-Pacific Plate beneath Eurasia. In the late Early Cretaceous, westward subduction of the Paleo-Pacific Plate beneath Eurasia resulted in the emplacement of the Raohe and Khabarovsk ACs at 137–130 Ma and the formation of ACs in the Russian Far East and Japan.
This study presents new secondary-ion mass spectrometry (SIMS) rutile and laser ablation–inductively coupled plasma–mass spectrometry (LA–ICP–MS) zircon U-Pb geochronological and whole-rock ...geochemical data for amphibolites of the Heilongjiang Complex, located within the Yilan area of NE China, to constrain the tectonic evolution of the Mudanjiang Ocean between the Songnen–Zhangguangcai Range and Jiamusi massifs. Magmatic zircon from amphibolites collected from the Yilan Marble Quarry yields a weighted mean 206Pb/238U age of 274 ± 2 Ma, which is interpreted as the protolithic age. Amphibolites from the Longlangang and Tuanshanzi areas yield rutile U-Pb ages of 177 ± 11 Ma and 172 ± 5 Ma, respectively, which are interpreted to reflect the cooling of these rocks below the closure temperature of Pb diffusion in rutile. Amphibolites from the Yilan Marble Quarry are enriched in light rare earth elements (LREEs) and depleted in high field strength elements (HFSEs; e.g., Nb, Ta and P) relative to large ion lithophile elements (LILEs). Amphibolites from the Longlangang and Tuanshanzi areas have relatively flat chondrite-normalized rare earth element (REE) patterns, and remarkable negative Nb and Ta anomalies. Moreover, all of the amphibolites from the Heilongjiang Complex in the Yilan area have tholeiitic and arc-type geochemical affinities. These amphibolites formed by similar petrogenetic processes, but from distinct mantle sources. The magmas that formed these units were generated by the partial melting of mantle sources metasomatized by subducted slab fluids, and the magma that formed the amphibolites within the Yilan Marble Quarry may have also incorporated sedimentary material. Mantle peridotite from the garnet-spinel transition zone is a possible source for the protolith of amphibolites in the Yilan Marble Quarry, and spinel-peridotites may have been the magma sources for the protoliths of amphibolites in the Longlangang and Tuanshanzi areas. Combining our data for amphibolites from the Heilongjiang Complex in the Yilan area with the results of previous research on Late Paleozoic–Early Mesozoic arc magmatism and metamorphism, we infer that the Late Paleozoic–Early Mesozoic tectonic evolution of the Mudanjiang Ocean was characterized by double-sided subduction. These data indicate that the Mudanjiang Ocean closed during the Jurassic (180–160 Ma).
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•Magmatic zircon from the amphibolite yielded protolithic age of 274 ± 2 Ma.•Rutile from the amphibolite yielded metamorphic ages of 177 ± 11 Ma and 172 ± 5 Ma.•The Mudanjiang Ocean closed during the Jurassic (180–160 Ma).
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