Comparative metabolic profiling of Vitis amurensis and Vitis vinifera during cold acclimation

Vitis amurensis is a wild Vitis plant that can withstand extreme cold temperatures.However,the accumulation of metabolites during cold acclimation(CA)in V.amurensis remains largely unknown.In this study,plantlets of V.amurensis and V.vinifera cv.Muscat of Hamburg were treated at 4℃ for 24 and 72 h,and changes of metabolites in leaves were detected by gas chromatography coupled with time-of-flight mass spectrometry.Most of the identified metabolites,including carbohydrates,amino acids,and organic acids,accumulated in the two types of grape after CA.Galactinol,raffinose,fructose,mannose,glycine,and ascorbate were continuously induced by cold in V.amurensis,but not in Muscat of Hamburg.Twelve metabolites,including isoleucine,valine,proline,2-oxoglutarate,and putrescine,increased in V.amurensis during CA.More galactinol,ascorbate,2-oxoglutarate,and putrescine,accumulated in V.amurensis,but not in Muscat of Hamburg,during CA,which may be responsible for the excellent cold tolerance in V.amurensis.The expression levels of the genes encodingβ-amylase(BAMY),galactinol synthase(GolS),and raffinose synthase(RafS)were evaluated by quantitative reverse transcription-PCR.The expression BAMY(VIT_02s0012 g00170)and RafS(VIT_05s0077 g00840)were primarily responsible for the accumulation of maltose and raffinose,respectively.The accumulation of galactinol was attributed to different members of GolS in the two grapes.In conclusion,these results show the inherent differences in metabolites between V.amurensis and V.vinifera under CA.

New insights into the multiple magmatic fluid generations from scheelite in the Bastielieke W-polymetallic deposit,Chinese Altay(NW,China)

Scheelite is the main ore mineral in skarn-type tungsten(W-Mo,W-Sn,and W-Cu)deposits,and is also a good proxy for ore-fluid evolution and mineralization.The Bastielieke deposit is the first medium-size Wpolymetallic skarn deposit discovered in the Chinese(Xinjiang,NW China)Altay.Scheelite grains at Bastielieke are distributed in biotite granite,skarn and quartz-fluorite veins.They exhibit different textures,and can be divided into four types and six subtypes,including those in granite(Schm),prograde skarn(SchI),retrograde-altered rocks(SchII),and those in late-stage quartz-fluorite veins(SchIII).SchIa and SchIb were formed in the early and late prograde stage,respectively.SchI displays homogeneous texture,enrichments of light rare earth elements(LREEs)relative to heavy REEs(HREEs),and significantly negative Eu anomalies.SchIa has higher Sr-Mo contents and LREE/HREE than SchIb.SchII shows patchy texture by overgrowth and dissolution-reprecipitation,and can be subdivided into dark(SchIIa)and light(SchIIb)zone based in CL imaging.All SchII grains are LREE-enriched with negative Eu anomalies and relatively low LREE/HREE ratios.SchIIb has much higher W-Mo-Nb-Sr contents than SchIIa,which is ascribed to late-stage hydrothermal modifications.Schm and SchIII display homogeneous texture and similar MREE-enriched patterns,as well as very low Mo-W-Sr and different Nb contents.The texture and compositional variations in Bastielieke scheelites reveal that two magmatic fluids derived from different granitic magma reservoirs were involved in the mineralization.The earlier orefluid is relativly oxidized and has low HREE contents,forming the early prograde skarn-stage mineralization.Episodic influxes of later F-rich granitic magmatic fluids may have modified the earlier scheelite compositions,leading to multistage W enrichment and varying intragrain compositions.

Geological settings and metallogenesis of high-grade iron deposits in China

The predominant types of high-grade iron deposits in China include skarn,sedimentary metamorphic(banded ironformation,BIF-type),continental/submarine volcanic-hosted and magmatic Fe-Ti-Voxide deposits.Based on a comprehensive review of current studies on these deposits,this paper suggests that the oxygen concentration in atmosphere played an important role for the formation of BIFs,whereas the tectonic setting and deep magmatic differentiation processes are more important for the other types.Notably,both high temperature and high pressure experiments and melt inclusion studies indicate that during the differentiation,high temperature magmas could develop iron-rich magma via liquid immiscibility but not pure oxide melt("iron ore magma").Fe-P melt could be generated directly by liquid immiscibility under hydrous and oxidized condition.The formation of high-grade iron deposits is mostly associated with the processes related to multiple stages of superimposition,e.g.,desiliconization and iron enrichment,removal of impurity,and remobilization and re-precipitation of iron.According to the temporal evolution,the high-grade iron deposit could be divided into multi-episode superimposition type(temporally discontinuous mineralization)and multi-stage superimposition type(temporally continuous mineralization).The former is represented by the sedimentary metamorphic iron deposit,and the latter includes those related to magmatic-hydrothermal fluids(e.g.,skarn,volcanic-hosted and magmatic types).