4-methylumbelliferone (4-MU) enhances drought tolerance of apple by regulating rhizosphere microbial diversity and root architecture

The dwarfing rootstocks-mediated high-density apple orchard is becoming the main practice management.Currently,dwarfing rootstocks are widely used worldwide,but their shallow root system and drought sensitivity necessitate high irrigation requirements.Here,the root transcriptome and metabolome of dwarfing(M9-T337,a drought-sensitive rootstock)and vigorous rootstocks(Malus sieversii,a drought-tolerant species,is commonly used as a rootstock)showed that a coumarin derivative,4-Methylumbelliferon(4-MU),was found to accumulate significantly in the roots of vigorous rootstock under drought condition.When exogenous 4-MU was applied to the roots of dwarfing rootstock under drought treatment,the plants displayed increased root biomass,higher root-to-shoot ratio,greater photosynthesis,and elevated water use efficiency.In addition,diversity and structure analysis of the rhizosphere soil microbial community demonstrated that 4-MU treatment increased the relative abundance of putatively beneficial bacteria and fungi.Of these,Pseudomonas,Bacillus,Streptomyces,and Chryseolinea bacterial strains and Acremonium,Trichoderma,and Phoma fungal strains known for root growth,or systemic resistance against drought stress,were significantly accumulated in the roots of dwarfing rootstock after 4-MU treatment under drought stress condition.Taken together,we identified a promising compound—4-MU,as a useful tool,to strengthen the drought tolerance of apple dwarfing rootstock.

Discovery of Wolitu Pb-Zn deposit through geochemical prospecting under loess cover in Inner Mongolia, China

We report the finding of the Wolitu Pb-Zn deposit in Inner Mongolia, China, through a series of geochemical surveys. The Wolitu area, located in the loess-cover area in the Hure Banner, Tongliao City,Inner Mongolia, and neighboring the Horqin Sandy Land to the north, had no previous history of Pb-Zn mining or record of Pb-Zn mineralization. Our study identified a large Pb-Zn anomaly with potential zones of mineralization by stream sediment survey. Random rock sampling reveals limonitization at sporadic outcrops in the gullies. The high concentrations of Pb in the residual debris provided guidelines to fix the position for exploratory trench. Oxidized concealed orebodies were identified by trenching.Blind orebodies in veins hosted within the structural zone between slates and marbles of the upper Carboniferous Shizuizi Formation and the Permian granite were discovered by drilling. It is computed that the ore reserve may reach up to 540,000 tones with Pb grade of 1.27% and Zn of 1.9%. This case study is an excellent example for identifying potential polymetallic deposits in loess covered terrains using geochemical exploration.

Highly stabilized and lowly polarized Li anodes using a hybrid surface film with inner Li–Zn nucleation sites and outer LiF-rich protection texture

Lithium(Li)metal is the most promising anode for improving the energy density of currently commercialized Li-ion batteries.However,its practical application is limited due to its high reactivity to electrolytes,which induces severe electrolyte decomposition and Li-dendrite growth.Interphases are usually constructed on Li anode to address the above issue.Meanwhile,it is a big challenge to balance the stability and plating/stripping overpotential of Li anode.In this work,we report a novel strategy for constructing a highly stable and lowly polarized surface film on Li anode.A chemically and structurally unique film is formed by simply dropping a zinc trifluoromethanesulfonate[Zn(OTF)_(2)]and fluoroethylene carbonate(FEC)-containing solution onto Li anode.This unique film consists of inner nucleation sites and outer protection textures,mainly containing Li–Zn alloy and LiF/polymer,respectively.The former results from the preferential reduction of Zn(OTF)_(2),providing nucleation sites with low polarization for Li plating/stripping.In contrast,the latter arises from the subsequent reduction of FEC,providing protection for the underneath Li–Zn alloy and Li metal and ensuring the stability of Li anode.The Li anode with such a unique surface film exhibits excellent cycling stability and low plating/stripping overpotentials,which have been demonstrated using Li//Li symmetric and Li//LiFePO_(4)full cells.