Mechanisms and regulation of organic acid accumulation in plant vacuoles

In fleshy fruits,organic acids are the main source of fruit acidity and play an important role in regulating osmotic pressure,pH homeostasis,stress resistance,and fruit quality.The transport of organic acids from the cytosol to the vacuole and their storage are complex processes.A large number of transporters carry organic acids from the cytosol to the vacuole with the assistance of various proton pumps and enzymes.However,much remains to be explored regarding the vacuolar transport mechanism of organic acids as well as the substances involved and their association.In this review,recent advances in the vacuolar transport mechanism of organic acids in plants are summarized from the perspectives of transporters,channels,proton pumps,and upstream regulators to better understand the complex regulatory networks involved in fruit acid formation.

Deciphering the impact of glucose signaling on fruit quality

Glucose is a preferred source of carbon and energy for plants.In addition to metabolic functions,glucose is a well-known signaling molecule that regulates plant growth and development through multiple pathways.In this review,the mechanisms by which glucose signaling regulates the accumulation of sugars and organic acids,as well as the ripening of fleshy fruit,are examined.An analysis of these complex molecular networks demonstrates the impact of glucose signal perception on fruit quality.

Modulating p-d orbital hybridization by CuO/Cu nanoparticles enables carbon nanofibers high cycling stability as anode for sodium storage

Carbon nanofibers(CNFs)have been extensively studied as anode materials for sodium-ion batteries due to their high conductivity,large aspect ratio and good electrochemical stability.The low specific capacity and low first cycle efficiency of CNFs,however,have hindered its practical application.Herein,we present a facile strategy to synthesize a novel CNFs decorated with Cu/CuO nanoparticles(Cu-CNFs)using magnetron sputtering method.Cu/CuO nanoparticles were uniformly distributed on the surface of CNFs.According to the density functional theory(DFT)calculation,Cu/CuO nanoparticles d-orbitals and CNFs p-orbitals present hybridization states,and the Na~+adsorption energy of the modified CNFs decreases from-2.14 to-2.97 eV.The Cu-CNFs composites exhibit excellent sodium storage properties,presenting a desirable initial Coulombic efficiency of 76%and a high specific reversible capacity of 300 mAh·g^(-1)at 0.1 A·g^(-1)after 400 cycles.Cu-CNFs anode has excellent cycling stability under high current density,maintaining a high capacity of 150 mAh·g^(-1)at 1 A·g^(-1)after 6000 cycles.Using magnetron sputtering to regulate the electronic structure provides a new thought for improving the electrochemical performance of carbon materials.

Optimized valence state of Co and Ni in high-entropy alloy for high active-stable OER

High entropy alloy(HEA)exhibits potential water-splitting properties but are limited by the high energy consumption from preparation.Moreover,the complex atomic distribution endows the electronic structure regulation of HEA to remain challenging.Herein,the nanoporous NiCuMnCoFe(np-NCMCF)HEA was prepared by the high-energy ball milling coupled with de-alloying method.The introduced Fe markedly increases the proportion of Ni^(3+)and Co^(3+).

Regulation of a vacuolar proton-pumping P-ATPase MdPH5 by MdMYB73 and its role in malate accumulation and vacuolar acidification

As the main organic acid in fruits,malate is produced in the cytoplasm and is then transported into the vacuole.It accumulates by vacuolar proton pumps,transporters,and channels,affecting the taste and flavor of fruits.Among the three types of proton pumps(V-ATPases,V-PPases,and P-ATPases),the P-ATPases play an important role in the transport of malate into vacuoles.In this study,the transcriptome data,collected at different stages after blooming and during storage,were analyzed and the results demonstrated that the expression of MdPH5,a vacuolar proton-pumping P-ATPase,was associated with both pre-and post-harvest malate contents.Moreover,MdPH5 is localized at the tonoplast and regulates malate accumulation and vacuolar pH.In addition,MdMYB73,an upstream MYB transcription factor of MdPH5,directly binds to its promoter,thereby transcriptionally activating its expression and enhancing its activity.In this way,MdMYB73 can also affect malate accumulation and vacuolar pH.Overall,this study clarifies how MdMYB73 and MdPH5 act to regulate vacuolar malate transport systems,thereby affecting malate accumulation and vacuolar pH.

GCH1 variants contribute to the risk and earlier age-at-onset of Parkinson's disease:a two-cohort case-control study

Background:Common and rare variants of guanosine triphosphate cyclohydrolase 1(GCH1)gene may play important roles in Parkinson's disease(PD).However,there is a lack of comprehensive analysis of GCH1 genotypes,especially in non-coding regions.The aim of this study was to explore the genetic characteristics of GCH1,including rare and common variants in coding and non-coding regions,in a large population of PD patients in Chinese mainland,as well as the phenotypic characteristics of GCH1 variant carriers.Methods:In the first cohort of this case-control study,we performed whole-exome sequencing in 1555 patients with early-onset or familial PD and 2234 healthy controls;then in the second cohort,whole-genome sequencing was performed in sporadic late-onset PD samples(1962 patients),as well as 1279 controls.Variants at target GCH1 regions were extracted,and then genetic and detailed phenotypic data were analyzed using regression models and the sequence kernel association test.We also performed a meta-analysis to correlate deleterious GCH1 variants with age at onset(AAO)in PD patients.Results:For coding variants,we identified a significant burden of GCH1 deleterious variants in early-onset or familial PD cases compared to controls(1.2%VS 0.1%,P<0.0001).In the analysis of possible regulatory variants in GCH1 non-coding regions,rs12323905(P=0.001,odds ratio=1.19,95%CI 1.07-1.32)was significantly associated with PD,and variant sets in untranslated regions and intron regions,GCH1 brain-specific expression quantitative trait loci,and two possible promoter/enhancer(GH14J054857 and GH14J054880)were suggestively associated with PD.Genotype phenotype correlation analysis revealed that the carriers of GCH1 deleterious variants manifested younger AAO(P<0.0001),and had milder motor symptoms,milder fatigue symptoms and more autonomic nervous dysfunctions.Meta-analysis of six studies demonstrated 6.4-year earlier onset in GCH1 deleterious variant carriers(P=0.0009).Conclusions:The results highlight the importance of deleterious variants and non-coding variants of GCH1 in PD in Chinese mainland and suggest that GCH1 mutation can influence the PD phenotype,which may help design experimental studies to elucidate the mechanisms of GCH1 in the pathogenesis of PD.