Characteristic volatile components and transcriptional regulation of seven major tea cultivars(Camellia sinensis)in China

The volatiles in the young shoots of tea cultivars are the important material basis for the formation of tea aroma,but the cultivar-specific aroma and its molecular regulation are still lacking in research.In this study,the characteristic volatiles of seven tea cultivars in China were detected,and the results showed that the green tea cultivars'Fuding Dabaicha'(FDDB),'Longjing43'(LJ43),'Shuchazao'(SCZ),and'Baihaozao'(BHZ)were rich in(E)-3-hexenol,phenylethyl alcohol,phenylacetaldehyde,andβ-ionone.For oolong tea cultivars,the characteristic volatiles of'Tieguanyin'(TGY)were heptanal and eugenol,while the contents of(E)-β-ocimene,geraniol,and methyl salicylate were significantly increased in'Jinxuan'(JX).In addition,'Fujian Shuixian'(FJSX)has the highest content of esters,mainly jasmonolactone and dihydrojasmonolactone.Transcriptomic analysis showed that the different tea cultivars were significantly enriched in different levels of gene transcription in the three pathways related to aroma biosynthesis.Potential regulatory modules and genes of several characteristic volatiles were identified by WGCNA,among which CsbHLH(CsTGY12G0001520)may regulate the expression of CsTPS(CsTGY05G0001285)to directly affect the accumulation ofβ-caryophyllene in young shoots,while CsMYB(CsTGY01G0001203,CsTGY04G0001918,CsTGY06G0002545)may affect the synthesis of(Z)-3-hexenol and(E)-3-hexen-1-ol acetate by regulating the CsADH(CsTGY09G0001879).In addition,the transcription factors bHLH,WRKY,ERF,and MYB may be involved in the biosynthesis of linalool by regulating the expression of CsLIS/NES(CsTGY08G0001704,CsTGY08G0000359)genes individually or through interaction.These results revealed the characteristic volatiles and their key regulatory genes of seven tea cultivars,which will provide a theoretical basis for breeding and suitability research of tea cultivars.

Cell type-specific proteomics uncovers a RAF15-SnRK2.6/OST1 kinase cascade in guard cells

Multicellular organisms such as plants contain various cell types with specialized functions.Analyzing the characteristics of each cell type reveals specific cell functions and enhances our understanding of organization and function at the organismal level.Guard cells(GCs)are specialized epidermal cells that regulate the movement of the stomata and gaseous exchange,and provide a model genetic system for analyzing cell fate,signaling,and function.Several proteomics analyses of GC are available,but these are limited in depth.Here we used enzymatic isolation and flow cytometry to enrich GC and mesophyll cell protoplasts and perform in-depth proteomics in these two major cell types in Arabidopsis leaves.We identified approximately 3,000 proteins not previously found in the GC proteome and more than600 proteins that may be specific to GC.The depth of our proteomics enabled us to uncover a guard cell-specific kinase cascade whereby Raf15and Snf1-related kinase2.6(SnRK2.6)/OST1(open stomata 1)mediate abscisic acid(ABA)-induced stomatal closure.RAF15 directly phosphorylated SnRK2.6/OST1 at the conserved Ser175 residue in its activation loop and was sufficient to reactivate the inactive form of SnRK2.6/OST1.ABAtriggered SnRK2.6/OST1 activation and stomatal closure was impaired in raf15 mutants.We also showed enrichment of enzymes and flavone metabolism in GC,and consistent,dramatic accumulation of flavone metabolites.Our study answers the long-standing question of how ABA activates SnRK2.6/OST1 in GCs and represents a resource potentially providing further insights into the molecular basis of GC and mesophyll cell development,metabolism,structure,and function.

A critical review of vanadium-based electrode materials for rechargeable magnesium batteries

Rechargeable magnesium batteries(RMBs)are one of the most promising next-generation energy storage devices due to their high safety and low cost.With a large family and versatile advantageous structures,vanadium-based compounds are highly competitive as electrode materials of RMBs.This review summa-rizes the structural characteristics,electrochemical performance,and refinement methods of vanadium-based materials,including vanadium oxides,vanadium sulfides,vanadates,vanadium phosphates,and vanadium spinel compounds,as RMB cathodes.Although relatively less,vanadium-based materials as RMB anodes are also introduced.According to the application requirements of RMBs,present common strategies are concluded to improve the electrochemical performance of vanadium-based materials;the probably promising development directions are also proposed,which are not limited only to the elec-trode materials,but also the compatible electrolytes and separator materials.In the near future,RMBs are expected from their large-scale application,standing at the forefront of the energy storage era.