Duplicated chalcone synthase(CHS)genes modulate flavonoid production in tea plants in response to light stress

In tea plants,the abundant flavonoid compounds are responsible for the health benefits for the human body and define the astringent flavor profile.While the downstream mechanisms of flavonoid biosynthesis have been extensively studied,the role of chalcone synthase(CHS)in this secondary metabolic process in tea plants remains less clear.In this study,we compared the evolutionary profile of the flavonoid metabolism pathway and discovered that gene duplication of CHS occurred in tea plants.We identified three CsCHS genes,along with a CsCHS-like gene,as potential candidates for further functional investigation.Unlike the CsCHS-like gene,the CsCHS genes effectively restored flavonoid production in Arabidopsis chs-mutants.Additionally,CsCHS transgenic tobacco plants exhibited higher flavonoid compound accumulation compared to their wild-type counterparts.Most notably,our examination of promoter and gene expression levels for the selected CHS genes revealed distinct responses to UV-B stress in tea plants.Our findings suggest that environmental factors such as UV-B exposure could have been the key drivers behind the gene duplication events in CHS.

Camellia sinensis CsMYB4a participates in regulation of stamen growth by interaction with auxin signaling transduction repressor CsAUX/IAA4

Subgroup 4(Sg4)members of the R2R3-MYB are generally known as negative regulators of the phenylpropanoid pathway in plants.Our previous research showed that a R2R3-MYB Sg4 member from Camellia sinensis(CsMYB4a)inhibits expression of some genes in the phenylpropanoid pathway,but its physiological function in the tea plant remained unknown.Here,CsMYB4a was found to be highly expressed in anther and filaments,and participated in regulating filament growth.Transcriptome analysis and exogenous auxin treatment showed that the target of CsMYB4a might be the auxin signal pathway.Auxin/indole-3-acetic acid 4(AUX/IAA4),a repressor in auxin signal transduction,was detected from a yeast two-hybrid screen using CsMYB4a as bait.Gene silencing assays showed that both CsIAA4 and CsMYB4a regulate filament growth.Tobacco plants overexpressing CsIAA4 were insensitive to exogenous a-NAA,consistent with overexpression of CsMYB4a.Protein-protein interaction experiments revealed that CsMYB4a interacts with N-terminal of CsIAA4 to prevent CsIAA4 degradation.Knock out of the endogenous NtIAA4 gene,a CsIAA4 homolog,in tobacco alleviated filament growth inhibition and a-NAA insensitivity in plants overexpressing CsMYB4a.All results strongly suggest that CsMYB4a works synergistically with CsIAA4 and participates in regulation of the auxin pathway in stamen.

Downregulation of thioredoxin reductase 1 expression in the substantia nigra pars compacta of Parkinson's disease mice

Because neurons are susceptible to oxidative damage and thioredoxin reductase 1 is extensively distributed in the central nervous system and has antioxidant properties, we speculated that the enzyme may be involved in the pathogenesis of Parkinson＇s disease. A Parkinson＇s disease model was produced by intraperitoneal injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine into C57BL/6 mice. Real-time reverse transcription-PCR, western blot analysis and colorimetric assay showed that the levels of thioredoxin reductase 1 mRNA and protein were decreased, along with a significant reduction in thioredoxin reductase activity, in the midbrain of Parkinson＇s disease mice compared with normal mice. Immunohistochemical staining revealed that the number of thioredoxin reductase 1-positive neurons in the substantia nigra pars compacta of Parkinson＇s disease mice was significantly decreased compared with normal mice. These experimental findings suggest that the expression of thioredoxin reductase 1 in the substantia nigra pars compacta of Parkinson＇s disease mice is significantly decreased, and that the enzyme may be associated with disease onset.

Phosphate deficiency induced by infection promotes synthesis of anthracnose-resistant anthocyanin-3-O-galactoside phytoalexins in the Camellia sinensis plant

Tea(Camellia sinensis)is a well-known beverage crop rich in polyphenols with health benefits for humans.Understanding how tea polyphenols participate in plant resistance is beneficial to breeding resistant varieties and uncovering the resistance mechanisms.Here,we report that a Colletotrichum infection-induced‘pink ring’symptom appeared outside the lesion,which is highly likely to occur in resistant cultivars.By identifying morphological feature-specific metabolites in the pink ring and their association with disease resistance,and analysis of the association between metabolite and gene expression,the study revealed that the accumulation of anthocyanin-3-O-galactosides,red phytotoxin compounds resistant to anthracnose,plays a pivotal role in the hypersensitive response surrounding infection sites in tea plants.The results of genetic manipulation showed that the expression of CsF3Ha,CsANSa,CsUGT78A15,CsUGT75L43,and CsMYB113,which are involved in anthocyanin biosynthesis,is positively correlated with anthracnose-resistance and the formation of the pink ring.Further phosphorus quantification and fertilization experiments confirmed that phosphate deficiency caused by anthracnose is involved in the occurrence of the pink ring.Genetic manipulation studies indicated that altering the expression levels of Pi transporter proteins(CsPHT2-1,CsPHT4;4)and phosphate deprivation response transcription factors(CsWRKY75-1,CsWRKY75-2,CsMYB62-1)enhances resistance to anthracnose and the formation of the pink ring symptom in tea plants.This article provides the first evidence that anthocyanin-3-O-galactosides are the anthracnose-resistant phytoalexins among various polyphenols in tea plants,and this presents an approach for identifying resistance genes in tea plants,where genetic transformation is challenging.

Al-induced CsUGT84J2 enhances flavonol and auxin accumulation to promote root growth in tea plants

Although Al is not necessary or even toxic to most plants,it is beneficial for the growth of tea plants.However,the mechanism through which Al promotes root growth in tea plants remains unclear.In the present study,we found that flavonol glycoside levels in tea roots increased following Al treatment,and the Al-induced UDP glycosyltransferase CsUGT84J2 was involved in this mechanism.Enzyme activity assays revealed that rCsUGT84J2 exhibited catalytic activity on multiple types of substrates,including phenolic acids,flavonols,and auxins in vitro.Furthermore,metabolic analysis with UPLC-QqQ-MS/MS revealed significantly increased flavonol and auxin glycoside accumulation in CsUGT84J2-overexpressing Arabidopsis thaliana.In addition,the expression of genes involved in the flavonol pathway as well as in the auxin metabolism,transport,and signaling pathways was remarkably enhanced.Additionally,lateral root growth and exogenous Al stress tolerance were significantly improved in transgenic A.thaliana.Moreover,gene expression and metabolic accumulation related to phenolic acids,flavonols,and auxin were upregulated in CsUGT84J2-overexpressing tea plants but downregulated in CsUGT84J2-silenced tea plants.In conclusion,Al treatment induced CsUGT84J2 expression,mediated flavonol and auxin glycosylation,and regulated endogenous auxin homeostasis in tea roots,thereby promoting the growth of tea plants.Our findings lay the foundation for studying the precise mechanisms through which Al promotes the growth of tea plants.

Functional diversity of subgroup 5 R2R3-MYBs promoting proanthocyanidin biosynthesis and their key residues and motifs in tea plant

The tea plant(Camellia sinensis)is rich in polyphenolic compounds.Particularly,flavan-3-ols and proanthocyanidins(PAs)are essential for the flavor and disease-resistance property of tea leaves.The fifth subgroup of R2R3-MYB transcription factors comprises the primary activators of PA biosynthesis.This study showed that subgroup 5 R2R3-MYBs in tea plants contained at least nine genes belonging to the TT2,MYB5,and MYBPA types.Tannin-rich plants showed an expansion in the number of subgroup 5 R2R3-MYB genes compared with other dicotyledonous and monocot plants.The MYBPA-type genes of tea plant were slightly expanded.qRT–PCR analysis and GUS staining analysis of promoter activity under a series of treatments revealed the differential responses of CsMYB5s to biotic and abiotic stresses.In particular,CsMYB5a,CsMYB5b,and CsMYB5e responded to high-intensity light,high temperature,MeJA,and mechanical wounding,whereas CsMYB5f and CsMYB5g were only induced by wounding.Three genetic transformation systems(C.sinensis,Nicotiana tabacum,and Arabidopsis thaliana)were used to verify the biological function of CsMYB5s.The results show that CsMYB5a,CsMYB5b,and CsMYB5e could promote the gene expression of CsLAR and CsANR.However,CsMYB5f and CsMYB5g could only upregulate the gene expression of CsLAR but not CsANR.A series of site-directed mutation and domain-swapping experiments were used to verify functional domains and key amino acids of CsMYB5s responsible for the regulation of PA biosynthesis.This study aimed to provide insight into the induced expression and functional diversity model of PA biosynthesis regulation in tea plants.

Temporal and Spatial Evolution Characteristics of Habitat Quality in Kunming Based on Land Use Change

[Objectives]To analyze the change of urban habitat quality in different periods and study the influence of land use change on habitat quality,which plays an important role in regional sustainable development.[Methods]Taking Kunming as an example,based on land use change,InVEST model was used to evaluate the temporal and spatial evolution characteristics of habitat quality.[Results]During 2000-2020,cultivated land,grassland and woodland in Kunming decreased by 277.43,324.99 and 141.72 km 2,respectively;land use transfer presented obvious stage characteristics,with cultivated land,grassland and woodland changing into construction land as the main characteristics during 2005-2010,and 2015-2020.The average value of habitat quality index in Kunming decreased from 0.3119 to 0.3022,showing a downward trend as a whole;the spatial distribution pattern of habitat quality was"low in the middle and high around"(the high value areas of habitat quality are mainly distributed around Kunming,while the low value areas are mainly distributed in the urban aggregation areas of Kunming).[Conclusions]This study can provide theoretical support for future land use planning.

Roles of YABBY tanscription factors in the regulation of leaf development and abiotic stress responses in Camellia sinensis

The formation of leaf polarity directly determines the development of leaf spreading and type,and affects the physiological functions of photosynthesis,transpiration and stress resistance of plants.Many famous Chinese teas are highly dependent on the morphological characteristics and size of the tea leaves.To date,there have been few reports on the establishment of tea leaf polarity and leaf type development.The plant-specific transcription factor YABBY family gene has been reported to be involved in the formation of leaf polarity and growth.Herein we describe the isolation and functional characterization of transcription factor YABBY genes of the tea plant(Camellia sinensis).Six YABBY transcription factors were isolated from tea plants and classified into five clusters in the protein phylogenetic tree.Among them,CsFILa and CsFILb were highly expressed in buds and mature petals,and their expression decreased with the stage of leaf development.The Arabidopsis transgenic lines of CsFILa and CsFILb showed abaxial curled and long-narrow leaves.The above results indicated that CsFILa and CsFILb regulated the leaf growth of tea plants.The growth and expansion rate of leaf on the picked shoots decreased significantly after being plucked from tea plants,especially those suffering from drought stress.In this process,CsFILa expression levels decreased 60%−80%compared to the control.These data indicated YABBY genes play important roles in the leaf development of Camellia sinensis.

Removal of the C4-domain preserves the drought tolerance enhanced by CsMYB4a and eliminates the negative impact of this transcription factor on plant growth

The MYB4 transcription factor family regulates plant traits.However,their overexpression often results in undesirable side effects like growth reduction.We have reported a green tea(Camellia sinensis)MYB4 transcription factor(CsMYB4)that represses the phenylpropanoid and shikimate pathways and stunts plant growth and development.In the current study,we observed that in CsMYB4a transgenic tobacco(Nicotiana tabacum)plants,primary metabolism was altered,including sugar and amino acid metabolism,which demonstrated a pleiotropic regulation by CsMYB4a.The CsMYB4a transgenic tobacco plants had improved drought tolerance,which correlated to alterations in carbohydrate metabolism and an increase in proline content,as revealed by metabolic profiling and transcriptomic analysis.To mitigate the undesirable repressive side effects on plant traits,including dwarfism,shrunken leaves,and shorter roots of CsMYB4a transgenic plants,we deleted the C4 domain of CsMYB4a to obtain a CsMYB4a-DC4 variant and then overexpressed it in transgenic plants(CsMYB4a-DC4).These CsMYB4a-DC4 plants displayed a normal growth and had improved drought tolerance.Metabolite analysis demonstrated that the contents of carbohydrates and proline were increased in these transgenic plants.Our findings suggest that an approriate modification of TFs can generate novel crop traits,thus providing potential agricultural benefits and expanding its application to various crops.

Publisher Correction:Removal of the C4-domain preserves the drought tolerance enhanced by CsMYB4a and eliminates the negative impact of this transcription factor on plant growth

Publisher Correction:aBIOTECH https://doi.org/10.1007/s42994-024-00149-5 The original article has been updated to correct two errors introduced during production:In this article Xiu Li the same as Mingzhuo Li and Guoliang Ma should have been denoted as equally contributing authors.

Enjoy the most beautiful scene now:a memetic algorithm to solve two-fold time-dependent arc orienteering problem

Traditional route planners commonly focus on finding the shortest path between two points in terms of travel distance or time over road networks.However,in real cases,especially in the era of smart cities where many kinds of transportation-related data become easily available,recent years have witnessed an increasing demand of route planners that need to optimize for multiple criteria,e.g.,finding the route with the highest accumulated scenic score along(utility)while not exceeding the given travel time budget(cost).Such problem can be viewed as a variant of arc orienteering problem(AOP),which is well-known as an NP-hard problem.In this paper,targeting a more realistic AOP,we allow both scenic score(utility)and travel time(cost)values on each arc of the road network are time-dependent(2TD-AOP),and propose a memetic algorithm to solve it.To be more specific,within the given travel time budget,in the phase of initiation,for each population,we iteratively add suitable arcs with high scenic score and build a path from the origin to the destination via a complicate procedure consisting of search region narrowing,chromosome encoding and decoding.In the phase of the local search,each path is improved via chromosome selection,local-improvement-based mutation and crossover operations.Finally,we evaluate the proposed memetic algorithm in both synthetic and real-life datasets extensively,and the experimental results demonstrate that it outperforms the baselines.

Nitrogen-doped carbon-coated hollow SnS_(2)/NiS microflowers for high-performance lithium storage

Nitrogen-doped carbon-coated hollow SnS_(2)/NiS(SnS_(2)/NiS@N–C)microflowers were obtained using NiSn(OH)6 nanospheres as the template via a solventthermal method followed by the polydopamine coating and carbonization process.When served as an anode material for lithium-ion batteries,such hollow SnS_(2)/NiS@N–C microflowers exhibited a capacity of 403.5 mAh·g^(−1) at 2.0 A·g^(−1) over 200 cycles and good rate performance.The electrochemical reaction kinetics of this anode was analyzed,and the morphologies and structures of anode materials after the cycling test were characterized.The high stability and good rate performance were mainly due to bimetallic synergy,hollow micro/nanostructure,and nitrogen-doped carbon layers.The revealed excellent electrochemical energy storage properties of hollow SnS_(2)/NiS@N–C microflowers in this study highlight their potential as the anode material.

Maxwell方程的一种显式时间高精度有限差分方法

时间离散是Maxwell方程数值方法研究的重要内容,涉及方法的稳定性、收敛性、精度和计算复杂度等.本文利用Taylor多项式逼近理论,提出了一种时间离散新方法.该方法的特点是,显式计算,关于时间变量具有任意阶精度,容易与空间离散方法相结合.将该方法与空间离散的中心差分方法结合,提出求解三维Maxwell方程的一种显式有限差分方法,记为HAIT-FDTD (high accurate in time finite difference time domain).理论分析表明,新方法的精度关于空间二阶、关于时间M阶,其中M是多项式的次数并且在计算中可以选取任意值.利用Fourier分析证明了HAIT-FDTD稳定,并且稳定性条件不受CFL (Courant-Friedrichs-Lewy)条件的限制,同时还分析了数值弥散,证明了数值弥散关系式收敛于连续弥散关系式.数值实验给出了增长因子、数值弥散误差及对一个波导问题的计算和分析.计算结果验证了理论分析,并且发现HAIT-FDTD的数值弥散误差小于Yee格式和交替方向隐式时域有限差分方法(alternating direction implicit finite difference time domain, ADI-FDTD)的相应误差;近似保持能量守恒性和电磁场散度为零的性质;计算和程序实现简单,具有Yee格式的优点,并且时间可以采取大步长,具有ADI-FDTD的特点,比ADI-FDTD更节省CPU时间,适于长时间计算.

Multi-objective optimal allocation strategy for the energy internet in Huangpu District, Guangzhou, China

To improve the overall efficiency of the energy system,the basic structure for the energy internet of coordination and optimization of“generation-grid-load-storage”of Huangpu District,Guangzhou,China is designed,while the arrangement for the output of centralized and distributed energy module and energy storage are proposed.Taking economic benefit maximization,environmental benefit maximization and energy efficiency maximization as sub-objectives,the mathematical model of multi-objective optimal allocation and operation strategy of the energy internet is established considering supply-demand balance constraints,equipment characteristic constraints,operation mode constraints,and energy conditions constraints.The calculation results show that without considering the outsourced electricity,the balanced strategy,the economic development strategy,the environmental protection strategy,and the energy efficiency strategy are obtained by calculation,which are all superior to the traditional energy supply strategy.Moreover,considering the outsourced electricity,the proportion of outsourced electricity to total electricity is 19.8%,which is the system optimization of the energy internet under certain power demand.Compared with other strategies without outsourced electricity,the outsourced electricity strategy can have a certain emission reduction effect,but at the same time reduce the economic benefit.Furthermore,the huge difference in demand for thermal and cooling load between industrial and commercial areas results in the installed capacity of gas distributed energy stations in industrial areas being nearly twice as large as that in commercial areas.The distributed photovoltaic power generation is allocated according to the proportion of the installed roof areas of photovoltaic power generation system in residential,industrial,and commercial areas.

Splitting Finite Difference Methods on Staggered Grids for the Three-Dimensional Time-Dependent Maxwell Equations

In this paper,we study splitting numerical methods for the three-dimensional Maxwell equations in the time domain.We propose a new kind of splitting finitedifference time-domain schemes on a staggered grid,which consists of only two stages for each time step.It is proved by the energy method that the splitting scheme is unconditionally stable and convergent for problems with perfectly conducting boundary conditions.Both numerical dispersion analysis and numerical experiments are also presented to illustrate the efficiency of the proposed schemes.

Characteristics of Different Types of Prion Diseases—China’s Surveillance

This report briefly described the establishment and implementation of national surveillance for human prion disease(PrD)in China.Reported cases came from Chinese surveillance network for PrD.Immunohistochemistry,Western blot,enzyme-linked immunosorbent assay(ELISA),Polymerase Chain Reaction(PCR),and real-time quaking-induced conversion(RT-QuIC)tests were used for the samples of brain,cerebrospinal fluid(CSF),and blood.Diagnosis standard for the PrDs is based on the National Commission of Health(WS/T 562-2017).The study summarized major epidemiological,clinical and laboratory features of more than 2,100 diagnosed different types of Chinese PrD cases.Sporadic Creutzfeldt-Jacob disease(sCJD)is the predominant type of PrD(88.7%).19 different genotypes of genetic PrDs(gPrDs)were identified,accounting for about 11.3%of all PrDs,revealing ethno-relationships.No iatrogenic CJD(iCJD)and variant CJD(vCJD)was identified.The characteristics of different types of sCJD in China showed similar features as those reported globally,but gPrDs showed an obvious ethnorelationship.

Th17/Treg balance and factors related to autoimmune hepatitis

Background:Although Th17 cells and regulatory T cells play critical roles in autoimmune hepatitis,the balance between them in acute and chronic immune hepatitis is not well‐studied.The objective of this study was to explore the role of Th17/Treg balance in autoimmune hepatitis.Methods:Thirty female Wistar rats were randomly divided into the following three groups:acute model(AC),chronic model(CC),and healthy control(HC).Aspartate aminotransferase,alanine aminotransferase,and bilirubin levels were measured.Peripheral blood interleukin(IL)‐17,IL‐6,IL‐10,and transforming growth factor‐βcytokine levels were also assessed.Flow cytometry was used to detect changes in the Th17 cell and Treg cell frequency,and the Th17/Treg ratio was calculated.Results:The frequency of Th17 cells and Treg cells were both increased(p<0.05)and the Th17/Treg ratio was higher in the AC group compared with those in the HC group(p<0.05).Th17 cell levels were significantly lower and Treg cell levels were significantly higher in the CC group,compared with those in the AC group(p<0.05).In addition,the Th17/Treg ratio was lower in the CC group compared with that in the HC group(p<0.05).Conclusion:The Th17/Treg ratio was increased in the acute immune liver injury model and decreased in the chronic liver injury model.Th17/Treg imbalance may play a critical role in liver injury occurrence and development.

SnO_(2)nanotubes with N-doped carbon coating for advanced Li-ion battery anodes

Tin dioxide nanotubes with N-doped carbon layer(SnO_(2)/N-C NTs)were synthesized through a MoO3 nanorod-based sacrificial template method,dopamine polymerization and calcination process.Applied to the Li-ion battery,SnO_(2)/N-C NTs exhibited excellent electrochemical properties,with a first discharge capacity of 1722.3 mAh·g^(−1)at 0.1 A·g^(−1)and a high capacity of 1369.3 mAh·g^(−1)over 100 cycles.The superior electrochemical performance is ascribed to the N-doped carbon layer and tubular structure,which effectively improves the electrical conductivity of the composites,accelerates the migration of Li+and electrons,and alleviates the volume change of the anode to a certain extent.

Effect of soil surface roughness on emergence rate and yield of mechanized direct-seeded rapeseed based on 3D laser scanning

The quality of seedbed after sowing such as soil surface roughness is one of the key factors affecting the seedling emergence of rapeseed,which ultimately affected crop yield.However,the effect of soil surface roughness on seedling emergence and yield of rapeseed is still unclear.In this study,field experiments at the experimental site of Jianli and Shayang were carried out.Three treatments were designed:relative slow(M1),medium(M2),and fast(M3)forward speed of the unit.Soil surface roughness measured by a 3D laser scanner,seed quantity of the seeder,emergence rate and yield of rapeseed were determined to investigate the soil surface roughness effect on emergence rate and yield of rapeseed.The results showed that as the forward speed of the unit increased,the compartment surface became rougher.Compared with the M1 and M2 treatments,soil surface roughness under the M3 treatment increased by 36.5%and 9.8%,respectively.The actual seed quantity of the seeder under different treatments ranged from 3806.56 to 4158.18 g/hm2.The average error rate of the actual and theoretical seed quantity was less than 5%,which met the operational quality requirements for seeding rapeseed crops.As the forward speed of the unit increased,the actual seed quantity of the seeder gradually increased while the emergence rate and yield of rapeseed decreased.The seed quantity under the M3 treatment increased by 6.9%and 4.7%,while the emergence rate of rapeseed decreased by 3.3%and 2.0%,and the yield decreased by 23.2%and 13.1%,compared with the M1 and M2 treatments,respectively.Correlation analysis indicated that emergence rate and yield of rapeseed were negatively influenced by soil surface roughness.Considering rapeseed emergence rate,seed yield,and economic benefits,the M1 treatment was recommended.But considering the factor that the M1 treatment may reduce the unit operation efficiency,and thus resulting in lower cost of production,M2 could be recommended in actual farming.The results of this study laid a theoretical foundation for analyzing the relationship between the seedbed surface quality and seedling emergence and yield.

New Energy-Conserved Identities and Super-Convergence of the Symmetric EC-S-FDTD Scheme for Maxwell’s Equations in 2D

The symmetric energy-conserved splitting FDTD scheme developed in[1]is a very new and efficient scheme for computing theMaxwell’s equations.It is based on splitting the whole Maxwell’s equations and matching the x-direction and y-direction electric fields associated to the magnetic field symmetrically.In this paper,we make further study on the scheme for the 2D Maxwell’s equations with the PEC boundary condition.Two new energy-conserved identities of the symmetric EC-S-FDTD scheme in the discrete H^(1)-norm are derived.It is then proved that the scheme is unconditionally stable in the discrete H^(1)-norm.By the new energy-conserved identities,the super-convergence of the symmetric EC-S-FDTD scheme is further proved that it is of second order convergence in both time and space steps in the discrete H^(1)-norm.Numerical experiments are carried out and confirm our theoretical results.