The members of the fourth subgroup of R2R3-MYB(Sg4 members)are well-known inhibitors of phenylpropanoid and lignin synthesis pathways.The C2 domain is closely related to the transcriptional inhibitory activity of Sg4 ...The members of the fourth subgroup of R2R3-MYB(Sg4 members)are well-known inhibitors of phenylpropanoid and lignin synthesis pathways.The C2 domain is closely related to the transcriptional inhibitory activity of Sg4 members.Phosphorylation modification enhances the transcriptional inhibitory activity of Sg4 members.Here,we identified a phosphorylation site on the C2 domain of Cs MYB4a from tea plants(Camellia sinensis).A mitogen-activated protein kinase(MAPK),named Cs MPK3-2,phosphorylated this site on the C2 domain of Cs MYB4a.Further experiments revealed that phosphorylation of Cs MYB4a weakened its ability to inhibit the gene expression of PAL,C4H,and 4CL in the phenylpropanoid pathway and activated the expression of transcription factor YABBY5,maintaining the adaxial-abaxial polarity of the leaf.Knocking out Nt YAB5 in Cs MYB4a transgenic tobacco partially repaired the leaf wrinkling phenotype caused by Cs MYB4a.The C1 domain exhibited an activation function when the C2 domain of Cs MYB4a was phosphorylated by Cs MPK3-2,causing this reversal phenomenon.These results enrich our understanding of the regulatory diversity of Sg4 members.展开更多
This work aims to compare the chemical composition and anti-inflammatory effects on RAW264.7 macrophages of Keemun black tea stems and leaves.A total of 50 volatile compounds were identified in tea stems and leaves,an...This work aims to compare the chemical composition and anti-inflammatory effects on RAW264.7 macrophages of Keemun black tea stems and leaves.A total of 50 volatile compounds were identified in tea stems and leaves,and aldehydes,alcohols,and esters were the main volatile compound categories.There were 11 key volatile compounds,including geraniol,benzeneacetaldehyde,methyl salicylate,linalool,etc.contributed to distinguishing the tea stems from the tea leaves.In the quantitative and liquid chromatography-mass spectrometry(LC-MS)-based metabolomics analysis,higher contents of amino acids,monosaccharides,and quinic acids were found in stems than those in leaves.Inversely,higher contents of tea pigments,flavan-3-ols,gallic acid,purine alkaloids,and flavonol glycosides were present in tea leaves than in stems.LC-MS-based metabolomics also revealed that organic acids were the most critical non-volatile compounds responsible for the differences between tea stems and leaves.Furthermore,tea stems had better inhibiting effects of pro-inflammatory cytokines(interleukin(IL)-1βand IL-6)in lipopolysaccharide-challenged RAW264.7 macrophages than tea leaves,while no significant differences exist between leaves and stems for inhibiting the secretion of tumor necrosis factorα(TNF-α)and NO.In conclusion,our results support using Keemun black tea stems as a novel source of anti-inflammatory compounds.展开更多
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 R2...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.展开更多
Drought stress is one of the main factors limiting yield in tea plants. The plant cell's ability to preserve K^+homeostasis is an important strategy for coping with drought stress. Plasma membrane H^+-ATPase in th...Drought stress is one of the main factors limiting yield in tea plants. The plant cell's ability to preserve K^+homeostasis is an important strategy for coping with drought stress. Plasma membrane H^+-ATPase in the mesophyll cell is important for maintaining membrane potential to regulate K^+transmembrane transport. However, no research to date has investigated the possible relationship between plasma membrane H^+-ATPase and mesophyll K^+retention in tea plants under drought and subsequent rehydration conditions. In our experiment, drought stress inhibited plasma membrane H^+-ATPase activities and induced net H^+influx, leading to membrane potential depolarization and inducing a massive K^+efflux in tea plant mesophyll cells. Subsequent rehydration increased plasma membrane H^+-ATPase activity and induced net H^+efflux, leading to membrane potential hyperpolarization and thus lowering K^+loss. A first downregulated and then upregulated plasma membrane H^+-ATPase protein expression level was also observed under drought and subsequent rehydration treatment, a finding in agreement with the change of measured plasma membrane H^+-ATPase activities. Taken together, our results suggest that maintenance of mesophyll K^+in tea plants under drought and rehydration is associated with regulation of plasma membrane H^+-ATPase activity.展开更多
Tea plants are sensitive to soil moisture deficit,with the level of soil water being a critical factor affecting their growth and quality.Arbuscular mycorrhizal fungi(AMF)can improve water and nutrient absorption,but ...Tea plants are sensitive to soil moisture deficit,with the level of soil water being a critical factor affecting their growth and quality.Arbuscular mycorrhizal fungi(AMF)can improve water and nutrient absorption,but it is not clear whether AMF can improve the photosynthetic characteristics of tea plants.A potted study was conducted to determine the effects of Claroideoglomus etunicatum on plant growth,leaf water status,pigment content,gas exchange,and chlorophyll fluorescence parameters in Camellia sinensis cv.Fuding Dabaicha under well-watered(WW)and drought stress(DS)conditions.Root mycorrhizal colonization and soil hyphal length were significantly reduced by the eightweek DS treatment.AMF inoculation displayed a significant increase in shoot and root biomass production.The relative water content,leaf water potential,nitrogen balance index,pigment content,maximum photometric effect(Fv/Fm,QY_max),and steady-state photometric effect Y(II)(QY_Lss)decreased dramatically,while the leaf water saturation deficit and steady-state non-photochemical fluorescence quenching(NPQ_Lss)generally increased under DS conditions.Mycorrhizal treatment induced significantly higher relative water content,leaf water potential,nitrogen balance index,pigment(chlorophyll,flavonoid,and anthocyanin)content,net photosynthesis rate,transpiration rate,stomatal conductance,intercellular CO_(2)concentration,QY_max,and QY_Lss;however,it resulted in a lower leaf water saturation deficit and NPQ_Lss under both WW and DS conditions,as compared with nonmycorrhizal plants.These results imply that AMF promoted tea plant growth and alleviated negative effects of DS by promoting gas exchange,regulating the water status of leaves,and regulating photosynthetic parameters.展开更多
Organic tea is more popular than conventional tea that originates from fertilized plants.Amino acids inorganic soils constitute a substantial pool nitrogen(N)available for plants.However,the amino-acid contents in soi...Organic tea is more popular than conventional tea that originates from fertilized plants.Amino acids inorganic soils constitute a substantial pool nitrogen(N)available for plants.However,the amino-acid contents in soils of tea plantations and how tea plants take up these amino acids remain largely unknown.In this study,we show that the amino-acid content in the soil of an organic tea plantation is significantly higher than that of a conventional tea plantation.Glutamate,alanine,valine,and leucine were the most abundant amino acids in the soil of this tea plantation.When 15 N-glutamate was fed to tea plants,it was efficiently absorbed and significantly increased the contents of other amino acids in the roots.We cloned seven CsLHT genes encoding amino-acid transporters and found that the expression of CsLHT1,CsLHT2,and CsLHT6 in the roots significantly increased upon glutamate feeding.Moreover,the expression of CsLHT1 or CsLHT6 in a yeast amino-acid uptake-defective mutant,22Δ10α,enabled growth on media with amino acids constituting the sole N source.Amino-acid uptake assays indicated that CsLHT1 and CsLHT6 are H^(+)-dependent high-and low-affinity amino-acid transporters,respectively.We further demonstrated that CsLHT1 and CsLHT6 are highly expressed in the roots and are localized to the plasma membrane.Moreover,overexpression of CsLHT1 and CsLHT6 in Arabidopsis significantly improved the uptake of exogenously supplied 15 N-glutamate and 15 N-glutamine.Taken together,our findings are consistent with the involvement of CsLHT1 and CsLHT6 in amino-acid uptake from the soil,which is particularly important for tea plants grown inorganic tea plantations.展开更多
Kunitz protease inhibitors(KPIs)are ubiquitous in plants and act as crucial compounds in defense responses against insect attack and pathogen infection.However,the influence of gene duplication on the postdivergence o...Kunitz protease inhibitors(KPIs)are ubiquitous in plants and act as crucial compounds in defense responses against insect attack and pathogen infection.However,the influence of gene duplication on the postdivergence of the CsKPI genes involved in biotic stresses in tea plant is not well known.Here,we identified three CsKPI genes from tea plant(Camellia sinensis)and characterized their expression and evolutionary patterns among plant species.We found that CsKPI1,CsKPI2,and CsKPI3 diverged from their common ancestor 72.94 million years ago(MYA),and the tandem duplication of CsKPI2 and CsKPI3 occurred 26.78 MYA.An in vitro protein assay showed that the three CsKPI proteins were functional and inhibited the production of p-nitroanilide(PNA)from an artificial substrate.The three CsKPI-GFP fusion proteins localized to the cytoplasm.We showed that salicylic acid(SA)and transcripts of CsKPI2 and CsKPI3 significantly accumulated after infection with Glomerella cingulata.The application of exogenous SA stimulated the high expression of both CsKPI2 and CsKPI3 by activating cis-elements within their promoters.Under Ectropis oblique attack,CsKPI1 expression and jasmonic acid(JA)levels were more abundant in both insect-damaged leaf tissues and undamaged neighboring leaves.The application of jasmonic acid methyl ester elicited high expression levels of CsKPI1,suggesting that CsKPI1 accumulation requires JA production in tea plant.The overall findings suggest that the transcriptional divergence of KPI genes after duplication led to the specialized role of CsKPI1 in the physiological response to insect stress;the functional conservation between CsKPI2 and CsKPI3 confers resistance to pathogen infection in tea plant.展开更多
Tea processed from albino/etiolated tea shoots is favored by consumers because of its high theanine accumulation.To explore why theanine accumulates highly in new shoots of albino/etiolated tea cultivars,we compared t...Tea processed from albino/etiolated tea shoots is favored by consumers because of its high theanine accumulation.To explore why theanine accumulates highly in new shoots of albino/etiolated tea cultivars,we compared theanine content in shoots and roots of albino/etiolated and common green tea cultivars.Results suggested that high theanine accumulation in albino/etiolated tea shoots was likely not caused by higher theanine biosynthesis in roots.Further analyses suggested that CsAlaDC-catalyzed ethylamine biosynthesis and CsGOGAT1-catalyzed glutamate biosynthesis were more active,and CsGGT2-catalyzed theanine catabolism was weaker in new shoots of these albino/etiolated tea plant cultivars.Therefore,the high theanine accumulation in albino/etiolated shoots is probably contributed by the strong theanine biosynthesis and weak catabolism in new shoots.These findings provided more comprehensive insights into the high accumulation of theanine in new shoots of albino/etiolated tea cultivars,and the knowledge can be used in plant breeding for new cultivars with higher theanine accumulation.展开更多
Self-incompatibility(SI)is a kind of plant fertilization obstacle,which can prevent the harmful effects of inbreeding decline,but it hinders the breeding of inbred lines.Tea plants have SI and long-term cross-pollinat...Self-incompatibility(SI)is a kind of plant fertilization obstacle,which can prevent the harmful effects of inbreeding decline,but it hinders the breeding of inbred lines.Tea plants have SI and long-term cross-pollination,which limits the progress of genetic research and variety improvement.However,the mechanism of SI in tea plants is still a mystery.Herein,microscopic observation showed that the pollen tube could pass through the base of style and enter the ovary cavity after 48 h of self-pollination at different flowering stages,and the SI intensity at bud stage and full bloom stage was lower than initial bloom stage.RNA-seq analysis showed that 1,463 and 1,409 differentially expressed genes(DEGs)were associated with low SI at bud stage and full bloom stage,respectively,and 507 DEGs were associated with SI at initial bloom stage.The results of qRT-PCR validation of 20 DEGs were consistent with the RNA-seq data.Furthermore,CsRNS,CsSRKL5 and CsSRKL8 specifically expressed in style,which may be related to the low SI at bud stage,and three CsACC genes may be related to the low SI at full bloom stage.The results provide useful information for understanding the mechanism of SI in tea plants.展开更多
The WRKY gene family is most widely known as being the key plant transcription factor family involved in various stress responses and affecting plant growth and development.In this study,a total of 86 members of the C...The WRKY gene family is most widely known as being the key plant transcription factor family involved in various stress responses and affecting plant growth and development.In this study,a total of 86 members of the CsWRKY genes were identified from the tea plant genome.Most of these genes contain several important Cis-regulatory elements in the promoter regions associated with multiple stress-responses.These genes were further classified into three groups,I,II,and III,each with 21,58,and 7 members,respectively.We showed evidence that tandem duplications,but not the whole genome duplication,are likely to drive the amplification of CsWRKY genes in tea plants.All the 86 CsWRKY genes showed differential expression patterns either in different tissues,or under exposure to diverse abiotic stresses such as drought,cold acclimation,and MeJA treatments.Additionally,the functional roles of two genes,CsWRKY29 and CsWRKY37,were examined under cold stress;and the silencing of these genes resulted in tea plant phenotypes susceptible to cold stress.Moreover,transgenic Arabidopsis lines overexpressing CsWRKY29 and CsWRKY37 genes showed higher survival rates and lower malondialdehyde levels under freezing treatment than the wild type plants.The core findings from this work provide valuable evolutionary pattern of WRKY gene family and underpinning the underlying regulatory roles of CsWRKY29 and CsWRKY37 from tea plants that conferred cold tolerance in transgenic Arabidopsis plants.展开更多
Tea trichomes contribute significantly to tea flavors by providing diverse and specific flavor-determining metabolites,including catechins,caffeine,theanine,and volatiles.However,not much is known about the physiologi...Tea trichomes contribute significantly to tea flavors by providing diverse and specific flavor-determining metabolites,including catechins,caffeine,theanine,and volatiles.However,not much is known about the physiological functions of tea trichomes in tea plant adaptation to complex environments,nor the trichome development.Tea trichomes not only build up chemical defenses,but also act as the first physical barrier protecting herbivore attacks,reflecting high light and UV-B radiation,and preventing water loss.Moreover,transcriptome profiling on the tea trichomes compared with the trichome-removed leaves also showed that tea trichomes highly expressed numerous defense-related genes involved in protection from high light and UV-B radiation,cold stress,disease resistance signal transduction,anti-herbivore or anti-abiotic peptide biosynthesis,and other defense responses.Several pieces of experimental evidence supported the notes,highlighting the roles of tea trichomes in plant defenses against both abiotic and biotic stresses.The study provides fresh insights into the multiple protective functions of tea trichome for tea plant adaptation to harsh environments.The new understanding on tea trichomes could benefit the development of better breading strategy for new tea varieties with greater adaption and tolerance to changing environmental challenges.展开更多
Osmotic stress caused by low-temperature,drought and salinity was a prevalent abiotic stress in plant that severely inhibited plant development and agricultural yield,particularly in tea plant.Jasmonic acid(JA)is an i...Osmotic stress caused by low-temperature,drought and salinity was a prevalent abiotic stress in plant that severely inhibited plant development and agricultural yield,particularly in tea plant.Jasmonic acid(JA)is an important phytohormone involving in plant stress.However,underlying molecular mechanisms of JA modulated osmotic stress response remains unclear.In this study,high concentration of mannitol induced JA accumulation and increase of peroxidase activity in tea plant.Integrated transcriptome mined a JA signaling master,MYC2 transcription factor is shown as a hub regulator that induced by mannitol,expression of which positively correlated with JA biosynthetic genes(LOX and AOS)and peroxidase genes(PER).CsMYC2 was determined as a nuclei-localized transcription activator,furthermore,ProteinDNA interaction analysis indicated that CsMYC2 was positive regulator that activated the transcription of CsLOX7,CsAOS2,CsPER1 and CsPER3via bound with their promoters,respectively.Suppression of CsMYC2 expression resulted in a reduced JA content and peroxidase activity and osmotic stress tolerance of tea plant.Overexpression of CsMYC2 in Arabidopsis improved JA content,peroxidase activity and plants tolerance against mannitol stress.Together,we proposed a positive feedback loop mediated by CsMYC2,CsLOX7 and CsAOS2 which constituted to increase the tolerance of osmotic stress through fine-tuning the accumulation of JA levels and increase of POD activity in tea plant.展开更多
Tea is among the world’s most widely consumed non-alcoholic beverages and possesses enormous economic,health,and cultural values.It is produced from the cured leaves of tea plants,which are important evergreen crops ...Tea is among the world’s most widely consumed non-alcoholic beverages and possesses enormous economic,health,and cultural values.It is produced from the cured leaves of tea plants,which are important evergreen crops globally cultivated in over 50 countries.Along with recent innovations and advances in biotechnologies,great progress in tea plant genomics and genetics has been achieved,which has facilitated our understanding of the molecular mechanisms of tea quality and the evolution of the tea plant genome.In this review,we briefly summarize the achievements of the past two decades,which primarily include diverse genome and transcriptome sequencing projects,gene discovery and regulation studies,investigation of the epigenetics and noncoding RNAs,origin and domestication,phylogenetics and germplasm utilization of tea plant as well as newly developed tools/platforms.We also present perspectives and possible challenges for future functional genomic studies that will contribute to the acceleration of breeding programs in tea plants.展开更多
Myriad evidence attests to the health-promoting benefits of tea drinking.While there are multiple factors of tea influencing the effective biological properties,tea polyphenols are the most significant and valuable co...Myriad evidence attests to the health-promoting benefits of tea drinking.While there are multiple factors of tea influencing the effective biological properties,tea polyphenols are the most significant and valuable components.The chemical characterization and physical characteristics of tea polyphenols have been comprehensively studied over the previous years.Still the emergence of new chemistry in tea,particularly the property of scavenging reactive carbonyl species(RCS)and the newly discovered flavoalkaloid compounds,has drawn increasing attention.In this review,we summarize recent findings of a new class of compounds in tea-flavonoid alkaloids(flavoalkaloids),which exist in fresh tea leaves and can be generated during the process of post-harvesting,and also postulate the formation mechanism of flavoalkaloids between catechins and theanine-derived Strecker aldehyde.Additionally,we detail the up-to-date research results of tea polyphenols regarding their ability to trap RCS and their in vivo aminated metabolites to suppress advanced glycation ends products(AGEs).We further raise questions to be addressed in the near future,including the synthetic pathways for the generation of flavoalkaloids and AGEs in fresh tea leaves before processing and the concentrations of tea polyphenols that affect their RCS scavenging capability due to their pro-oxidant nature.More intensive research is warranted to elucidate the mechanisms of action underlying the biological activity of flavoalkaloids and the pharmacological application of tea polyphenols in scavenging RCS and impeding detrimental AGEs.展开更多
Under high light conditions or UV radiation,tea plant leaves produce more flavonols,which contribute to the bitter taste of tea;however,neither the flavonol biosynthesis pathways nor the regulation of their production...Under high light conditions or UV radiation,tea plant leaves produce more flavonols,which contribute to the bitter taste of tea;however,neither the flavonol biosynthesis pathways nor the regulation of their production are well understood.Intriguingly,tea leaf flavonols are enhanced by UV-B but reduced by shading treatment.CsFLS,CsUGT78A14,CsMYB12,and CsbZIP1 were upregulated by UV-B radiation and downregulated by shading.CsMYB12 and CsbZIP1 bound to the promoters of CsFLS and CsUGT78A14,respectively,and activated their expression individually.CsbZIP1 positively regulated CsMYB12 and interacted with CsMYB12,which specifically activated flavonol biosynthesis.Meanwhile,CsPIF3 and two MYB repressor genes,CsMYB4 and CsMYB7,displayed expression patterns opposite to that of CsMYB12.CsMYB4 and CsMYB7 bound to CsFLS and CsUGT78A14 and repressed their CsMYB12-activated expression.While CsbZIP1 and CsMYB12 regulated neither CsMYB4 nor CsMYB7,CsMYB12 interacted with CsbZIP1,CsMYB4,and CsMYB7,but CsbZIP1 did not physically interact with CsMYB4 or CsMYB7.Finally,CsPIF3 bound to and activated CsMYB7 under shading to repress flavonol biosynthesis.These combined results suggest that UV activation and shading repression of flavonol biosynthesis in tea leaves are coordinated through a complex network involving CsbZIP1 and CsPIF3 as positive MYB activators and negative MYB repressors,respectively.The study thus provides insight into the regulatory mechanism underlying the production of bitter-tasting flavonols in tea plants.展开更多
Roasting is a common manufacture technology for processing various teas.It is not only used in decreasing the water content of finished tea,but also improving the flavor of teas.In the present study,the roasted and no...Roasting is a common manufacture technology for processing various teas.It is not only used in decreasing the water content of finished tea,but also improving the flavor of teas.In the present study,the roasted and non-roasted teas were compared by liquid-chromatography mass spectrometry and sensory evaluation.The roasted tea tasted less bitter and astringent.The content of main galloylated and simple catechins,caffeine and theobromine in roasted were significantly lower than non-roasted teas.Targeted taste-compounds metabolomics revealed that(-)-epigallocatechin gallate,kaempferol-glucose-rhamnose-glucose and(-)-epicatechin gallate were main contributors tightly correlated to astringent intensity.Flavonol glycosides including kaempferol-glucose,quercetin-glucose,kaempferol-glucose-rhamnose-glucose,and quercetin-glucose-rhamnose-glucose in roasted teas were also significantly less than non-roasted teas.To study the chemical changes during roasting,tea with a strong astringency was roasted under 80,100,120,140,and 160°C.With the increase of roasting temperature,the bitter and astringent intensity of tea was gradually decreased,but the main astringent compounds including(-)-epigallocatechin,(-)-epigallocatechin gallate and kaempferol/quercetin glycosides were irregularly varied with temperature.The Pearson correlation coefficient analysis suggested procyanidin B2,coumaroylquinic acids and gallotannins were tightly correlated to the astringent and bitter perceptions,while N-ethyl-2-pyrrolidonesubstituted flavan-3-ols were negatively correlated.展开更多
The growth and yield of tea plants are seriously limited by drought stress.Fatty acid desaturases(FADs)contribute to the mediation of membrane fluidity in response to different stresses,although the role ofω-3 FAD(Om...The growth and yield of tea plants are seriously limited by drought stress.Fatty acid desaturases(FADs)contribute to the mediation of membrane fluidity in response to different stresses,although the role ofω-3 FAD(Omega-3fatty acid desaturase)-mediated damage induced by drought stress in tea plants is poorly understood.In this study,drought stress significantly promoted the synthesis of C18:3(linolenic acid)and the expression level of CsFAD3.Yeast experiments further demonstrated that CsFAD3 can convert C18:2 to C18:3,and that the 35S:GFP-CsFAD3fusion protein was localized in the endoplasmic reticulum of Nicotiana benthamiana cells.CsFAD3-silenced tea leaves exhibited poor drought tolerance,with a lower F_(v)/F_(m)and a higher malondialdehyde(MDA)content than the control plants.However,transgenic 35S:CsFAD3 Arabidopsis plants showed the opposite phenotypes.In addition,the jasmonic acid(JA)content and the expression levels of CsLOX2,CsLOX4,CsAOS,CsAOC3 and CsOPR2 were significantly reduced in CsFAD3-silenced leaves under drought stress.However,no substantial difference in the salicylic acid(SA)content was detected under normal or drought conditions.An analysis of Atcoi1(JA receptor)or Atnpr1(SA receptor)mutant Arabidopsis plants in 35S:CsFAD3 backgrounds further revealed that knockout of Atcoi1impaired the drought-tolerant phenotypes of CsFAD3 overexpression lines.Therefore,this study demonstrated that CsFAD3 plays a crucial role in drought tolerance by mediating JA pathways.展开更多
Among six major types of tea(white,green,oolong,yellow,black,and dark teas)from Camellia sinensis,oolong tea,a semi-fermented tea,with its own unique aroma and taste,has become a popular consumption as indicated by th...Among six major types of tea(white,green,oolong,yellow,black,and dark teas)from Camellia sinensis,oolong tea,a semi-fermented tea,with its own unique aroma and taste,has become a popular consumption as indicated by the increasing production.Representing the characteristic flavonoids of oolong tea,theasinensins are dimeric flavan-3-ols.Many recent studies have indicated that oolong tea and theasinensins possess several health benefit properties.We consider it significant and necessary to have a comprehensive review in the recent advances of oolong tea.Therefore,the aim of the present review is to provide a new perspective on oolong tea and its characteristic phytochemicals,theasinensins associated with health benefits,molecular action pathway,and chemical mechanism of theasinensin formation from scientific evidences available on the literature.Furthermore,the chemical characterization of the oxidation products and the model oxidation system to the chemical changes of theasinensins are also discussed.展开更多
The carotenoid-derived volatileβ-ionone makes an important contribution to tea fragrance.Here,we qualitatively and quantitatively analysed 15 carotenoids in tea leaves of 13 cultivars by UHPLC-APCI-MS/MS.The 13 culti...The carotenoid-derived volatileβ-ionone makes an important contribution to tea fragrance.Here,we qualitatively and quantitatively analysed 15 carotenoids in tea leaves of 13 cultivars by UHPLC-APCI-MS/MS.The 13 cultivars were divided into two groups by PCA(Principal Component Analysis)clustering analysis of their carotenoid content,and OPLS-DA(Orthogonal projections to latent structures)indicated that the levels ofβ-carotene(VIP=2.89)and lutein(VIP=2.30)were responsible for much of the variation between the two groups.Interestingly,theβ-carotene toβ-ionone conversion rates in Group 1 were higher than in Group 2,while theβ-carotene content was significantly lower in Group 1 than in Group 2.Theβ-ionone content was significantly higher in Group 1.Pearson Correlation Coefficient calculation between the transcription level of candidate genes(CsCCD1 and CsCCD4)and the accumulation ofβ-ionone indicated that CsCCD1 may involve in the formation ofβ-ionone in 13 cultivars.Prokaryotic expression and in vitro enzyme activity assays showed that‘Chuanhuang 1’had an amino acid mutation in carotenoid cleavage dioxygenases 1(CsCCD1)compared with‘Shuchazao’,resulting in a significantly higherβ-ionone content in‘Chuanhuang 1’.Sequence analysis showed that‘Chuanhuang 1’and‘Huangdan’had different CsCCD1 promoter sequences,leading to significantly higher CsCCD1 expression andβ-ionone accumulation in‘Chuanhuang 1’.These results indicated that the promoter and coding sequence diversity of CsCCD1 might contribute to the differential accumulation ofβ-ionone in different tea cultivars.展开更多
Flavonoids are critical secondary metabolites that determine the health benefits and flavor of tea,while chlorophylls are important contributors to the appearance of tea.However,transcription factors(TFs)that can inte...Flavonoids are critical secondary metabolites that determine the health benefits and flavor of tea,while chlorophylls are important contributors to the appearance of tea.However,transcription factors(TFs)that can integrate both chlorophyll biosynthesis and flavonoid accumulation in response to specific light signals are rarely identified.In this study,we report that the GOLDEN 2-LIKE TF pair,CsGLK1 and CsGLK2,orchestrate UV-B-induced responses in the chlorophyll biosynthesis and flavonoid accumulation of tea leaves.The absence of solar UV-B reduced the transcriptional expression of CsGLKs in the tea leaves and was highly correlated with a decrease in flavonoid levels(especially flavonol glycosides)and the expression of genes and TFs involved in chlorophyll biosynthesis and flavonoid accumulation.In vivo and in vitro molecular analyses showed that CsGLKs could be regulated by the UV-B signal mediator CsHY5,and could directly bind to the promoters of gene and TF involved in light-harvesting(CsLhcb),chlorophyll biosynthesis(CsCHLH,CsHEMA1,and CsPORA),and flavonoid accumulation(CsMYB12,CsFLSa,CsDFRa,and CsLARa),eventually leading to UV-B-induced responses in the chlorophylls and flavonoids of tea leaves.Furthermore,UV-B exposure increased the levels of total flavonoids,CsGLK1 protein,and expression of CsGLKs and target genes in the tea leaves.These results indicate that CsGLKs may modulate tea leaf characteristics by regulating chlorophyll biosynthesis and flavonoid accumulation in response to solar UV-B.As the first report on UV-B-induced changes in flavonoid and chlorophyll regulation mediated by CsGLKs,this study improves our understanding of the environmental regulations regarding tea quality and sheds new light on UV-B-induced flavonoid responses in higher plants.展开更多
基金supported by the joint funds of National Natural Science Foundation of China(Grant Nos.U21A20232,32372756,32072621)。
文摘The members of the fourth subgroup of R2R3-MYB(Sg4 members)are well-known inhibitors of phenylpropanoid and lignin synthesis pathways.The C2 domain is closely related to the transcriptional inhibitory activity of Sg4 members.Phosphorylation modification enhances the transcriptional inhibitory activity of Sg4 members.Here,we identified a phosphorylation site on the C2 domain of Cs MYB4a from tea plants(Camellia sinensis).A mitogen-activated protein kinase(MAPK),named Cs MPK3-2,phosphorylated this site on the C2 domain of Cs MYB4a.Further experiments revealed that phosphorylation of Cs MYB4a weakened its ability to inhibit the gene expression of PAL,C4H,and 4CL in the phenylpropanoid pathway and activated the expression of transcription factor YABBY5,maintaining the adaxial-abaxial polarity of the leaf.Knocking out Nt YAB5 in Cs MYB4a transgenic tobacco partially repaired the leaf wrinkling phenotype caused by Cs MYB4a.The C1 domain exhibited an activation function when the C2 domain of Cs MYB4a was phosphorylated by Cs MPK3-2,causing this reversal phenomenon.These results enrich our understanding of the regulatory diversity of Sg4 members.
基金supported by the Natural Science Foundation of China(32122079,32072633)Earmarked Fund for China Agriculture Research System(CARS-19)+2 种基金Anhui Key Research and Development Plan(202104b11020001)Young Elite Scientist Sponsorship Program by National CAST(2016QNRC001)High-level Introduced Talent Sponsorship Program by Anhui Agricultural University(rc352203)。
文摘This work aims to compare the chemical composition and anti-inflammatory effects on RAW264.7 macrophages of Keemun black tea stems and leaves.A total of 50 volatile compounds were identified in tea stems and leaves,and aldehydes,alcohols,and esters were the main volatile compound categories.There were 11 key volatile compounds,including geraniol,benzeneacetaldehyde,methyl salicylate,linalool,etc.contributed to distinguishing the tea stems from the tea leaves.In the quantitative and liquid chromatography-mass spectrometry(LC-MS)-based metabolomics analysis,higher contents of amino acids,monosaccharides,and quinic acids were found in stems than those in leaves.Inversely,higher contents of tea pigments,flavan-3-ols,gallic acid,purine alkaloids,and flavonol glycosides were present in tea leaves than in stems.LC-MS-based metabolomics also revealed that organic acids were the most critical non-volatile compounds responsible for the differences between tea stems and leaves.Furthermore,tea stems had better inhibiting effects of pro-inflammatory cytokines(interleukin(IL)-1βand IL-6)in lipopolysaccharide-challenged RAW264.7 macrophages than tea leaves,while no significant differences exist between leaves and stems for inhibiting the secretion of tumor necrosis factorα(TNF-α)and NO.In conclusion,our results support using Keemun black tea stems as a novel source of anti-inflammatory compounds.
基金Thisworkwas financially supported by the joint funds of National Natural Science Foundation of China(U21A20232)the Natural Science Foundation of China(32002088,31870676,32072621)the National Key Research and Development Program of China(2018YFD1000601).
文摘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.
基金supported mainly by the Science Foundation for Anhui Province(KJ2017A126)to Xianchen Zhang the Opening Fund of State Key Lab of Tea Plants Biology and Utilization at Anhui Agricultural University(SKLTOF20170112)to Honghong Wu+1 种基金supported by the National Natural Science Foundation of China(11008389)the National Basic Research Program of China(11000206)to Xiaochun Wan
文摘Drought stress is one of the main factors limiting yield in tea plants. The plant cell's ability to preserve K^+homeostasis is an important strategy for coping with drought stress. Plasma membrane H^+-ATPase in the mesophyll cell is important for maintaining membrane potential to regulate K^+transmembrane transport. However, no research to date has investigated the possible relationship between plasma membrane H^+-ATPase and mesophyll K^+retention in tea plants under drought and subsequent rehydration conditions. In our experiment, drought stress inhibited plasma membrane H^+-ATPase activities and induced net H^+influx, leading to membrane potential depolarization and inducing a massive K^+efflux in tea plant mesophyll cells. Subsequent rehydration increased plasma membrane H^+-ATPase activity and induced net H^+efflux, leading to membrane potential hyperpolarization and thus lowering K^+loss. A first downregulated and then upregulated plasma membrane H^+-ATPase protein expression level was also observed under drought and subsequent rehydration treatment, a finding in agreement with the change of measured plasma membrane H^+-ATPase activities. Taken together, our results suggest that maintenance of mesophyll K^+in tea plants under drought and rehydration is associated with regulation of plasma membrane H^+-ATPase activity.
基金This work was supported by the Open Fund of State Key Laboratory of Tea Plant Biology and Utilization(SKLTOF20200122).
文摘Tea plants are sensitive to soil moisture deficit,with the level of soil water being a critical factor affecting their growth and quality.Arbuscular mycorrhizal fungi(AMF)can improve water and nutrient absorption,but it is not clear whether AMF can improve the photosynthetic characteristics of tea plants.A potted study was conducted to determine the effects of Claroideoglomus etunicatum on plant growth,leaf water status,pigment content,gas exchange,and chlorophyll fluorescence parameters in Camellia sinensis cv.Fuding Dabaicha under well-watered(WW)and drought stress(DS)conditions.Root mycorrhizal colonization and soil hyphal length were significantly reduced by the eightweek DS treatment.AMF inoculation displayed a significant increase in shoot and root biomass production.The relative water content,leaf water potential,nitrogen balance index,pigment content,maximum photometric effect(Fv/Fm,QY_max),and steady-state photometric effect Y(II)(QY_Lss)decreased dramatically,while the leaf water saturation deficit and steady-state non-photochemical fluorescence quenching(NPQ_Lss)generally increased under DS conditions.Mycorrhizal treatment induced significantly higher relative water content,leaf water potential,nitrogen balance index,pigment(chlorophyll,flavonoid,and anthocyanin)content,net photosynthesis rate,transpiration rate,stomatal conductance,intercellular CO_(2)concentration,QY_max,and QY_Lss;however,it resulted in a lower leaf water saturation deficit and NPQ_Lss under both WW and DS conditions,as compared with nonmycorrhizal plants.These results imply that AMF promoted tea plant growth and alleviated negative effects of DS by promoting gas exchange,regulating the water status of leaves,and regulating photosynthetic parameters.
基金This work was supported by grants from the National Natural Science Foundation of China(31770731 to Z.Z.)the National Key Research and Development Program of China(2018YFD1000601)+1 种基金the Base of Introducing Talents for Tea Plant Biology and Quality Chemistry(D20026)the Postdoctoral Science Foundation of China(2020M681636).
文摘Organic tea is more popular than conventional tea that originates from fertilized plants.Amino acids inorganic soils constitute a substantial pool nitrogen(N)available for plants.However,the amino-acid contents in soils of tea plantations and how tea plants take up these amino acids remain largely unknown.In this study,we show that the amino-acid content in the soil of an organic tea plantation is significantly higher than that of a conventional tea plantation.Glutamate,alanine,valine,and leucine were the most abundant amino acids in the soil of this tea plantation.When 15 N-glutamate was fed to tea plants,it was efficiently absorbed and significantly increased the contents of other amino acids in the roots.We cloned seven CsLHT genes encoding amino-acid transporters and found that the expression of CsLHT1,CsLHT2,and CsLHT6 in the roots significantly increased upon glutamate feeding.Moreover,the expression of CsLHT1 or CsLHT6 in a yeast amino-acid uptake-defective mutant,22Δ10α,enabled growth on media with amino acids constituting the sole N source.Amino-acid uptake assays indicated that CsLHT1 and CsLHT6 are H^(+)-dependent high-and low-affinity amino-acid transporters,respectively.We further demonstrated that CsLHT1 and CsLHT6 are highly expressed in the roots and are localized to the plasma membrane.Moreover,overexpression of CsLHT1 and CsLHT6 in Arabidopsis significantly improved the uptake of exogenously supplied 15 N-glutamate and 15 N-glutamine.Taken together,our findings are consistent with the involvement of CsLHT1 and CsLHT6 in amino-acid uptake from the soil,which is particularly important for tea plants grown inorganic tea plantations.
基金supported by the National Key Research and Development Program of China(2018YFD1000601)the National Natural Science Foundation of China(31171608)+2 种基金the Special Innovative Province Construction in Anhui Province(15czs08032)the Special Project for Central Guiding Science and Technology Innovation of Region in Anhui Province(2016080503B024)the Program for Changjiang Scholars and Innovative Research Team in University(IRT1101).
文摘Kunitz protease inhibitors(KPIs)are ubiquitous in plants and act as crucial compounds in defense responses against insect attack and pathogen infection.However,the influence of gene duplication on the postdivergence of the CsKPI genes involved in biotic stresses in tea plant is not well known.Here,we identified three CsKPI genes from tea plant(Camellia sinensis)and characterized their expression and evolutionary patterns among plant species.We found that CsKPI1,CsKPI2,and CsKPI3 diverged from their common ancestor 72.94 million years ago(MYA),and the tandem duplication of CsKPI2 and CsKPI3 occurred 26.78 MYA.An in vitro protein assay showed that the three CsKPI proteins were functional and inhibited the production of p-nitroanilide(PNA)from an artificial substrate.The three CsKPI-GFP fusion proteins localized to the cytoplasm.We showed that salicylic acid(SA)and transcripts of CsKPI2 and CsKPI3 significantly accumulated after infection with Glomerella cingulata.The application of exogenous SA stimulated the high expression of both CsKPI2 and CsKPI3 by activating cis-elements within their promoters.Under Ectropis oblique attack,CsKPI1 expression and jasmonic acid(JA)levels were more abundant in both insect-damaged leaf tissues and undamaged neighboring leaves.The application of jasmonic acid methyl ester elicited high expression levels of CsKPI1,suggesting that CsKPI1 accumulation requires JA production in tea plant.The overall findings suggest that the transcriptional divergence of KPI genes after duplication led to the specialized role of CsKPI1 in the physiological response to insect stress;the functional conservation between CsKPI2 and CsKPI3 confers resistance to pathogen infection in tea plant.
基金supported by grants from the National Natural Science Foundation of China(32072624,U20A2045)the National Key R&D Program of China(2022YFF1003103,2021YFD1601101)the Base of Introducing Talents for Tea Plant Biology and Quality Chemistry(D20026).
文摘Tea processed from albino/etiolated tea shoots is favored by consumers because of its high theanine accumulation.To explore why theanine accumulates highly in new shoots of albino/etiolated tea cultivars,we compared theanine content in shoots and roots of albino/etiolated and common green tea cultivars.Results suggested that high theanine accumulation in albino/etiolated tea shoots was likely not caused by higher theanine biosynthesis in roots.Further analyses suggested that CsAlaDC-catalyzed ethylamine biosynthesis and CsGOGAT1-catalyzed glutamate biosynthesis were more active,and CsGGT2-catalyzed theanine catabolism was weaker in new shoots of these albino/etiolated tea plant cultivars.Therefore,the high theanine accumulation in albino/etiolated shoots is probably contributed by the strong theanine biosynthesis and weak catabolism in new shoots.These findings provided more comprehensive insights into the high accumulation of theanine in new shoots of albino/etiolated tea cultivars,and the knowledge can be used in plant breeding for new cultivars with higher theanine accumulation.
基金supported by the Project of Major Science and Technology in Anhui Province(202003a06020021)the Project of Innovation and Training of Anhui Agricultural University(XJDC2021084)the National Natural Science Foundation of China(U20A2045).
文摘Self-incompatibility(SI)is a kind of plant fertilization obstacle,which can prevent the harmful effects of inbreeding decline,but it hinders the breeding of inbred lines.Tea plants have SI and long-term cross-pollination,which limits the progress of genetic research and variety improvement.However,the mechanism of SI in tea plants is still a mystery.Herein,microscopic observation showed that the pollen tube could pass through the base of style and enter the ovary cavity after 48 h of self-pollination at different flowering stages,and the SI intensity at bud stage and full bloom stage was lower than initial bloom stage.RNA-seq analysis showed that 1,463 and 1,409 differentially expressed genes(DEGs)were associated with low SI at bud stage and full bloom stage,respectively,and 507 DEGs were associated with SI at initial bloom stage.The results of qRT-PCR validation of 20 DEGs were consistent with the RNA-seq data.Furthermore,CsRNS,CsSRKL5 and CsSRKL8 specifically expressed in style,which may be related to the low SI at bud stage,and three CsACC genes may be related to the low SI at full bloom stage.The results provide useful information for understanding the mechanism of SI in tea plants.
基金the National Natural Science Foundation of China(32172626)the Anhui Provincial Natural Science Foundation(2208085MC72,1908085MC75)the Anhui University Collaborative Innovation Project(GXXT-2020-080).
文摘The WRKY gene family is most widely known as being the key plant transcription factor family involved in various stress responses and affecting plant growth and development.In this study,a total of 86 members of the CsWRKY genes were identified from the tea plant genome.Most of these genes contain several important Cis-regulatory elements in the promoter regions associated with multiple stress-responses.These genes were further classified into three groups,I,II,and III,each with 21,58,and 7 members,respectively.We showed evidence that tandem duplications,but not the whole genome duplication,are likely to drive the amplification of CsWRKY genes in tea plants.All the 86 CsWRKY genes showed differential expression patterns either in different tissues,or under exposure to diverse abiotic stresses such as drought,cold acclimation,and MeJA treatments.Additionally,the functional roles of two genes,CsWRKY29 and CsWRKY37,were examined under cold stress;and the silencing of these genes resulted in tea plant phenotypes susceptible to cold stress.Moreover,transgenic Arabidopsis lines overexpressing CsWRKY29 and CsWRKY37 genes showed higher survival rates and lower malondialdehyde levels under freezing treatment than the wild type plants.The core findings from this work provide valuable evolutionary pattern of WRKY gene family and underpinning the underlying regulatory roles of CsWRKY29 and CsWRKY37 from tea plants that conferred cold tolerance in transgenic Arabidopsis plants.
基金the National Natural Science Foundation of China(32002089)the Anhui Provincial Natural Science Foundation(201902a05020408)+1 种基金the National Key Research and Development Program of China(2018YFD1000601)the funding from Anhui Agricultural University and the State Key Laboratory of Tea Plant Biology and Utilization.
文摘Tea trichomes contribute significantly to tea flavors by providing diverse and specific flavor-determining metabolites,including catechins,caffeine,theanine,and volatiles.However,not much is known about the physiological functions of tea trichomes in tea plant adaptation to complex environments,nor the trichome development.Tea trichomes not only build up chemical defenses,but also act as the first physical barrier protecting herbivore attacks,reflecting high light and UV-B radiation,and preventing water loss.Moreover,transcriptome profiling on the tea trichomes compared with the trichome-removed leaves also showed that tea trichomes highly expressed numerous defense-related genes involved in protection from high light and UV-B radiation,cold stress,disease resistance signal transduction,anti-herbivore or anti-abiotic peptide biosynthesis,and other defense responses.Several pieces of experimental evidence supported the notes,highlighting the roles of tea trichomes in plant defenses against both abiotic and biotic stresses.The study provides fresh insights into the multiple protective functions of tea trichome for tea plant adaptation to harsh environments.The new understanding on tea trichomes could benefit the development of better breading strategy for new tea varieties with greater adaption and tolerance to changing environmental challenges.
基金supported by the National Natural Science Foundation of China(Grant Nos.32202542 and U20A2045)the Project of Major Science and Technology in Anhui Province(Grant No.202003a06020021)+2 种基金the Project of Science and Technology of Yunnan Province(Grant No.202102AE090038)Anhui Provincial Natural Science Foundation(Grant No.2108085QC121)the Natural Science Projects for Colleges and Universities in the Anhui Province(Grant No.KJ2021A0145)。
文摘Osmotic stress caused by low-temperature,drought and salinity was a prevalent abiotic stress in plant that severely inhibited plant development and agricultural yield,particularly in tea plant.Jasmonic acid(JA)is an important phytohormone involving in plant stress.However,underlying molecular mechanisms of JA modulated osmotic stress response remains unclear.In this study,high concentration of mannitol induced JA accumulation and increase of peroxidase activity in tea plant.Integrated transcriptome mined a JA signaling master,MYC2 transcription factor is shown as a hub regulator that induced by mannitol,expression of which positively correlated with JA biosynthetic genes(LOX and AOS)and peroxidase genes(PER).CsMYC2 was determined as a nuclei-localized transcription activator,furthermore,ProteinDNA interaction analysis indicated that CsMYC2 was positive regulator that activated the transcription of CsLOX7,CsAOS2,CsPER1 and CsPER3via bound with their promoters,respectively.Suppression of CsMYC2 expression resulted in a reduced JA content and peroxidase activity and osmotic stress tolerance of tea plant.Overexpression of CsMYC2 in Arabidopsis improved JA content,peroxidase activity and plants tolerance against mannitol stress.Together,we proposed a positive feedback loop mediated by CsMYC2,CsLOX7 and CsAOS2 which constituted to increase the tolerance of osmotic stress through fine-tuning the accumulation of JA levels and increase of POD activity in tea plant.
基金support from the National Natural Science Foundation of China(31800180)the Natural Science Foundation of Anhui Province(1908085MC75)+5 种基金the National Key Research and Development Program of China(2018YFD1000601)the Science and Technology Project of Anhui Province(13Z03012)the Special Innovative Province Construction in Anhui Province(15czs08032)the Changjiang Scholars and Innovative Research Team in University(IRT1101)the China Postdoctoral Science Foundation(No.2017M621992)the Postdoctoral Science Foundation of Anhui Province,China(No.2017B189).
文摘Tea is among the world’s most widely consumed non-alcoholic beverages and possesses enormous economic,health,and cultural values.It is produced from the cured leaves of tea plants,which are important evergreen crops globally cultivated in over 50 countries.Along with recent innovations and advances in biotechnologies,great progress in tea plant genomics and genetics has been achieved,which has facilitated our understanding of the molecular mechanisms of tea quality and the evolution of the tea plant genome.In this review,we briefly summarize the achievements of the past two decades,which primarily include diverse genome and transcriptome sequencing projects,gene discovery and regulation studies,investigation of the epigenetics and noncoding RNAs,origin and domestication,phylogenetics and germplasm utilization of tea plant as well as newly developed tools/platforms.We also present perspectives and possible challenges for future functional genomic studies that will contribute to the acceleration of breeding programs in tea plants.
基金supported by Hubei Science and Technology Plan Key Project(G2019ABA100)。
文摘Myriad evidence attests to the health-promoting benefits of tea drinking.While there are multiple factors of tea influencing the effective biological properties,tea polyphenols are the most significant and valuable components.The chemical characterization and physical characteristics of tea polyphenols have been comprehensively studied over the previous years.Still the emergence of new chemistry in tea,particularly the property of scavenging reactive carbonyl species(RCS)and the newly discovered flavoalkaloid compounds,has drawn increasing attention.In this review,we summarize recent findings of a new class of compounds in tea-flavonoid alkaloids(flavoalkaloids),which exist in fresh tea leaves and can be generated during the process of post-harvesting,and also postulate the formation mechanism of flavoalkaloids between catechins and theanine-derived Strecker aldehyde.Additionally,we detail the up-to-date research results of tea polyphenols regarding their ability to trap RCS and their in vivo aminated metabolites to suppress advanced glycation ends products(AGEs).We further raise questions to be addressed in the near future,including the synthetic pathways for the generation of flavoalkaloids and AGEs in fresh tea leaves before processing and the concentrations of tea polyphenols that affect their RCS scavenging capability due to their pro-oxidant nature.More intensive research is warranted to elucidate the mechanisms of action underlying the biological activity of flavoalkaloids and the pharmacological application of tea polyphenols in scavenging RCS and impeding detrimental AGEs.
基金the National Key Research and Development Program of China(2018YFD1000601)the Key Research and Development(R&D)Program of Anhui Province(18030701155)+1 种基金Funding from Anhui Agricultural University,and Funding from the State Key Laboratory of Tea Plant Biology and UtilizationThe Postgraduate Foundation of Anhui Agricultural University,Anhui Province,China(2020ysj-33).
文摘Under high light conditions or UV radiation,tea plant leaves produce more flavonols,which contribute to the bitter taste of tea;however,neither the flavonol biosynthesis pathways nor the regulation of their production are well understood.Intriguingly,tea leaf flavonols are enhanced by UV-B but reduced by shading treatment.CsFLS,CsUGT78A14,CsMYB12,and CsbZIP1 were upregulated by UV-B radiation and downregulated by shading.CsMYB12 and CsbZIP1 bound to the promoters of CsFLS and CsUGT78A14,respectively,and activated their expression individually.CsbZIP1 positively regulated CsMYB12 and interacted with CsMYB12,which specifically activated flavonol biosynthesis.Meanwhile,CsPIF3 and two MYB repressor genes,CsMYB4 and CsMYB7,displayed expression patterns opposite to that of CsMYB12.CsMYB4 and CsMYB7 bound to CsFLS and CsUGT78A14 and repressed their CsMYB12-activated expression.While CsbZIP1 and CsMYB12 regulated neither CsMYB4 nor CsMYB7,CsMYB12 interacted with CsbZIP1,CsMYB4,and CsMYB7,but CsbZIP1 did not physically interact with CsMYB4 or CsMYB7.Finally,CsPIF3 bound to and activated CsMYB7 under shading to repress flavonol biosynthesis.These combined results suggest that UV activation and shading repression of flavonol biosynthesis in tea leaves are coordinated through a complex network involving CsbZIP1 and CsPIF3 as positive MYB activators and negative MYB repressors,respectively.The study thus provides insight into the regulatory mechanism underlying the production of bitter-tasting flavonols in tea plants.
基金supported by Natural Science Foundation of China(32072633,32072634,31201335)earmarked fund for China Agriculture Research System(CARS-19)+1 种基金Anhui Key research and development plan(1804b06020367,202004b11020004)Young Elite Scientist Sponsorship Program by National CAST(2016QNRC001)。
文摘Roasting is a common manufacture technology for processing various teas.It is not only used in decreasing the water content of finished tea,but also improving the flavor of teas.In the present study,the roasted and non-roasted teas were compared by liquid-chromatography mass spectrometry and sensory evaluation.The roasted tea tasted less bitter and astringent.The content of main galloylated and simple catechins,caffeine and theobromine in roasted were significantly lower than non-roasted teas.Targeted taste-compounds metabolomics revealed that(-)-epigallocatechin gallate,kaempferol-glucose-rhamnose-glucose and(-)-epicatechin gallate were main contributors tightly correlated to astringent intensity.Flavonol glycosides including kaempferol-glucose,quercetin-glucose,kaempferol-glucose-rhamnose-glucose,and quercetin-glucose-rhamnose-glucose in roasted teas were also significantly less than non-roasted teas.To study the chemical changes during roasting,tea with a strong astringency was roasted under 80,100,120,140,and 160°C.With the increase of roasting temperature,the bitter and astringent intensity of tea was gradually decreased,but the main astringent compounds including(-)-epigallocatechin,(-)-epigallocatechin gallate and kaempferol/quercetin glycosides were irregularly varied with temperature.The Pearson correlation coefficient analysis suggested procyanidin B2,coumaroylquinic acids and gallotannins were tightly correlated to the astringent and bitter perceptions,while N-ethyl-2-pyrrolidonesubstituted flavan-3-ols were negatively correlated.
基金supported by the Science Foundation for Anhui Province,China(2022AH050919)the Anhui Provincial Key Research and Development,China(2022l07020019)+2 种基金the Anhui Province Science and Technology Major Project,China(202203a06020014)the National Key Research and Development Program of China(2021YFD1601103)the Anhui University Collaborative Innovation Project,China(GXXT-2020-080)。
文摘The growth and yield of tea plants are seriously limited by drought stress.Fatty acid desaturases(FADs)contribute to the mediation of membrane fluidity in response to different stresses,although the role ofω-3 FAD(Omega-3fatty acid desaturase)-mediated damage induced by drought stress in tea plants is poorly understood.In this study,drought stress significantly promoted the synthesis of C18:3(linolenic acid)and the expression level of CsFAD3.Yeast experiments further demonstrated that CsFAD3 can convert C18:2 to C18:3,and that the 35S:GFP-CsFAD3fusion protein was localized in the endoplasmic reticulum of Nicotiana benthamiana cells.CsFAD3-silenced tea leaves exhibited poor drought tolerance,with a lower F_(v)/F_(m)and a higher malondialdehyde(MDA)content than the control plants.However,transgenic 35S:CsFAD3 Arabidopsis plants showed the opposite phenotypes.In addition,the jasmonic acid(JA)content and the expression levels of CsLOX2,CsLOX4,CsAOS,CsAOC3 and CsOPR2 were significantly reduced in CsFAD3-silenced leaves under drought stress.However,no substantial difference in the salicylic acid(SA)content was detected under normal or drought conditions.An analysis of Atcoi1(JA receptor)or Atnpr1(SA receptor)mutant Arabidopsis plants in 35S:CsFAD3 backgrounds further revealed that knockout of Atcoi1impaired the drought-tolerant phenotypes of CsFAD3 overexpression lines.Therefore,this study demonstrated that CsFAD3 plays a crucial role in drought tolerance by mediating JA pathways.
基金This study was made possible by Naresuan University,Phisanulok,Thailand under the International Research University(IRU)program and Anhui Major Demonstration Project for Leading Talent Team on Tea Chemistry and Health,Anhui Department of Education,Hefei,China.
文摘Among six major types of tea(white,green,oolong,yellow,black,and dark teas)from Camellia sinensis,oolong tea,a semi-fermented tea,with its own unique aroma and taste,has become a popular consumption as indicated by the increasing production.Representing the characteristic flavonoids of oolong tea,theasinensins are dimeric flavan-3-ols.Many recent studies have indicated that oolong tea and theasinensins possess several health benefit properties.We consider it significant and necessary to have a comprehensive review in the recent advances of oolong tea.Therefore,the aim of the present review is to provide a new perspective on oolong tea and its characteristic phytochemicals,theasinensins associated with health benefits,molecular action pathway,and chemical mechanism of theasinensin formation from scientific evidences available on the literature.Furthermore,the chemical characterization of the oxidation products and the model oxidation system to the chemical changes of theasinensins are also discussed.
基金financially supported by National Natural Science Foundation of China(Grant Nos.31961133030,31870678,32022076)Science Fund for Distinguished Young Scientists of Anhui Province(Grant No.1908085J12).
文摘The carotenoid-derived volatileβ-ionone makes an important contribution to tea fragrance.Here,we qualitatively and quantitatively analysed 15 carotenoids in tea leaves of 13 cultivars by UHPLC-APCI-MS/MS.The 13 cultivars were divided into two groups by PCA(Principal Component Analysis)clustering analysis of their carotenoid content,and OPLS-DA(Orthogonal projections to latent structures)indicated that the levels ofβ-carotene(VIP=2.89)and lutein(VIP=2.30)were responsible for much of the variation between the two groups.Interestingly,theβ-carotene toβ-ionone conversion rates in Group 1 were higher than in Group 2,while theβ-carotene content was significantly lower in Group 1 than in Group 2.Theβ-ionone content was significantly higher in Group 1.Pearson Correlation Coefficient calculation between the transcription level of candidate genes(CsCCD1 and CsCCD4)and the accumulation ofβ-ionone indicated that CsCCD1 may involve in the formation ofβ-ionone in 13 cultivars.Prokaryotic expression and in vitro enzyme activity assays showed that‘Chuanhuang 1’had an amino acid mutation in carotenoid cleavage dioxygenases 1(CsCCD1)compared with‘Shuchazao’,resulting in a significantly higherβ-ionone content in‘Chuanhuang 1’.Sequence analysis showed that‘Chuanhuang 1’and‘Huangdan’had different CsCCD1 promoter sequences,leading to significantly higher CsCCD1 expression andβ-ionone accumulation in‘Chuanhuang 1’.These results indicated that the promoter and coding sequence diversity of CsCCD1 might contribute to the differential accumulation ofβ-ionone in different tea cultivars.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.32072623,31700611)。
文摘Flavonoids are critical secondary metabolites that determine the health benefits and flavor of tea,while chlorophylls are important contributors to the appearance of tea.However,transcription factors(TFs)that can integrate both chlorophyll biosynthesis and flavonoid accumulation in response to specific light signals are rarely identified.In this study,we report that the GOLDEN 2-LIKE TF pair,CsGLK1 and CsGLK2,orchestrate UV-B-induced responses in the chlorophyll biosynthesis and flavonoid accumulation of tea leaves.The absence of solar UV-B reduced the transcriptional expression of CsGLKs in the tea leaves and was highly correlated with a decrease in flavonoid levels(especially flavonol glycosides)and the expression of genes and TFs involved in chlorophyll biosynthesis and flavonoid accumulation.In vivo and in vitro molecular analyses showed that CsGLKs could be regulated by the UV-B signal mediator CsHY5,and could directly bind to the promoters of gene and TF involved in light-harvesting(CsLhcb),chlorophyll biosynthesis(CsCHLH,CsHEMA1,and CsPORA),and flavonoid accumulation(CsMYB12,CsFLSa,CsDFRa,and CsLARa),eventually leading to UV-B-induced responses in the chlorophylls and flavonoids of tea leaves.Furthermore,UV-B exposure increased the levels of total flavonoids,CsGLK1 protein,and expression of CsGLKs and target genes in the tea leaves.These results indicate that CsGLKs may modulate tea leaf characteristics by regulating chlorophyll biosynthesis and flavonoid accumulation in response to solar UV-B.As the first report on UV-B-induced changes in flavonoid and chlorophyll regulation mediated by CsGLKs,this study improves our understanding of the environmental regulations regarding tea quality and sheds new light on UV-B-induced flavonoid responses in higher plants.
