Identification of the lysine and histidine transporter family in Camellia sinensis and the characterizations in nitrogen utilization

In plants,the lysine and histidine transporter(LHT)family represent a class of proteins that mediate the uptake,translocation,and utilization of amino acids.The tea plant(Camellia sinensis)is a perennial evergreen with a relatively high level of amino acids.However,systematic identification and molecular characterization of the LHT gene family has rarely been reported in tea plants.In this study,22 CsLHTs were identified from the‘Shuchazao’genome and classified into two groups.The modeled three-dimensional structure and the conserved domains presented a high similarity among the LHTs proteins.Moreover,it was predicted that a few genes were conserved through the analysis of the physiochemical characters,structures and cis-elements in promoters.The expression patterns in tea plants revealed that CsLHT7 was mainly expressed in the roots,and CsLHT4 and CsLHT11 exhibited relatively high expression in both the roots and leaves.Moreover,the expression of all three genes could be induced by organic nitrogen.Additionally,heterogeneous expression of CsLHT4,CsLHT7 and CsLHT11 in Arabidopsis thaliana decreased the aerial parts biomass compared with that in WT plants while significantly increased the rosette biomass only for CsLHT11transgenic plants versus WT plants.Overall,our results provide fundamental information about CsLHTs and potential genes in N utilization for further analysis in tea plants.

Genetic analyses of ancient tea trees provide insights into the breeding history and dissemination of Chinese Assam tea(Camellia sinensis var.assamica)

Chinese Assam tea(Camellia sinensis var.assamica)is an important tea crop with a long history of cultivation in Yunnan,China.Despite its potential value as a genetic resource,its genetic diversity and domestication/breeding history remain unclear.To address this issue,we genotyped 469 ancient tea plant trees representing 26 C.sinensis var.assamica populations,plus two of its wild relatives(six and three populations of C.taliensis and C.crassicolumna,respectively)using 16 nuclear microsatellite loci.Results showed that Chinese Assam tea has a relatively high,but comparatively lower gene diversity(H_(S)=0.638)than the wild relative C.crassicolumna(H_S=0.658).Clustering in STRUCTURE indicated that Chinese Assam tea and its two wild relatives formed distinct genetic groups,with considerable interspecific introgression.The Chinese Assam tea accessions clustered into three gene pools,corresponding well with their geographic distribution.However,New Hybrids analysis indicated that 68.48%of ancient Chinese Assam tea plants from Xishuangbanna were genetic intermediates between the Puer and Lincang gene pools.In addition,10%of the ancient Chinese Assam tea individuals were found to be hybrids between Chinese Assam tea and C.taliensis.Our results suggest that Chinese Assam tea was domesticated separately in three gene pools(Puer,Lincang and Xishuangbanna)in the Mekong River valley and that the hybrids were subsequently selected during the domestication process.Although the domestication history of Chinese Assam tea in southwestern Yunnan remains complex,our results will help to identify valuable genetic resources that may be useful in future tea breeding programs.

Genome-Wide Identification of ABCC Gene Subfamily Members and Functional Analysis of CsABCC11 in Camellia sinensis

The ATP-binding cassette(ABC)transporter is a gene superfamily in plants.ATP-binding cassette subfamily C(ABCC)protein is a multidrug resistance-associated(MRP)transporter.They play various roles in plant growth,development,and secondary metabolite transport.However,there are few studies on ABCC transporters in tea plants.In this study,genome-wide association study(GWAS)analysis of epigallocatechin gallate(EGCG)content in 108 strains of Kingbird revealed that CsABCCs may be involved in EGCG transport.We identified 25 CsABCC genes at the genomic level of the tea plant,their phylogenetic tree,gene structure,targeted miRNA and other bioinformatics were analyzed.The expression patterns of CsABCCs in eight different tissues and abiotic stress indicate that they have potential roles in regulating the growth,development,and defense of tea plants.The correlation analysis revealed that the expression of the CsABCC11 gene was closely related to the EGCG content in tea buds of 108 strains of the Kingbird,and the subcellular localization experiments in tobacco showed that CsABCC11 protein was localized on the plasma membrane.The virus-induced gene silencing(VIGS)strategy in tea plants further verified that CsABCC11 was involved in EGCG accumulation.Our study laid a foundation for studying the biological function of CsABCC and provided a new candidate molecular marker gene for further EGCG-related variety breeding,which will be of great interest to breeders.

基于金观音(Camellia sinensis)单体型基因组CsUGT等位基因的鉴定及表达

【目的】植物的尿苷二磷酸糖基转移酶(UGT)是催化次生代谢物糖基化的关键酶,UGT基因主要参与植物逆境胁迫的响应。对CsUGT等位基因进行鉴定与表达分析,为其在茶树抗性及乌龙茶加工中香气形成的作用提供理论参考。【方法】基于金观音(Camellia sinensis‘Jinguanyin’)单体型基因组,利用生物信息学方法分析,并通过实时荧光定量PCR技术分析CsUGT基因在低温(4℃)、干旱(10%PEG-6000溶液)和激素(100μmol·L^(−1)MeJA溶液)处理下0、3、6、12和24 h的表达,以及CsUGT基因在金观音乌龙茶加工过程中鲜叶、萎凋、一摇、二摇、三摇和杀青前的表达。【结果】生物信息学分析结果表明,从金观音单体型基因组中鉴定出了142对等位基因,多数定位于叶绿体中,并基于进化树将这些基因分为5个亚家族。CsUGT等位基因的结构较保守,相同基因的亲本等位基因的结构相似。转录组数据分析表明,发现多数CsUGT等位基因具有组织表达特性。实时荧光定量PCR检测发现,在MeJA处理下,CsUGT002、CsUGT047和CsUGT091的表达量在6 h达到峰值;在低温和干旱处理下,部分CsUGT基因的表达量分别在3或24 h时达到峰值。此外,在金观音乌龙茶加工过程中,CsUGT115的表达量显著上调,部分CsUGT基因在三摇时的表达量达到峰值。【结论】CsUGT蛋白多数为酸性和亲水性蛋白,并定位于叶绿体中;CsUGT等位基因结构较保守具有组织表达特性,部分CsUGT基因参与调控茶树的逆境胁迫及乌龙茶加工工艺中摇青时的香气合成。

Analysis of NPK in Camellia sinensis, Gliricidia sepium, and Musa acuminata Biomasses for Preparation of an Organic Fertilizers Formula for Young Tea Plants (Musa acuminata) and Studying of Their Nutrient Release Capacity in the Biodegradation Process

This study investigates the nitrogen (N), phosphorous (P), and potassium (K) contents in raw biomasses of Camellia sinensis, Gliricidia sepium, and Musa acuminata. Therein, the highest N and P content was seen in Camellia sinensis 116.80 ± 0.08 mg and 66.00 ± 0.14 mg respectively. The highest K content (106.80 ± 0.04 mg) was observed in Musa acuminata. Next, all three types of plant materials were allowed to decompose in water for 3 weeks, and a sample from each was analyzed for NPK after the 1st, 2nd, and 3rd week during decomposition. A significant increase in the release of N, P, and K by the Camellia sinensis to water (P Musa acuminate were not significantly changed (P > 0.05) over time. The ratio for N:P:K was calculated for raw biomass samples and decomposed samples to find the best fitting N:P:K ratio to apply to young tea plants as organic fertilizers. In addition to that, the microbial insight of these organic compounds was analyzed by observing how microbial population increased with decomposition by the enumeration of the total microbial count. A considerable increment in total microbial count was observed up to 3.28 × 106, 1.21 × 1010, 2.18 × 108, and 6.49 × 107 CFU/ml for Camellia sinensis, Gliricidia sepium, Musa accuminata (leaves), and Musa accuminata (trunk) respectively. The presence of phosphate solubilizing bacteria (PSB) and nitrogen solubilizing bacteria (NSB) throughout the decomposition period was confirmed by their growth on NBRIP and a modified nutrient medium that was specifically designed for the identification of ammonifiers respectively. Prepared fertilizer samples were applied to young tea plants that were grown in the Mawanella area in Sri Lanka (7°15'12.42"N 80°26'47.62"E) and according to the results, it is clear that fertilizer mixture 1 (N:P:K, 10:5:10, tea dust + Gliricidia + banana trunk) and fertilizer mixture 2 (N:P:K, 10:5:10, tea dust + Gliricidia + banana leaves) has the potential to increase the growth of young tea plants.

中华绒螯蟹(Eriocheir sinensis)血细胞生成的初步研究

为了揭示失血和LPS刺激后中华绒螯蟹血细胞的生成及成熟过程,利用流式细胞技术将中华绒螯蟹造血组织细胞和血细胞按大小进行分类,利用EdU标记检测失血刺激后中华绒螯蟹造血组织细胞的增殖情况,分析失血和LPS刺激后中华绒螯蟹不同类型血细胞比例的变化.结果显示:中华绒螯蟹造血组织细胞分布于106~384μm^(2)之间,而血细胞分布在119~434μm^(2)之间,其中,透明细胞和小颗粒细胞主要分布在200~300μm^(2)之间,中颗粒和大颗粒细胞主要分布在300~400μm^(2)之间,随着血细胞颗粒性的增加,细胞逐渐增大.在失血刺激6、12和24 h时,中华绒螯蟹造血组织细胞增殖加速,说明失血刺激可以促进造血组织细胞增殖以加速新血细胞的生成.失血刺激2 h后透明细胞比例显著降低,至12 h时,各类细胞基本恢复至正常水平.LPS刺激1、3、6和9 h后,透明细胞比例呈现先降低后升高再降低的变化,而小、中和大颗粒细胞比例变化与透明细胞比例变化趋势相反,LPS刺激24 h和48 h后,透明细胞比例显著升高,大颗粒细胞比例显著降低.由此可知,失血和LPS刺激引起了中华绒螯蟹机体不同细胞的免疫反应,可能通过不同方式影响血细胞的生成、分化和成熟.

中华乌塘鳢(Bostrychus sinensis)白细胞介素8基因的克隆及免疫应答表达分析

由细菌等感染引起的疾病对中华乌塘鳢(Bostrychus sinensis)养殖业的可持续发展造成严重威胁。白细胞介素8(Interleukin-8,IL-8)在调节炎症反应和抗感染免疫方面扮演着重要的作用。利用PCR扩增和克隆测序获得了中华乌塘鳢IL-8(命名为BsIL-8)cDNA序列。BsIL-8 cDNA序列全长1244 bp,包含576 bp的5’端非编码区序列(5’-UTR),312 bp的开放阅读框序列(ORF)和356 bp的3’端非编码区序列(3’-UTR)。BsIL-8共编码103个氨基酸,包含1个由18个氨基酸组成的信号肽和1个由62个氨基酸组成的SCY结构域。其中,SCY结构域包含1个CXC基序(Cys^(30)-Arg^(31)-Cys^(32))以及4个保守的半胱氨酸残基(Cys^(30)、Cys^(32)、Cys^(57)和Cys^(73))。序列分析结果表明,BsIL-8与大弹涂鱼(Boleophthalmus pectinirostris)的IL-8序列相似性和一致性最高(分别为92.4%和86.4%)。基因组织表达分布结果显示,BsIL-8基因在主要组织器官中呈泛在性表达,头肾BsIL-8基础表达量最高,肝脏次之,外周血最低。Poly(I:C)免疫刺激后,BsIL-8在4个重要免疫器官(脾脏、肝脏、头肾和外周血)中的表达量均发生了显著的上调(分别在刺激后3、12、24和24 h时表达量达到最高,P<0.01)。副溶血弧菌(Vibrio parahaemolyticus)感染后,BsIL-8基因在脾脏和外周血中的表达量均显著上调(均在感染后12 h时表达量达到最高,P<0.01),而在肝脏和头肾中的表达量均显著下调(均在感染后12 h时表达量达到最低,P<0.01)。综上所述,BsIL-8基因参与了中华乌塘鳢抗感染免疫应答过程。

A constitutive serine protease inhibitor suppresses herbivore performance in tea(Camellia sinensis)

Protease inhibitors promote herbivore resistance in diverse plant species.Although many inducible protease inhibitors have been identified,there are limited reports available on the biological relevance and molecular basis of constitutive protease inhibitors in herbivore resistance.Here,we identified a serine protease inhibitor,CsSERPIN1,from the tea plant(Camellia sinensis).Expression of CsSERPIN1 was not strongly affected by the assessed biotic and abiotic stresses.In vitro and in vivo experiments showed that CsSERPIN1 strongly inhibited the activities of digestive protease activities of trypsin and chymotrypsin.Transient or heterologous expression of CsSERPIN1 significantly reduced herbivory by two destructive herbivores,the tea geometrid and fall armyworm,in tea and Arabidopsis plants,respectively.The expression of CsSERPIN1 in Arabidopsis did not negatively influence the growth of the plants under the measured parameters.Our findings suggest that CsSERPIN1 can inactivate gut digestive proteases and suppress the growth and development of herbivores,making it a promising candidate for pest prevention in agriculture.

Molecular cloning and functional analysis of two calcium associated cuticular protein genes in Neocaridina denticulata sinensis

The body surface of crustaceans is covered with a sturdy shell.The growth and development of crustaceans are realized through molting.Neocaridina denticulata sinensis is a suitable candidate for crustacean scientific research.Two calcium-associated cuticular protein genes,named NdCAP-1 and NdCAP-2,were obtained from N.denticulata sinensis.Molecular docking simulated the binding effect of both proteins and calcium ions.Semi-quantitative reverse transcription PCR results show that NdCAP-1 is expressed in D_(2-4) stage,NdCAP-2 expressed in D_(2-4) and A-B stages,and both were significantly expressed in the cephalothorax cuticle and pereiopods.Then,it was revealed that NdCAP-1 and NdCAP-2 are regulated by NdEcR-mediated 20 E signaling pathways.Knockdown of NdCAP-1 and NdCAP-2 was observed to cause surface defects.The recombinant proteins(rNdCAP-1 and rNdCAP-2),obtained by prokaryotic expression,had calcium-binding and chitin-binding ability,inhibited formation of calcium carbonate precipitate.These results show that calcium-associated cuticular proteins play important roles in cuticle formation and calcification.

Ankylosing spondylitis coexisting with Clonorchis sinensis infection: A case report

BACKGROUND Ankylosing spondylitis(AS)is a chronic immune-mediated inflammatory disease.The prevailing theory links AS onset to infections in susceptible individuals.Furthermore,infections may impair the immune responses.Numerous studies have investigated links between AS and various infections-bacterial,viral,fungal,and other microorganism infections.However,limited attention has been given to the association between AS and Clonorchis sinensis(C.sinensis)infection.CASE SUMMARY A 27-year-old male with a 10-yr history of AS presented to our hospital with inflammatory lower back pain as the primary manifestation.Ten years ago,the patient had achieved a stable condition after treatment with biological agents.However,he experienced a recurrence of lumbosacral pain with an unexplained cause 10 d before hospital admission.A lumbosacral magnetic resonance imaging(MRI)scan revealed bone marrow edema in the left sacroiliac joint,and laboratory indicators were elevated.Moreover,the presence of C.sinensis eggs was detected in the stool.The patient was prescribed praziquantel,resulting in the disap-pearance of C.sinensis eggs in subsequent routine stool tests and relief from lumbosacral pain.A follow-up MRI scan performed after 4 months revealed a reduction in bone marrow edema around the left sacroiliac joint.CONCLUSION C.sinensis infections could potentially trigger the exacerbation of AS.Clinicians should pay attention to investigating the presence of infections.INTRODUCTION Ankylosing spondylitis(AS)is a chronic inflammatory and rheumatic disease resulting from an imbalance between innate and acquired immune responses[1].While it can affect any part of the spine,its primary symptoms are persistent back pain and stiffness in the lower back and pelvis.The prevalence of AS per 10000 individuals is 23.8 in Europe,31.9 in North America,16.7 in Asia,10.2 in Latin America,and 7.4 in Africa[2].Infections commonly occur in the first 3 months and may act as potential triggers for the first symptoms of AS,often manifesting as gastrointestinal,urinary tract,and respiratory infections of microbiological origin[3,4].Clonorchis sinensis(C.sinensis)infection is a severe parasitic disease affecting millions globally,especially prevalent in China,South Korea,the Far East of Russia,and Vietnam,with an estimated 15 million cases[5].Transmission occurs through the consumption of undercooked freshwater fish containing metacercariae.Adult C.sinensis parasites then establish themselves within the human hepatobiliary system[6].C.sinensis infection triggers the activation of sphingosine 1-phosphate receptor 2,leading to the injury and fibrosis of the hepatobiliary[7].Recent research in a rat model found that C.sinensis infection increases the risk of hepatocellular carcinoma by stimulating hepatic progenitor cell proliferation[8].Complications of C.sinensis infection include cholestasis,cholangitis,biliary system fibrosis,and in severe cases,the development of cholangiocarcinoma[9].Consequently,the primary preventive measure is to abstain from consuming raw or undercooked freshwater fish.Praziquantel is the recommended and effective treatment for this infection[10].While there is existing literature on the coexistence of AS and parasitic infections,there is limited research specifically addressing the simultaneous presence of AS and C.sinensis infection.This case report details a rare scenario of AS coexisting with C.sinensis infection,underscoring the potential impact of C.sinensis infection on AS disease activity.

Natural variation of main biochemical components,morphological and yield traits among a panel of 87 tea [Camellia sinensis(L.) O. Kuntze] cultivars

Many attentions have been previously focused to identify the multiple biochemical components related to tea quality and health benefits,however, the natural variation of biochemical components present in tea germplasm has not been adequately evaluated. In this study, the main biochemical components, leaf morphological and yield characteristics were evaluated for four rounds of tea leaves in a panel of 87 elite tea cultivars suitable for black, green, or oolong tea. Significant variations were observed among the tea cultivars, as well as seasonal differences in the levels of the free amino acid(FAA), caffeine(CAF), tea polyphenols(TP), water extract(WE) and TP to FAA ratio(TP/FAA). Results showed that the average levels of FAA showed a seasonal change, with the highest level of 4.0% in the 1st spring tea in the cultivars suitable for green tea and the lowest of 3.2% in summer tea in the cultivars suitable for black tea. The average CAF content was highest 3.2% in the cultivars suitable for oolong tea in the 1st spring and the lowest 2.5% in the cultivars suitable for green tea in summer. Limited seasonal and varietal variations were noticed in the average levels of WE among the three categories of tea. In addition, significant natural variation of the morphological characteristics, bud length varying from 2.5 cm to 8.7 cm, bud density from 190.3 buds · m-2to 1 730.3 buds · m-2, mature leaves biomass from 128.4 kg · hm-2to 2 888.4 kg · hm-2, and yield component traits of 100 buds(one bud with two leaves) dry weight from 3.7 g to37.7 g, tea yield/round from 444.6 kg · hm-2to 905.3 kg · hm-2, were observed. The aim of our evaluation was not only to identify the advantages of seasonal and clonal variations but also to provide a new viewpoint for their further application. Representative accessions were selected from the germplasm to promote the establishment of an inherent biochemical constituent expressing the quality of black, green, and oolong tea. The findings might be utilized to establish early selection criteria to enhance the tea breeding and production program.

Differential metabolites and their transcriptional regulation in seven major tea cultivars (Camellia sinensis) in China

Various genetic and biochemical characteristics exist in tea plant cultivars,and they largely determine production suitability and tea quality.Here,we performed transcriptomic and metabolomic analyses of young shoots of seven tea cultivars and identified major regulatory transcription factors(TFs)for the characteristic metabolites in different cultivars based on weighted gene co-expression network analysis(WGCNA).Phenotypically,we found that‘Tieguanyin’(TGY)and‘Fujian Shuixian’(FJSX),which are suitable for oolong tea,had higher catechin contents.The metabolites of‘Jinxuan’(JX)were more prominent,especially the contents of phenolic acids,flavonoids,terpenes,and tannins,which were higher than those of the other six cultivars.Moreover,‘Fudingdabai’(FDDB),which is suitable for white tea,was rich in amino acids,linolenic acid,and saccharides.At the molecular level,hydroxycinnamoyl CoA quinate hydroxycinnamoyl transferase(HCT)(CsTGY12G0001876,and CsTGY06G0003042)led to the accumulation of chlorogenic acid in TGY.The main reason for the higher l-ascorbic acid content in FJSX was the high expression levels of L-galactono-1,4-lactone hydrogenase(GalLDH)(CsTGY13G0000389)and Myo-inositol oxygenase(MIOX)(CsTGY14G0001769,and CsTGY14G0001770),which were regulated by WRKY(CsTGY11G0001197).Furthermore,FDDB,‘Longjing 43’(LJ43),‘Shuchazao’(SCZ)and‘Baihaozao’(BHZ)had higher free fatty acid contents,among which MYB(CsTGY14G0002344)may be a hub gene for the regulation of palmitoleic acid accumulation.More importantly,we found that the shoots of TGY were green with purple,mainly due to the accumulation of anthocyanins and the downregulation of the Mg-protoporphyrin IX nonomethyl ester cyclase(MPEC)(CsTGY10G0001989)gene that affects chlorophyll synthesis.These results will provide a theoretical reference for tea cultivar breeding and suitability.

The high-resolution three-dimensional(3D)chromatin map of the tea plant(Camellia sinensis)

Dear Editor,Tea plant(Camellia sinensis(L.)O.Kuntze)is one of the world’s most important non-alcoholic beverages,with great economic,health,and cultural value.Recently,several genomes of C.sinensis var.assamica(CSA)(Yunkang 10),C.sinensis var.sinensis(CSS)(Shuchazao,Biyun,Longjing 43,Tieguanyin,Huangdan),and ancient tea plant(DASZ)have been deciphered[1-3].

Research advances in aluminum tolerance and accumulation in tea plant(Camellia sinensis)

Tea plant(Camellia sinensis)is widely planted on acidic soils where aluminum(Al)toxicity is considered as a primary factor limiting plant growth.Unlike most plant species,tea plant is Al tolerant and accumulates high levels of Al.Understanding the mechanisms underlying Al tolerance and accumulation in tea plant may contribute to the improvement of tea plant cultivation and development of Al-tolerant crops.In this review,we summarize recent advances in the uptake,transport and accumulation of Al in tea plant and the genetic and environmental factors that affect these processes.We further highlight recent studies of Al in tea plant based on omics approaches,including transcriptomics,proteomics,metabolomics,ionomics and microbiomics.We present perspectives for future research that will be helpful to decipher the mechanisms underlying Al tolerance and accumulation in tea plant.

Genome-wide characterization and identification of candidate CsRAV genes involved in JA pathway responses to cold stress in tea plant(Camellia sinensis)

The APETALA2/ethylene response factor(AP2/ERF)transcription factor(TF)superfamily plays an important regulatory role in the signal transduction of plant responses to various biotic and abiotic stresses,including low temperature.RAV is a subfamily of the AP2/ERF TF family,and its members contain B3 DNA binding and AP2 DNA binding domains.RAV gene family members have been studied in many species,but little is known about their function in tea plants(Camellia sinensis).In this study,seven RAV genes were identified from the tea plant genome database and named CsRAV1-7.Based on phylogenetic analysis,the CsRAV genes were classified into three groups,with genes in the same subgroup exhibiting similar structures and conserved motifs.Out of the seven genes,CsRAV7 was the most distinct and contained a large number of motifs and the longest coding region.Moreover,analysis of cis-acting elements indicated that CsRAVs are likely responsive to both abiotic stress and phytohormones.In addition,quantitative RT-PCR analysis revealed that most CsRAV genes were differentially expressed under cold stress and exogenous MeJA application as both individual and combined treatments.Only CsRAV7 was induced in all six different treatments,suggesting that it may play a key role in JA-mediated cold stress responses in tea plants.

Cytological and transcriptional insights of late-acting selfincompatibility in tea plants(Camellia sinensis)

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.

Complete genome sequence of a plant growth-promoting endophytic bacterium V4 isolated from tea(Camellia sinensis)leaf

V4 is a Gram-negative,plant growth promoting endophytic bacterium that promotes the growth of tea plants.The appearance of V4 is rod shaped,with average dimensions of 1.34−1.5×0.32−0.39μm and flagellum at both ends.The complete genome contains one circular chromosome and two plasmids.It is 4,697,109 bp in size,and contains 4,189 protein-coding genes,four gene islands and two prophages.Taxonomic classification suggested that V4 was a strain of Erwinia aphidicola.It was possible to find genes involved in plant growth promotion traits present in the genome of V4.Meanwhile,V4 was consistent with plant growth-promoting endophytic bacteria containing key synthetic genes associated with IAA synthesis,and P-solubilization,siderophores.V4 has siderophore biosynthesis genes compared with plant pathogenic bacteria showing stronger survival ability and the ability to interaction with the host plant.In addition,V4 endophytic bacteria possess a higher copy number of genes for flagellar assembly,bacterial chemotaxis and P-pilus assembly indicating stronger colonization and communication ability with host plants compared with five other bacteria in comparative genomic analysis.Analysis of the V4 endophytic bacterium complete genome sequence provides novel insights into the endophytic bacteria-host plant relationship,and suggests many candidate genes for post-genomic experiments.

Mineral Elements in Different Varieties of Camellia sinensis

To understand the mineral elements in different varieties of tea （ Camellia sinensis）, 17 mineral elements in eight tea varieties including Yunnan Dayezhong, No. 43 Longjing and No. 6 Zaobaijian, were measured. The results showed that nine elements, such as P, K, Ba, Mn, Cu, were significantly different among varieties, others did not. Black tea varieties usually contain high contents of Cu and K. As a conclusion, mineral elements should be extensively considered in breeding tea varieties.

茶Camellia sinensis L.对铝的吸收与累积研究

对广东省几个大型茶场中不同土壤背景值的 8个茶园 ,进行了土壤及茶树各部位的铝含量调查研究。地处我国南方的广东省茶园 ,其土壤中铝的含量都较高 ,全量在 6 0 0 0 0～ 15 0 0 0 0mg·kg- 1 之间 ,但有效态铝含量相对较低 ,仅为 30～ 40 0mg·kg- 1 之间 ,而且与土壤中全铝量大小无关 ,而与土壤酸碱度 (pH)呈极显著的负相关 ,相关系数r=- 0 9732。铝在茶树各部位含量大小依次为落叶 >成熟叶 >根 >枝条 >幼叶。茶树凋落叶铝含量最高 ,平均达 (112 71± 332 )mg·kg- 1 ,而用于加工成饮用茶的幼叶 (一芽两叶 )部分最低 ,平均只有 (6 39±2 32 )mg·kg- 1 ,同时期的相应茶场的茶叶制成品中 ,铝的含量亦接近这一水平 ,为 (978± 2 32 )mg·kg- 1 。土壤中的有机质、酸碱度 (pH)、总钾和有效钾、全铝和有效铝都对茶树各部位铝的累积产生较大影响 ,但只有土壤pH值对铝在茶树体内向幼叶部分的转移和累积影响达显著程度 ,幼叶铝含量与土壤pH之间的相关系数r =0 772 ,呈显著正相关 (P <0 0 5 )。

茶(Camellia sinensis L.)对铜的吸收与累积

对广东省5个大型茶场中不同土壤背景值的8个茶园进行了土壤及茶(CamelliasinensisL.)树各部位的铜含量分析调查。地处我国南方的广东省茶园,土壤中铜含量在2.39～53.05mg kg之间。有效态铜含量相对较低,仅在0.45～3.17mg kg之间。茶树中各部位铜含量大小依次为枝条>幼叶>根>成熟叶。茶树枝条和幼叶铜含量较高,平均分别达14.5和14.3mg kg,远高于成熟叶铜含量水平(9.7mg kg)。而同时期相应茶场的茶叶制成品铜含量则较幼叶(一芽两叶)铜的含量高。土壤中的总钾、有效磷和总铜等都对茶树各部位铜的累积产生较大影响,但只有土壤有效磷含量对铜在茶树体内向枝条部分的转移和累积影响达显著程度,枝条铜含量与土壤有效磷之间的相关系数r=-0.74,呈显著负相关(P<0.05)。