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The increasing incidence of anthracnose disease in tea plant caused by Colletotrichum has become an important global concern. It is the cause of withered leaves of the tea plant, leading to a considerable decrease in the economic yield of tea, and thereby threatening the sustainable development of tea industries. In this study, Colletotrichum infected tea leaves were collected from three separate regions: Zhouning, Longyan, and Ningde in Fujian province, China. The pathogen was isolated from the leaves and identified based on morphology following Koch’s postulates and DNA sequencing of the nuclear rDNA internal transcribed spacer (ITS) region, beta-tubulin 2 (β-Tub2), the large subunit of the nuclear ribosomal RNA gene (LSU), Glutamine synthetase (GS), and an oligonucleotide primer (CgInt). A total of six strains were identified with different cultural, morphological, and molecular characteristics. Furthermore, multi-locus phylogenetic analysis showed the six strains that belong to C.fructicola. Finally, a preliminary screening of nine chemical fungicides to inhibit the strain N by toxicity test identified 40% prochloraz at 0.1 μg mL–1 as the most effective method. The phylogenetic tree analysis revealed a close relationship between the identified strains, and the strains were classified based on cultural, morphological, and molecular characteristics. The findings of this study add to our understanding of C.fructicola, which will aid in the development of preventive measures, the improvement of tea quality, and the assurance of safe production.

Pyrethroids (PYs) have been widely used to control pests and prevent diseases in tea gardens. However, with the increasingly stringent pesticide testing standards in the import and export trade of tea, there is an urgent need for methods to detect trace amounts of PYs in tea. In this study, a covalent organic framework (COF) material TpBD with excellent thermal/chemical stability, high porosity, and a large specific surface area was prepared by a room-temperature solution-suspension approach (SSA). TpBD-coated solid phase microextraction (SPME) fibers were fabricated by coating the material on etched stainless-steel fibers by a simple physical coating method. The fibers were used in combination with gas chromatography-tandem mass spectrometry (GC-MS/MS) to establish a highly sensitive method for the detection of PYs. The enrichment factors of this method for cyfluthrin, cypermethrin, flucythrinate, fenvalerate, and deltamethrin were 702-2687. The method showed low LODs (0.1-0.5 ng/L), wide linear ranges (0.2-800 ng/L), good linearities (correlation coefficients (R)≥0.9991) and acceptable repeatabilities (RSD≤11.0%, n=3). Green tea and oolong tea samples were analyzed using the developed method, and trace levels of the five PYs were successfully detected. The recoveries of the spiked PYs in the real green tea and oolong tea samples were in the range of 80.2%-109.5%. Experimental results showed that the established analytical method is suitable for the determination of PY pesticides in tea. Furthermore, the TpBD material was successfully prepared by the SSA method, demonstrating that the method has good universality and excellent potential for the simple synthesis of other COF materials.

Genome-wide identification and characterization of nuclear factor-Y family in tea plants, and their expression profiles and putative targets provide the basis for further elucidation of their biological functions. The nuclear factor-Y (NF-Y) transcription factors (TFs) are crucial regulators of plant growth and physiology. However, the NF-Y TFs in tea plant (Camellia sinensis) have not yet been elucidated, and its biological functions, especially the putative target genes within the genome range, are still unclear. In this study, we identified 35 CsNF-Y encoding genes in the tea plant genome, including 10 CsNF-YAs, 15 CsNF-YBs and 10 CsNF-YCs. Their conserved domains and motifs, phylogeny, duplication event, gene structure, and promoter were subsequently analyzed. Tissue expression analysis revealed that CsNF-Ys exhibited three distinct expression patterns in eight tea tree tissues, among which CsNF-YAs were moderately expressed. Drought and abscisic acid (ABA) treatment indicated that CsNF-YAs may have a greater impact than other subunit members. Furthermore, through the genome-wide investigation of the presence of the CCAAT box, we found that CsNF-Ys may participate in the development of tea plants by regulating target genes of multiple physiological pathways, including photosynthesis, chlorophyll metabolism, fatty acid biosynthesis, and amino acid metabolism pathways. Our findings will contribute to the functional analysis of NF-Y genes in woody plants and the cultivation of high-quality tea plant cultivars.

Plant-specific WUSCHEL-related homeobox (WOX) transcription factors regulate plant developmental processes, especially those involved in embryogenesis. However, studies on WOX family genes in tea plants do not exist. In this study, a total of eighteen CsWOX members were identified in the tea plant genome and divided into three clades based on the phylogenetic results; they included ancient, intermediate and modern clades, which reflected the evolutionary history of WOX families. Furthermore, ancient clade members had more gene structural variations than other clade members and had unique conserved motifs. The expression profiles of eight tissues showed that six CsWOX genes were highly expressed in at least four tissues, while other genes were expressed at a very low level or not expressed. Moreover, numerous cold-, drought-, ethylene-, methyl jasmonate (MeJA)-, abscisic acid (ABA)-, and gibberellic acid (GA)-responsive cis-elements were observed in the CsWOX promoter regions, and we subsequently investigated their expression patterns under these treatments. Notably, the ancient clade members may play more active roles than members of the other clades in environmental adaptation in tea plants. Our work provides precise information on CsWOX family genes that will benefit the further understanding of their functional roles in tea plants.

Tea plants (Camellia sinensis) are commercially cultivated in >60 countries, and their fresh leaves are processed into tea, which is the most widely consumed beverage in the world. Although several chromosome-level tea plant genomes have been published, they collapsed the two haplotypes and ignored a large number of allelic variations that may underlie important biological functions in this species. Here, we present a phased chromosome-scale assembly for an elite oolong tea cultivar, “Huangdan”, that is well known for its high levels of aroma. Based on the two sets of haplotype genome data, we identified numerous genetic variations and a substantial proportion of allelic imbalance related to important traits, including aroma- and stress-related alleles. Comparative genomics revealed extensive structural variations as well as expansion of some gene families, such as terpene synthases (TPSs), that likely contribute to the high-aroma characteristics of the backbone parent, underlying the molecular basis for the biosynthesis of aroma-related chemicals in oolong tea. Our results uncovered the genetic basis of special features of this oolong tea cultivar, providing fundamental genomic resources to study evolution and domestication for the economically important tea crop.

Plants have evolved regulatory mechanisms at multiple levels to regulate gene expression in order to improve their cold adaptability. However, limited information is available regarding the stress response at the chromatin and translational levels. Here, we characterize the chromatin accessibility, transcriptional, and translational landscapes of tea plants in vivo under chilling stress for the first time. Chilling stress significantly affected both the transcription and translation levels as well as the translation efficiency of tea plants. A total of 3010 genes that underwent rapid and independent translation under chilling stress were observed, and they were significantly enriched in the photosynthesis-antenna protein and phenylpropanoid biosynthesis pathways. A set of genes that were significantly responsive to cold at the transcription and translation levels, including four (+)-neomenthol dehydrogenases (MNDs) and two (E)-nerolidol synthases (NESs) arranged in tandem on the chromosomes, were also found. We detected potential upstream open reading frames (uORFs) on 3082 genes and found that tea plants may inhibit the overall expression of genes by enhancing the translation of uORFs under chilling stress. In addition, we identified distal transposase hypersensitive sites (THSs) and proximal THSs and constructed a transcriptional regulatory network for tea plants under chilling stress. We also identified 13 high-confidence transcription factors (TFs) that may play a crucial role in cold regulation. These results provide valuable information regarding the potential transcriptional regulatory network in plants and help to clarify how plants exhibit flexible responses to chilling stress.

Wuyi rock tea is a typical and famous oolong tea in China and roasting is an important manufacturing procedure for its flavor formation. This work aimed to explore the effect of roasting on non-volatiles and volatiles of 12 Wuyi rock tea samples at three roasting levels (low, moderate and sufficient), made from four tea cultivars (Shuixian, Qizhong, Dahongpao, Rougui). Results show that different roasting had not caused significant difference on contents of soluble solids, total polyphenols, flavonoids, soluble sugar, thearubigins and theabrownins, while it slightly regulated caffeine, proteins and theaflavins, and remarkably reduced catechins and free amino acids. The ratio of polyphenol content/amino acid content, a negative-correlated indicator of fresh and brisk taste, significantly increased with the increase of roasting degree. High-level roasting not only decreased the fresh and brisk taste of the tea infusion, but also reduced the amount of bioactive ingredients including catechins and theanine. A total of 315 volatiles were detected and analyzed with OPLS-DA and HCA methods, in which 99 volatiles were found with variable importance in the projection (VIP) values greater than 1.00. Tea samples at different roasting degrees were successfully separated by this model of roasting-level discrimination. ‘Naphthalene, 1,2,3,4-tetrahydro-1,6,8-trimethyl-’, ‘1,1,5-trimethyl-1,2-dihydronaphthalene’, ‘p-Xylene’, ‘alpha.-methyl-.alpha.-[4-methyl-3-pentenyl]oxiranemethanol’, ‘hydrazinecarboxylic acid, phenylmethyl ester’, and ‘3-buten-2-one, 4-(2,6,6-trimethyl-2-cyclohexen-1-yl)-’ might be key characteristic markers for the roasting process of Wuyi rock tea.

Tea varieties with specific colours have often been studied by researchers. However, previous studies on the albinism of tea plants have mostly been based on plants with different genetic backgrounds or focused on common components in albino tea leaves, such as amino acids, flavones, and carotenoids. In this study, we conducted widely targeted metabolic and transcriptomic analyses between a wildtype tea genotype (Shuixian, LS) and its albino mutant (Huangjinshuixian, HS). At the molecular level, alteration of gene expression levels in the MEP pathway may have reduced the production of chlorophyll and carotenoids in HS, which could be the main cause of the phenotypic changes in HS. At the metabolite level, a large number of metabolites related to light protection that significantly accumulated in HS, including flavones, anthocyanins, flavonols, flavanones, vitamins and their derivatives, polyphenols, phenolamides. This result, combined with an enzyme activity experiment, suggested that the absence of photosynthetic pigments made the albino tea leaves of HS more vulnerable to UV stress, even under normal light conditions. In addition, except for the common amino acids, we also identified numerous nitrogen-containing compounds, including nucleotides and their derivates, amino acid derivatives, glycerophospholipids, and phenolamides, which implied that significant accumulation of NH4+ in albino tea leaves could not only promote amino acid synthesis but could also activate other specialized metabolic pathways related to nitrogen metabolism. In conclusion, our results provide new information to guide further studies of the extensive metabolic reprogramming events caused by albinism in tea plants.

The WRKY transcription factors (TFs) family is one of the largest TF families in plants and plays a central role in diverse regulation and multiple stress responses. However, the systematical analysis of the WRKY gene family in tea plant (Camellia sinensis) based on genomic data has been lacking. The primary objective of this study was to set a systematic analysis of the WRKY gene family based on genomic data in tea plant and analyze their expression profiles under various abiotic stresses. We searched the tea plant genome using the consensus model of the WRKY domain (PF03106) and then used these search results to identify all the WRKY family members by SMART and the CDD program. Analyze their phylogeny, classification, structure, conserved motifs, Cis-elements, interactors and expression profiles. 56 putative WRKY genes were identified from the tea plant genome and divided into three main groups (I-III) and five subgroups (IIa-IIe) according to the WRKY domains and the zinc-finger structure. The gene structure and conserved motifs of the CsWRKY genes were also characterized and were consistent with the classification results. Annotation analysis showed that 34 CsWRKY genes may be involved in stress responses. Promoter analysis implied that CsWRKY genes, except for CsWRKY55, possessed at least one abiotic stress response cis-element. Expression profiles of CsWRKY genes in different tissues were analyzed with RNA-seq data. The results showed that 56 CsWRKY genes had differential expression in their transcript abundance. The expression profiles also showed that many identified CsWRKY genes were possibly involved in the response to cold, drought, salt, or ABA treatment. Tea plant genome contains at least 56 WRKY genes. These results provide useful information for further exploring the function and regulatory mechanism of CsWRKY genes in the growth, development, and adaption to abiotic stresses in tea plant.

A facile and rapid strategy for preparation of covalent organic framework (COF) coated fibers at ambient temperature is urgently needed for solid-phase microextraction (SPME) technology. In this work, an in situ room-temperature rapid growth strategy was developed to high-efficiently fabricate imine-linked COF (TPB-DVA) coated fibers in as little as 30 min at room temperature, and the thickness of the coating reached 9 μm. The prepared TPB-DVA coated fiber offer high thermal and chemical stability, and outstanding service lifetime. Moreover, we generalize this strategy to other two imine-linked COF (TPB-DMTP and TFPB-TAPB) coated fibers and the fibers were fabricated at room temperature for 3 h and 12 h, respectively, which demonstrate the applicability of this strategy. Subsequently, a SPME-GC-MS/MS analytical method was developed for trace pyrethroids (PYs) detection, which exhibited high enhancement factors (EFs, 2700–13195), wide linear range (0.08–800 ng L−1), low limits of detection (LODs, 0.02–0.20 ng L−1), and good repeatability (RSD ≤ 8.5%, n = 6). Furthermore, the developed analytical method was applied to tea samples and trace PYs (1.31–4.32 ng L−1) were found with satisfactory recovery (80.2–119.8%). The above results demonstrated that the feasibility of the developed strategy for the facile and rapid fabrication of imine-linked COF coated fibers.

The capacity of intersection affects the maximum capacity of road to a certain extent. The traffic capacity of the intersection can be improved to some extent by optimizing and adjusting the parameters of the signal timing model. Taking the cross-type intersection at the intersection of Minzhu South Road and Fengshou Road in Jiaozuo City as the research background, this study optimizes the signal timing design for the current intersection, optimizes the signal timing design by using Webster algorithm, and conducts simulation by using traffic simulation software VISSIM. The results showed that the average delay at the intersection was reduced by nearly seven seconds.

In this paper, the improved numerical method is used to time the traffic lights at intersections. The traditional numerical solution method cannot make the setting of phase difference the most reasonable, and the actual distance of each intersection cannot completely meet the ideal distance, resulting in a lot of loss of green time. Therefore, this method still needs to be improved. Although the survey data in this paper are obtained through field investigation, they are still not universal. More accurate data come from multiple surveys and integration.

In recent years, my country’s road infrastructure has been vigorously constructed, urban road network density has increased, and road intersections have also been formed. There are more and more T-shaped intersections. Such intersections often have the characteristics of serious traffic intertwining and difficult traffic organization. Opposite the intersection of Zhan Qian Road and Min Zhu Zhong Road is the railway station. A large number of pedestrians have to pass through the intersection at rush hour or when the train arrives at the station. This road has a lot of people and a large number of non-motorized vehicles. The signal lights at the intersection are not perfect, and the traffic demand is large. In this paper, based on the current signal timing plan and the current status of the crosswalk at the intersection, based on the actual current data survey and service level analysis, the optimization design of the intersection signal timing plan and the crosswalk width optimization are completed. The results showed that the average delay at the intersection was improved by nearly 21 seconds, and the crosswalk lengths at the east entrance, west entrance and north entrance were optimized to 2.5m, 2.4m and 2.6m, respectively. Improved road capacity and reduced vehicle delays.

C-repeat binding factors (CBFs) are key signaling genes that can be rapidly induced by cold and bind to the C-repeat/dehydration-responsive motif (CRT/DRE) in the promoter region of the downstream cold-responsive (COR) genes, which play a vital role in the plant response to low temperature. However, the CBF family in tea plants has not yet been elucidated, and the possible target genes regulated by this family under low temperature are still unclear. In this study, we identified five CsCBF family genes in the tea plant genome and analyzed their phylogenetic tree, conserved domains and motifs, and cis-elements. These results indicate that CsCBF3 may be unique in the CsCBF family. This is further supported by our findings from the low-temperature treatment: all the CsCBF genes except CsCBF3 were significantly induced after treatment at 4 &deg, C. The expression profiles of eight tea plant tissues showed that CsCBFs were mainly expressed in winter mature leaves, roots and fruits. Furthermore, 685 potential target genes were identified by transcriptome data and CRT/DRE element information. These target genes play a functional role under the low temperatures of winter through multiple pathways, including carbohydrate metabolism, lipid metabolism, cell wall modification, circadian rhythm, calcium signaling, transcriptional cascade, and hormone signaling pathways. Our findings will further the understanding of the stress regulatory network of CsCBFs in tea plants.

Based on the analysis of the evolution of the production layout of jasmine tea since the founding of new China, this paper further explores the heterogeneity of the comparative advantage in the main producing areas of jasmine tea from four aspects: comparative advantage index of efficiency, comparative advantage index of scale, comprehensive comparative advantage index and comparative advantage index of development. The research shows that except for Fujian, the traditional producing areas of jasmine tea have lost their comparative advantages, such as Zhejiang and Guangdong. Although the emerging producing areas, led by Guangxi, have absolute advantages in terms of comprehensive comparative advantages, but have no advantages in terms of the development advantage index. Therefore, it is necessary for all parties to focus on the key technical issues in order to achieve the sustainable and healthy development of the jasmine tea industry. Based on the above research results, it is proposed initiative and economic new normal opportunities should be seized to improve the international competitiveness and influence of China’s jasmine tea industry under the background of “One Belt And One Road”. To improve effective supply, promote tea consumption to promote economic growth and other suggestions.

In the context of deepening supply-side reform in China, based on the national tea planting area and yield data from 1993 to 2018, combined with GIS technology and spatial center of gravity statistical models, this paper analyzes the characteristics of China’s tea development and change in 25 years in detail, and comprehensively analyses the driving mechanism of the changes. The following conclusions are drawn: China’s tea production space has changed significantly, and the country’s tea planting area and output have been on the rise, but the changes are inconsistent; The continuous westward shift of the center of tea production in China is caused by the joint influence of nature, economy and society, among which resource endowment and policy support are the most important driving forces.

Blue light extensively regulates multiple physiological processes and secondary metabolism of plants. Although blue light quantity (fluence rate) is important for plant life, few studies have focused on the effects of different blue light intensity on plant secondary metabolism regulation, including tea plants. Here, we performed transcriptomic and metabolomic analyses of young tea shoots (one bud and two leaves) under three levels of supplemental blue light, including low-intensity blue light (LBL, 50 &mu, mol m&ndash, 2 s&ndash, 1), medium-intensity blue light (MBL, 100 &mu, 1), and high-intensity blue light (HBL, 200 &mu, 1). The total number of differentially expressed genes (DEGs) in LBL, MBL and HBL was 1, 7 and 1097, respectively, indicating that high-intensity blue light comprehensively affects the transcription of tea plants. These DEGs were primarily annotated to the pathways of photosynthesis, lipid metabolism and flavonoid synthesis. In addition, the most abundant transcription factor (TF) families in DEGs were bHLH and MYB, which have been shown to be widely involved in the regulation of plant flavonoids. The significantly changed metabolites that we detected contained 15 lipids and 6 flavonoid components. Further weighted gene co-expression network analysis (WGCNA) indicated that CsMYB (TEA001045) may be a hub gene for the regulation of lipid and flavonoid metabolism by blue light. Our results may help to establish a foundation for future research investigating the regulation of woody plants by blue light.

Albino tea mutants with specific shoot colors (white or yellow) have received increasing attention from researchers due to their unique phenotypes, beneficial metabolites, and special flavor. In this study, novel natural yellow leaf mutants of the same genetic background of &ldquo, Rougui&rdquo, were obtained, and the transcriptome and metabolite profiles of the yellow leaf mutant (YR) and original green cultivar (GR) were investigated. A total of 130 significantly changed metabolites (SCMs) and 55 differentially expressed genes (DEGs) were identified in YR compared to GR. The leaf coloration of YR was primarily affected by pigment metabolism including of chlorophyll, carotenoids, and flavonoids, and the co-expression of three heat shock proteins (HSPs) and four heat shock transcription factors (HSFs) may also regulate leaf coloration by affecting chloroplast biogenesis. Of the 130 SCMs, 103 showed clearly increased abundance in YR, especially nucleotides and amino acids and their derivatives and flavonoids, suggesting that YR may be an ideal albino tea germplasm for planting and breeding. Our results may help to characterize the leaf coloration and metabolic mechanism of albino tea germplasm.

The SQUAMOSA promoter binding protein (SBP)-box gene family is a plant-specific transcription factor family. This family plays a crucial role in plant growth and development. In this study, 20 SBP-box genes were identified in the tea plant genome and classified into six groups. The genes in each group shared similar exon-intron structures and motif positions. Expression pattern analyses in five different tissues demonstrated that expression in the buds and leaves was higher than that in other tissues. The cis-elements and expression patterns of the CsSBP genes suggested that the CsSBP genes play active roles in abiotic stress responses, these responses may depend on the abscisic acid (ABA), gibberellic acid (GA), and methyl jasmonate (MeJA) signaling pathways. Our work provides a comprehensive understanding of the CsSBP family and will aid in genetically improving tea plants.

The SQUAMOSA promoter binding protein (SBP)-box gene family is a plant-specific transcription factor family. This family plays a crucial role in plant growth and development. In this study, 20 SBP-box genes were identified in the tea plant genome and classified into six groups. The genes in each group shared similar exon-intron structures and motif positions. Expression pattern analyses in five different tissues demonstrated that expression in the buds and leaves was higher than that in other tissues. The cis-elements and expression patterns of the CsSBP genes suggested that the CsSBP genes play active roles in abiotic stress responses; these responses may depend on the abscisic acid (ABA), gibberellic acid (GA), and methyl jasmonate (MeJA) signaling pathways. Our work provides a comprehensive understanding of the CsSBP family and will aid in genetically improving tea plants.