Camellia Sinensis Research Articles

LncRNA81246 regulates resistance against tea leaf spot by interrupting the miR164d-mediated degradation of NAC1.

Non-coding RNAs play crucial roles in plant responses to viral stresses. However, their molecular mechanisms in tea leaf spot responses remain unclear. In this study, using Camellia sinensis, we identified lncRNA81246 as a long non-coding RNA that localizes to both the nucleus and cytoplasm. It functions as a competitive endogenous RNA, thereby disrupting CsNAC1 (encoding NAC domain-containing protein 1) degradation mediated by miR164d. Silencing lncRNA81246 increased the resistance of tea plants to presistanceathogens, whereas transient lncRNA81246-overexpression plants showed decreased resistance to pathogens. Co-expression assays in Nicotiana benthamiana revealed that lncRNA81246 affects the miR164d-CsNAC1 regulatory module. Transient miR164d-overexpression and silencing assays demonstrated its positive regulation of tea plant resistance. Specifically, silencing its target, CsNAC1,enhanced disease resistance, whereas transient overexpression reduced plant resistance. Yeast one-hybrid, dual-luciferase, and RT-qPCR assay results suggested that CsNAC1 alters the expression of CsEXLB1, whereas AsODN and tobacco transient overexpression assays showed that CsEXLB1 negatively regulated tea plant resistance. Thus, our research demonstrated that lncRNA81246 acts as a mediator to interfere with the miR164d-CsNAC1 regulatory module involved in the disease resistance of tea plants.

Effects of intercropping with legume forage on the rhizosphere microbial community structure of tea plants.

Intercropping in agriculture is crucial for addressing challenges in intensive tea farming. Forage legumes reduce fertilizer dependence and significantly boost productivity. Currently, intercropping with legumes enhances the environmental conditions of tea plantations and improves tea quality. However, the comprehension of the rhizosphere's impact on the associated microbes and the community structure of tea plants is still somewhat constrained. Hence, four distinct planting methodologies were examined: Monoculture cultivation of Tieguanyin tea plants (MT), Laredo forage soybean (Glycine max Linn.) without partitioning in conjunction with tea (IT), intercropping with tea using plastic partitions (PPIT), and intercropping with tea facilitated by net partitions (NPIT). An absolute quantitative analysis of soil phospholipid fatty acids, labeled with the rhizosphere microbial characteristics of tea plants, was conducted through multi-ion reaction monitoring (MRM). The bacterial and fungal communities were anticipated utilizing the FAPROTAX and FUNG databases, respectively. Gas chromatography was employed to ascertain greenhouse gas emissions across diverse root interaction cultivation systems. The rhizospheric influence culminated in a 44.6% increase in total phospholipid fatty acids (PLFAs) and a remarkable 100.9% escalation in the ratio of unsaturated to saturated fatty acids. This rhizospheric enhancement has significantly potentiated the ecological functionalities within the bacterial community, including xylanolysis, ureolysis, nitrogen respiration, nitrogen fixation, nitrite respiration, nitrite ammonification, and nitrate reduction. Mycorrhizomonas, encompassing both ectomycorrhizal and arbuscular forms, has notably colonized the rhizosphere. The interspecific mutualistic interactions within the rhizosphere have resulted in a significant enhancement of plant growth-promoting bacteria, including allorhizobium, bradyrhizobium, rhizobium, burkholderia, gluconacetobacter, and gluconobacter, while concurrently reducing the prevalence of pathogenic microorganisms such as xanthomonas, ralstonia, fusarium, and opportunistic fungi responsible for white and soft rot. The intercropping system showed lower total greenhouse gas emissions than monocultured tea plants, particularly reducing soil CO2 emissions due to complex interspecific rhizosphere interactions. This tea/legume intercropping approach promotes a sustainable ecosystem, enhancing microbial biomass and vitality, which helps suppress rhizospheric pathogens. These findings are instrumental in enhancing our comprehension of the pivotal practical implications of rhizosphere intercropping, thereby optimizing the structure of rhizosphere communities and alleviating the impact of greenhouse gases within croplands.

Identification of Pseudopestalotiopsis ampullacea as a new pathogen causing tea gray blight in India and its management strategies

Gray blight is a serious threat to the tea [Camellia sinensis (L.) O. Kuntze] production in major tea cultivating countries including India. The disease is caused by Pestalotiopsis-like species. In this study, five isolates of Pseudopestalotiopsis species isolated from symptomatic tea leaf samples in North Bengal, India were investigated. Based on the multi-locus phylogenetic analysis using concatenated sequences of three (ITS, tef-1 alpha, and tub-2) loci, cultural and micromorphological characters, and host association, the fungal isolates were identified as Pseudopestalotiopsis ampullacea F. Liu & L. Cai. The morphological analysis also revealed that the fungal isolates were evidently differentiated from other Pseudopestalotiopsis species. To date, P. ampullacea has not been reported on tea plants in India. Among the five isolates studied, isolate NKT0P03 was randomly selected for pathogenicity tests and its sensitivity to fungicides and microbial antagonists. In pathogenicity test, the isolate showed weak to high virulence reactions on 25 different tea cultivars. The pathogen showed an avirulent reaction on the cultivar TV11. In order to identify an effective management strategy against this new pathogen, synthetic fungicides and microbial biocontrol agents were evaluated in the laboratory. Results revealed that carbendazim + mancozeb, hexaconazole, propiconazole, and valextra were effective fungicides with an 85.1% to 89.8% range of inhibitory activity against P. ampullacea NKT0P03. Among microbial agents, Trichoderma harzianum, T. reesei, T. hamatum, Bacillus subtilis, and Microbacterium barkeri were efficient bioagents against P. ampullacea NKT0P03 with antagonistic activity ranging between 66.6% and 84.2%. Thus, these fungicides and microbial bioagents can be recommended as effective agents for the management of P. ampullacea causing tea gray blight after their field evaluations.

Impact of spreading time on flavor quality in Duyun Maojian summer green tea

Duyun Maojian (DYMJ) is a prestigious green tea in China. The summer tea has higher tea polyphenols contents than spring tea, which reduces the green tea flavor quality and limits utilization of summer tea. Spreading is an important technology for optimizing tea quality, but its effect on DYMJ summer green tea is still unclear. In this study, we employed transcriptomics and volatile metabolomics to investigate the effect of spreading times (0, 1, 2, 3, 4, 5, 6, 7 h) on the flavor quality of DYMJ summer green tea. Sensory evaluation showed that the best taste was obtained at 4 h of spreading time. All indexes of main taste compounds reached peaking within 3–5 h (except for catechin). At 3–5 h of spreading time, important aromatic compounds with distinct floral and fruity flavors (such as phenylethanol, geraniol and cis-jasmone) were highest. Correlation analysis showed that there was a significant relationship between the main taste components and the tea aroma. In addition, transcriptomic analysis suggests that pathways related to hormone signaling and flavonoid biosynthesis in tea plants may play a key role in tea spreading. This study provides a theoretical framework for the processing of DYMJ summer green tea.

Highly Conductive Multifunctional Iron‐Incorporated Polythiophene Nanocomposite: A Nanocatalyst for Nitrobenzene Reduction in Aqueous Medium and an Efficient Room Temperature Methanol Gas Sensor

ABSTRACTThis study reports the synthesis and application of a polythiophene–iron oxide (PTh‐Fe0‐Fe2O3) nanocomposite as a highly effective catalyst for the selective reduction of nitro aromatics in an aqueous environment. The nanocomposite was synthesized using in situ chemical polymerization, with Fe0‐Fe2O3 nanoparticles created from ferric chloride solution using Camellia sinensis leaf extract as a reducing and stabilizing agent at room temperature. Characterization techniques, including XRD, FTIR, SEM–EDX, TEM, XPS, and UV–Vis spectroscopy, confirmed the successful integration of Fe0‐Fe2O3 into the polythiophene matrix. The nanocomposite demonstrated higher electrical conductivity compared to PTh alone, ranging from 20 S/cm at 313 K to 53 S/cm at 373 K. Magnetic studies indicated a saturation magnetization of 23.1 emu/g, lower than the 42.6 emu/g of Fe0‐Fe2O3 nanoparticles, attributed to the non‐magnetic nature of PTh. Under optimal conditions (4‐nitrobenzaldehyde [1 mmol], catalyst [0.04 g], and water [5 mL] in air), the catalyst achieved a 94% yield in the reduction of nitrobenzenes within 7 h, demonstrating broad applicability and retaining significant catalytic activity over six cycles. Furthermore, the PTh‐ Fe0‐Fe2O3 nanocomposite exhibited notable methanol gas sensing capabilities, with a sensitivity of 52.6 at 200‐ppm methanol. The sensor exhibited a response time of 60 s and a recovery time of 80 s, attributed to its n‐type semiconductor characteristics and abundant oxidative‐reductive sites. Computational studies supported the methanol sensing mechanism, highlighting significant O… S interactions and stable non‐covalent interactions between methanol and the nanocomposite. This study is the first to introduce a novel magnetic nanocatalyst for the cost‐effective and eco‐friendly reduction of nitroarenes, while also demonstrating its applicability in gas sensing. The research highlights an environmentally sustainable synthesis process and enhanced material properties, showcasing the nanocatalyst's potential for diverse applications.

Multiomics correlation analysis on the mechanism of flavor substance formation during the processing of "Huanong 53″ black tea

A comprehensive investigation was conducted using targeted metabolomics, transcriptomics, and GC-MS techniques to study the dynamic changes in volatile and non-volatile metabolites, as well as gene transcription levels, in five processing stages of 'Huanong 53′ black tea (Camellia sinensis). A total of 2062 metabolites were identified, with flavonoids (428) and amino acids and their derivatives (194) being the main categories. The types and contents of flavor characteristic components of black tea changed most significantly during the withering and fermentation stages. Key elements of tea aroma composition, including linalool, benzeneacetaldehyde, and geraniol were found to correspond significantly with specific transcripts annotated as linalool synthase, aromatic aminotransferase, and geraniol diphosphate synthase, respectively. Throughout processing, a decrease in catechins and concomitant increase in oxidized catechin dimers, such as theaflavin (TF), was positively correlated with down-regulated flavonoid pathway gene expression and up-regulated expression of putative TF biosynthetic genes, including laccases, polyphenol oxidase, and a wide range of peroxidases. This study provides a comprehensive perspective on the changes in metabolites during black tea processing, and contributes to the research on improving black tea quality and the suitability of tea varieties for processing.

Characteristics and Functions of Rhizosphere Bacterial Communities of Camelli sinensis cv. Shifocui with Cold Resistance Characteristics in Anhui Province, China.

The rhizosphere bacterial community of plants has a crucial effect on healthy plant growth, and each rhizosphere has a specific microbial community. Camellia sinensis cv. Shifocui (C. sinensis cv. Shifocui) is a tea plant distributed in the Dabie Mountains of Anhui Province. It has the characteristics of high yield, good quality, strong cold resistance, and a high amino acid content. This study was the first to use 16S rRNA high-throughput sequencing technology and bioinformatics methods to explore the characteristics and functions of the rhizosphere bacterial community of the cold-tolerant tea tree C. sinensis cv. Shifocui, providing an important basis for the development and utilization of rhizosphere microbial resources. The dominant phylum in the rhizosphere microbes of the C. sinensis cv. Shifocui rhizosphere microorganisms were Proteobacteria, Chloroflexi, Acidobacteriota, and Actinobacteria. Network analysis showed significant positive and negative correlations among the rhizosphere bacterial groups of C. sinensis cv. Shifocui, among which Candidatus _ Xiphinematobacter, Acidobacteriale, Bradyrhizobium, Subgroup _ 2, Candidatus_Udaeobacter, Gemmataceae, and Gaiellales were notable nodes in theinteraction networks. Functional prediction of FAPROTAX indicated that C. sinensis cv. Shifocui was rich in chemoheterotrophic, cellulose hydrolysis, and oxidative heterotrophic conditions, indicating that the dominant bacterial flora was enriched in its rhizosphere microbes and played an important role in plant growth and development. These results lay a foundation for exploring the mechanism of interaction between C. sinensis cv. Shifocui and rhizosphere microorganisms and provide a research basis for the development and utilization of tea plant microbial resources.

CsWRKY12 interacts with CsVQ4L to promote the accumulation of galloylated catechins in tender leaves of tea plants.

Galloylated catechins in tea leaves, primarily epigallocatechin-3-gallate (EGCG) and epicatechin gallate (ECG), possess prominent biological activities. It is well established that EGCG and ECG are abundantly present in tender leaves but are less prevalent in mature leaves. However, the fundamental regulatory mechanisms underlying this distribution remain unknown. In this study, we integrated transcriptome data and catechin component levels in tea leaves from six leaf positions using weighted gene co-expression network analysis. This analysis revealed a positive correlation between variations in CsWRKY12 expression and EGCG and ECG levels. Further investigation using yeast one-hybrid and dual-luciferase assays, as well as electrophoretic mobility shift assay, demonstrated that CsWRKY12 activated the transcription of CsSCPL4 and CsSCPL5, which encode enzymes responsible for galloylated catechins biosynthesis, by directly binding to W-box elements in their promoters. Overexpression of CsWRKY12 in tea leaves promoted the expression of CsSCPL4 and CsSCPL5, leading to an increase in EGCG and ECG content. Moreover, we found that a VQ motif-containing protein, CsVQ4L, interacted with CsWRKY12 and facilitated its transcriptional function by regulating the expression of CsSCPL4 and CsSCPL5. Collectively, our findings suggest that the interaction between CsWRKY12 and CsVQ4L contributes to the accumulation of galloylated catechins in tender leaves of tea plants.

Effect of bioactive compounds in processed Camellia sinensis tea on the intestinal barrier

The human intestinal tract plays a pivotal role in safeguarding the body against noxious substances and microbial pathogens by functioning as a barrier. This barrier function is achieved through the combined action of physical, chemical, microbial, and immune components.Tea (Camellia sinensis) is the most widely consumed beverage in the world. Tea is consumed and appreciated in a multitude of regions across the globe. Tea can be classified into various categories, including green, white, yellow, oolong, black, and dark teas, based on the specific processing methods employed. In recent times, there has been a notable surge in scientific investigation into the various types of tea. The recent surge in research on tea can be attributed to the plethora of bioactive compounds it contains, including polyphenols, polysaccharides, pigments, and theanine. The processing of different teas affects the active ingredients to varying degrees, resulting in a range of chemical reactions and the formation of different types and quantities of ingredients. The bioactive compounds present in tea are of great importance for the maintenance of the integrity of the intestinal barrier, operating through a variety of mechanisms. This literature review synthesizes scientific studies on the impact of the primary bioactive compounds and different processing methods of tea on the intestinal barrier function. This review places particular emphasis on the exploration of the barrier repair and regulatory effects of these compounds, including the mitigation of damage to different barriers following intestinal diseases. Specifically, the active ingredients in tea can alleviate damage to physical barriers and also alleviate damage to chemical barriers by regulating barrier protein expression. At the same time, they can also maintain the stability of immune and biological barriers by regulating the expression of inflammatory factors and the metabolism of intestinal flora. This investigation can establish a strong theoretical foundation for the future development of innovative tea products.

Real-Time In Situ Tracking of the Penetration and Uptake Behavior of Nano-pesticides in Tea Plants Using Surface-Enhanced Raman Spectroscopy.

In situ monitoring of the uptake and transportation process of nano-pesticides during crop growth remains challenging thus far. In this report, the different three sizes of surface-enhanced Raman spectroscopy probes of nano-pesticides loaded with ferbam and acetamiprid are representative non-systemic or systemic pesticides, respectively. The probes were verified to have strong signals of the Raman spectrum enhancement effect. They were further applied on the leaves and roots of tea plants. Within 5 h, the nano-pesticides of 50 nm and 100 nm except 150 nm probes could rapidly penetrate young tea leaves to a depth of about 150-290 μm. Whereas none of the probes were observed to penetrate mature leaves and roots of tea plants. The result showed that the penetration rate depended on the size of the nano-pesticides and the structure or maturity of the plant tissue rather than the loaded pesticides. The penetration rate of small-sized nano-pesticides in young tea leaves is the fastest.

Effects of potassium on tea quality are associated with the accumulation of anthocyanins in tea plant

Effects of potassium on tea quality are associated with the accumulation of anthocyanins in tea plant

CsCBF2 contributes to cold repression of chlorophyll and carotenoid biosynthesis in albino Camellia sinensis cv. Baiye 1.

C-repeat binding factors (CBFs) play a pivotal role in regulating cold response in higher plants. Camellia sinensis cv. Baiye 1, a representative albino tea cultivar, has been identified as temperature-sensitive based on long-term observations by tea farmers. However, it remains unclear whether CsCBFs are involved in temperature-mediated albinism and seasonal greening in 'Baiye 1', and the mechanisms by which CBFs regulate cold responses in albino leaves are unknown. In this study, we demonstrate that CsCBF2 suppresses the seasonal greening of albino leaves by inhibiting chlorophyll and carotenoid biosynthesis under cold stress. In tea plantations, the accumulation of chlorophylls and carotenoids in the albino shoots of 'Baiye 1' is closely correlated with the effective accumulated temperature during its seasonal greening process. Weighted Gene Co-expression Network Analysis revealed negative associations between CsCBF expression and chlorophylls, carotenoids, as well as their biosynthetic genes REVEILLE 1 (CsRVE1) and Zeaxanthin epoxidase 1 (CsZEP1) under temperature fluctuations during seasonal greening. Cold-induced upregulation of CsCBF2 expression and decreased chlorophylls and carotenoids under controlled climate conditions. Transient suppression of CsCBF2 by antisense oligodeoxynucleotide elevated expressions of target genes, and increased chlorophylls and carotenoids. CBF-binding cis-elements were identified in CsRVE1, Protochlorophyllide oxidoreductase A (CsPORA), and CsZEP1 promoters. Luciferase assays suggested CsCBF2 binding to the CRT/DRE cis-elements and repressing expression of CsRVE1, CsPORA, and CsZEP1. These findings highlight CsCBF2 as a key transcriptional repressor involved in the seasonal greening of albino 'Baiye 1' under cold stress, by modulating cold responses and inhibiting genes associated with chlorophyll and carotenoid biosynthesis.

CsWRKY29, a key transcription factor in tea plant for freezing tolerance, ABA sensitivity, and sugar metabolism

Tea plants (Camellia sinensis L.) are prone to spring frosts, leading to substantial economic damage. WRKY transcription factors are key in plant abiotic stress responses, yet the role of CsWRKY29 in freezing tolerance is unclear. In this study, quantitative real-time PCR (qRT-PCR) and transient green fluorescent protein assay revealed that CsWRKY29 localizes to the nucleus and its expression is induced by cold and abscisic acid (ABA). CsWRKY29 overexpression in Arabidopsis enhanced freezing tolerance, reduced electrolyte leakage, increased soluble sugars, and boosted superoxide dismutase activity, with upregulated COR genes. These lines also showed heightened ABA and glucose sensitivity. Cold treatment of CsWRKY29-overexpressing lines upregulated AtABI5, AtHXK1, and AtSUS4 compared to wild type, and yeast one-hybrid assays confirmed CsWRKY29 binding to the W-box in the CsABI5 promoter. Furthermore, the application of virus-induced gene silencing (VIGS) technology to reduce CsWRKY29 expression in tea plants revealed a significant decrease in the transcript levels of CsCBFs, CsABI5, CsHXK1, and CsSUS4 in the silenced plants. In summary, our findings indicate that CsWRKY29 may serve as a critical transcription factor that contributes to freezing tolerance, ABA responsiveness, and sugar metabolism within tea plants.

The effect of a poly-herbal plant extract on the adhesion of Streptococcus mutans to tooth enamel

BackgroundDental caries, also known as tooth decay or cavity formation, is one of the world’s most widespread dental conditions. It is a plaque-related infection caused mainly by Streptococcus mutans. People have relied on several plant species to treat oral infections; Heteropyxis natalensis, for example, has been used to treat toothache and gum infections.MethodsIn this study, the antimicrobial and anti-adherence properties of H. natalensis and Camellia sinensis, as well as tea tree and peppermint essential oils were investigated on tooth enamel.ResultsThe bacterial load of S. mutans was reduced by approximately two orders of a magnitude after 48 h, with a lesser extent on the commensal bacteria, Lactobacillus paracasei. Scanning electron micrographs of enamel blocks showed a reduction in the attachment and chain formation of S. mutans and degraded cell morphology. Lastly, the combination and each component individually, showed low to no cellular toxicity when tested on human macrophages.ConclusionsThis is the first report of this polyherbal regarding its selectivity and potential prevention of dental caries.

Gibberellin promotes theanine synthesis by relieving the inhibition of CsWRKY71 on CsTSI in tea plant (Camellia sinensis)

Abstract Theanine is a crucial indicator of tea quality, its significance is closely tied to the economic value of tea. There were many reports on the regulation mechanism of theanine synthesis and accumulation, but the mechanism of gibberellin regulates theanine synthesis in tea plants is poorly understood. Previous studies have shown that the content of theanine experiences significant changed in the growth stages of tea shoots, displayed a strong correlation with gibberellin. This study confirmed that gibberellin significantly promoted the expression of the major gene of theanine synthesis, known as CsTSI. Additionally, the study identified CsWRKY71, a transcription factor mediated the regulation of gibberellin on theanine synthesis in tea plants. CsWRKY71 was localized in the nucleus and had a typical WRKY domain. It was a member of class IIC sub- and its expression was significantly suppressed following exogenous GA3 treatment. Further assay such as EMSA, dual luciferase and asODN interfering demonstrated that CsWRKY71 significantly interacted with the promoter of CsTSI, which inhibited theanine synthesis by binding to the cis-acting element (C/T)TGAC(T/C) of CsTSI promoter. Overall, the addition of exogenous gibberellin alleviated the inhibition of CsTSI by down-regulating the expression of CsWRKY71, ultimately facilitated the rapid biosynthesis of theanine. This study elucidated the molecular mechanism of CsWRKY71 mediated gibberellin regulation of theanine synthesis in tea plant. The findings not only enhance our understanding of the regulatory processes involved in theanine synthesis in tea plants, but also provide important references for maintaining the characteristics of high theanine in tea plant.

Genome-Wide Analysis of the Multidrug and Toxic Compound Extrusion Gene Family in the Tea Plant

The multidrug and toxic compound extrusion (MATE) family is the latest class of novel secondary transporters discovered in plants. However, there is currently no comprehensive analysis of the MATE gene family in the tea plant. In this study, 68 CsMATE genes were identified from the tea plant genome using bioinformatic methods. In general, we analyzed the evolutionary relationships, intron–exon structure, distribution in chromosomes, conserved domains, and gene expression patterns in different tissues and stresses of the CsMATE gene family. The 68 CsMATEs were phylogenetically divided into four major clusters (Class I to Class IV). The CsMATE genes within the same class exhibit similar structural features, while displaying certain distinctions across different classes. Evolutionary analysis indicated that the CsMATE gene family expanded mainly through gene duplication events, in addition to proximal duplication. Through the analysis of cis-acting elements, it was found that CsMATE genes may be involved in the growth, development, and stress response. Furthermore, we observed that certain CsMATE genes could be induced to exhibit expression under abiotic stress conditions such as low temperature, high salinity (NaCl), osmotic stress (PEG), and methyl jasmonate treatment (MeJA). The findings presented herein offer a crucial theoretical foundation for elucidating the biological functions of CsMATE genes, particularly in response to abiotic stress, and furnish valuable potential genetic resources for tea plant resistance breeding.

Effect of different pooled qc samples on data quality during an inter-batch experiment in untargeted UHPLC-HRMS analysis on two different MS platforms.

Quality control (QC) samples are commonly used in metabolomics approaches for three main reasons: (i) the initial conditioning of the column; (ii) the correction of analytical drift especially between batches; and (iii) the evaluation of measurement precision. In practice, there are several ways to prepare and conserve QC samples. The most common in untargeted metabolomics is to pool samples after or before extraction, in order to obtain pooled QC samples accounting, respectively, for analytical variance or for both analytical and sample preparation variances. In this study, focusing on untargeted analysis of tea (Camellia sinensis) leaves, we compared three ways of preparing pooled QC samples (two usual and one unusual QC sample preparations) and their efficiency to improve data quality in terms of inter-batch correction, measurement precision, and VIP candidates selection on datasets obtained using two mass spectrometry (MS) technologies (Orbitrap and time of flight (QToF)). We also investigated the effect of data processing modalities, based on the different QC preparations, on data loss and on the global structure of the datasets. Generally, our results show that usual QC sample preparation leads to comparable datasets quality in terms of precision and dispersion on both MS instruments. They also show that QC preparation is crucial for VIP selection; in fact, up to 54% of biomarkers candidates were specific of the QC preparation type used for data processing.

A defensive pathway from NAC and TCP transcription factors activates a BAHD acyltransferase for (Z)-3-hexenyl acetate biosynthesis to resist herbivore in tea plant (Camellia sinensis).

Numerous herbivore-induced plant volatiles (HIPVs) play important roles in plant defense. In tea plants (Camellia sinensis), (Z)-3-hexenyl acetate (3-HAC) has been characterized as associated with resistance to herbivores. To date, how tea plants biosynthesize and regulate 3-HAC to resist herbivores remain unclear. Based on transcriptomes assembled from Ectropis obliqua-fed leaves, a cDNA encoding BAHD acyltransferase, namely CsCHAT1, was highly induced in leaves fed with E. obliqua. Enzymatic assays showed that CsCHAT1 converted (Z)-3-hexenol into 3-HAC. Further suppression of CsCHAT1 expression reduced the accumulation of 3-HAC and lowered the resistance of tea plants to E. obliqua, while 3-HAC replenishment rescued the reduced resistance of CsCHAT1-silenced tea plants against E. obliqua. Two transcription factors (TFs), CsNAC30 and CsTCP11, were co-expressed with CsCHAT1. An integrative approach of biochemistry, DNA-protein interaction, gene silencing, and metabolic profiling revealed that the two TFs positively regulated the expression of CsCHAT1. The suppression of either one decreased the production of 3-HAC and eliminated the resistance of tea plants to E. obliqua. Notably, the suppression of either one considerably impaired JA-induced 3-HAC biosynthesis in tea plant. The proposed pathway can be targeted for innovative agro-biotechnologies protecting tea plants from damage by E. obliqua.

Deciphering the anthocyanin metabolism gene network in tea plant (Camellia sinensis) through structural equation modeling

BackgroundTea is an important cash crop that significantly contributes to rural development, poverty reduction and food security in many developing countries. It provides livelihoods for millions of smallholder producers and aids their economic stability. Anthocyanins in tea leaves provides excellent commercial quality and germplasm exploration potential. These compounds give tea leaves vibrant colors and increase health benefits. The current understanding of the synergistic regulation mechanisms responsible for color changes in purple tea, attributed to anthocyanin degradation, remains unclear.ResultsIn this study, we have identified 30 gene families within the genome that are associated to with anthocyanin metabolism from tea. These gene families play distinct roles in the biosynthesis of anthocyanin including the formation of the core, structure, modification of the molecular framework, facilitation of transport process, regulation of gene expression, breakdown pathways, sugar transportation and iron ion respectively. Subsequently, we investigated the synergistic mechanisms of anthocyanin metabolism related gene families within tea leaves using structural equation modeling. The results showed that sugar transport positively affects anthocyanin transportation, and promotes anthocyanin degradation during leaf pigmentation, whereas, it inhibits anthocyanin degradation during the fading of leaf color. Further, Iron ions facilitate the degradation of anthocyanins during their deposition and conversely, impede this degradation process during digestion. These finding suggests that tea plants may regulate the synthesis and degradation of anthocyanins through sugar transport and iron ions ensure healthy levels and vibrant colors.ConclusionsOur study contributes valuable information into the dynamic equilibrium anthocyanin mechanism and sheds light on complex regulatory mechanisms that govern the synthesis, transport and degradation of these pigments. These insights could be further used to develop strategies for enhancing anthocyanins content in unique tea germplasm to aid tea industry in producing new tea products with increased health benefits and aesthetic appeals.

Research on heavy metal enrichment and transportation in tea plant-soil systems of different varieties.

This study aimed to investigate heavy metal enrichment in different tea plant varieties and their distribution within different plant parts and to clarify the behavioral characteristics of heavy metals in the tea tree-soil system and their influencing factors. In this study, soil samples were collected from the root zones of 13 tea tree varieties in Guizhou, which had been planted for 10years. The aim was to compare the physicochemical properties of tea plantation soils under soil-forming matrixes and consistent management. Additionally, the study investigated the enrichment and transportation patterns of Cd, Cr, Cu, Pb, Zn, and Ni in the tea tree-soil systems of different tea tree varieties. The results showed that the planting of tea trees decreased the soil pH by 0.5; soil nutrients decreased; soil Pb, Cr, Ni, Cu, and Zn contents in the root zone increased; and Cd content decreased. Heavy metals were mainly enriched in the roots, and Zn, Cu, Ni, and other elements related to the protein and enzyme synthesis of tea trees could be mostly transported to the stems and leaves. There were significant differences in the enrichment and transportation of heavy metals among the different tea tree varieties. Under consistent soil-forming parent material, soil pH, organic matter, nutrients, and other indices only had a significant effect on heavy metal enrichment in the tea tree roots. Therefore, in areas with high background soil heavy metal contents, the construction of tea plantations should be based on regional soil environmental conditions to choose tea tree varieties with low heavy metal enrichment capacities to avoid the risk of high background soil heavy metals on the safe production of tea for consumers.