Skip to main content
Download PDF

Response of photosynthetic capacity to ecological factors and its relationship with EGCG biosynthesis of tea plant (Camellia sinensis)

BMC Plant Biology volume 25, Article number: 199 (2025) Cite this article

Abstract

Background

Epigallocatechin gallate (EGCG) imparts unique health benefits and flavour to tea. Photosynthesis plays a crucial role in modulating secondary metabolite production in plants, and this study investigated its impact on the biosynthesis of EGCG in tea plants under different ecological conditions.

Results

Enhanced photosynthetic activity and the increased EGCG content, total esterified catechins (TEC), total catechins (TC) responded synchronously to changes in ecological factors. The photosynthetic capacity of tea plants and the EGCG content fit surface model equations (Extreme 2D and Polynomial 2D) and multiple regression equations (R2 > 70%). Additionally, logistic regression and ROC curves revealed that photosynthetic capacity was related to EGCG accumulation patterns in response to ecological variations. Upon perceiving ecological changes, the response of photosynthesis-related genes (CspsaA from photosystem I, CspsbB, CspsbC from photosystem II, and CsLHCB3 from the antenna protein pathway) was associated to carbon cycle-related genes (CsALDO, CsACOX, CsICDH, Csrbcs), which mediated the expression of CsPAL in the phenylalanine pathway; CsaroDE in the shikimate pathway; and CsCHS, CsF3H, CsF3’H, and CsANS in the flavonoid pathway. Eventually, this influenced the accumulation of EGCG and its precursors (gallic acid and epigallocatechin) in tea plants.

Conclusions

This study reveals the effects of photosynthesis on EGCG biosynthesis in response to ecological factors, providing insights for optimizing tea cultivation and quality.

Peer Review reports

Background

Tea, one of the three most popular nonalcoholic beverages worldwide, is rich in catechins and other metabolites. Catechins, as the most important bioactive compounds in tea plants, can prevented cancer and improved cardiovascular health [1,2,3]. As a unique catechin currently found in large quantities only in tea plants [4, 5], EGCG imparts unique health benefits and flavour to tea, determining the quality of oolong and green teas [6]. In particular, its health benefits include antioxidant, anticancer, and cardiovascular protective effects [7,8,9,10]. Esterified catechins, accounting for more than 70% of total catechins, include catechin gallate (CG), gallocatechin gallate (GCG), epicatechin gallate (ECG), and epigallocatechin gallate (EGCG) [11]. EGCG, the most abundant esterified catechin, is biosynthesized from nonesterified catechins and metabolites of the shikimate pathway, catalysed by serine carboxypeptidase-like acyltransferases (SCPL-ATs) [12]. The biosynthesis of nonesterified catechins involves the acyltransferase family and leucoanthocyanidin reductases in the phenylalanine and flavonoid pathways, including catechin (C), epicatechin (EC), and epigallocatechin (EGC) [13].

The accumulation of EGCG and its precursors is affected by photosynthesis [14] Moreover, tea leaves from various leaf positions and developmental processes as well as chlorotic leaves affect catechin accumulation through photosynthesis regulation [15,16,17]. The total catechin content is lower in albino and chlorophyll-deficient tea plants, while the esterified catechin content is greater in green-leaf tea plants [18, 19]. These findings suggest a strong relationship between chlorophyll levels and catechin concentrations. Tea plants accumulate amounts of catechins during the day, which is when photosynthesis occurs [20,21,22]. This concurrent increase is also observed in reactions to higher CO2 levels, summer conditions, increased nitrogen fertilization, moderately high temperatures, and selenium nanomaterial applications [23,24,25,26,27]. Conversely, catechin levels decrease alongside photosynthetic pigment concentrations, chlorophyll fluorescence parameters (Fv/Fm, ΦPSII), and photosynthetic rates in response to acid rain (pH 2.5), Cd stress, and E. Onukii infestation [28,29,30]. Many previous studies have indicated that catechin content and photosynthesis exhibit similar response patterns to environmental stimuli. However, during tea leaf development, the relationship between catechin content and photosynthesis showed opposite trends [17, 31]. Notably, the total catechin and chlorophyll contents exhibit opposite patterns in response to ultraviolet A/B treatment, red light treatment, magnesium deficiency, increased P and K contents, and unpruned treatments [32,33,34,35,36].

Photosynthesis serves as the core of food production and biochemistry on Earth, and affects plant resistance and crop quality by regulating carbohydrate metabolism [37, 38]. The gas exchange, stomatal conductance, net photosynthetic rate, and chlorophyll fluorescence parameters in tea leaves are affected by seasonal and diurnal changes in the ecological environment [39,40,41], resulting in reduced photosynthetic pigment content and capacity during the peak of summer [42, 43]. The net photosynthetic rate of mature tea leaves exhibits a typical asymptotic response to increasing light intensity and is also temperature-dependent [44, 45]. The photosynthesis of tea plants is influenced by light, temperature, and moisture [46,47,48,49], which subsequently affects metabolite accumulation.

In summary, as influenced by ecological factors, photosynthesis is closely related to EGCG biosynthesis in tea plants. However, the complex interplay and dynamic nature of outdoor ecological factors make it challenging to investigate precise response mechanisms and intrinsic relationships. To investigate the precise responses of photosynthesis to ecological factors and its relationship with EGCG biosynthesis, we altered ecological factors in the artificial climate chamber, including environmental temperature (15℃, 20℃, 25 °C, and 30 °C), air relative humidity (40% AH, 50% AH, 70% AH, and 90% AH), substrate relative humidity (65% RH, 70% RH, 75% RH, 80% RH, and 85% RH), and interactions among multiple ecological factors (T1-T17).

Methods

Plant materials and cultivation conditions

Tea cutting treatments

The tea cuttings of the “Huangdan” tea cultivar (Camellia sinensis var. sinensis cv. Huangdan) were sourced from the Qianhe Tea Cooperative in Anxi County, China. The cuttings were cultivated for one year, after which the soil was washed and disinfected with potassium permanganate to eliminate pests and diseases. The fibrous roots, lateral branches, and apical tips were pruned, retaining a 20–25 cm stem with 3–4 leaves.

Transplantation of tea cuttings

The substrate used for transplantation consisted of a mixture of coconut bran, peat soil, vermiculite, and perlite in a ratio of 2:2:1:1. Seedling bags measuring 20 cm in height and 18 cm in diameter were prepared, each filled with two-thirds of the substrate. Each bag contained a single treated tea cutting. Transplanted seedlings were irrigated with 500 mL of rooting solution and maintained under controlled conditions in an artificial climate chamber.

Culture conditions

The artificial climate chamber, LED lamps, nutrient solution, and planting substrate were provided by Zhongke Bio Co., Ltd., Fujian, China. The lighting conditions were set to a 12-hour light/12-hour dark photoperiod (light: 6:00–18:00). The LED lamp model used was ZK-SL200-0S01/, with a red: blue light ratio of 3.7:1. The CO₂ concentration in the chamber was maintained at 750 ± 50 µmol·mol⁻¹. The nutrient solution was optimized based on the protocol of Shigeki Konishi et al. [50]. During the adaptation period, 300 mL of nutrient solution (EC = 1.0–1.2, pH = 5.5) was added to each pot weekly.

Treatment conditions

Each treatment group consisted of 24–30 tea plants, with three biological replicates. After a period of normal growth, the tea plants were subjected to different ecological factor treatments. Temperature treatments were designed as T15℃, T20℃, T25℃, T30℃, and T35℃, based on the growth habits of tea plants. Relative air humidity treatments included 40% AH, 50% AH, 70% AH, and 90% AH. Relative substrate humidity was controlled using a weighing method, with treatments set at 65% RH, 70% RH, 75% RH, 80% RH, and 85% RH. The interaction of ecological factors was evaluated through interaction treatments involving temperature, light intensity, and substrate relative humidity (T1–T17), designed using the response surface method. Among these, treatments T1–T5 were conducted under identical environmental parameters. Detailed ecological factor parameters are provided in Supplementary Table 1.

Samples collection

Tea samples were collected using the standard of one bud and one leaf (as shown in Supplementary Fig. 1). Half of the collected samples were oven-dried and stored at -20 °C for subsequent HPLC analysis. The remaining samples were immediately frozen in liquid nitrogen and stored at -80 °C for qPCR analysis.

Measurement of photosynthesis and catechin content

The second or third mature leaves were selected for measuring photosynthesis-related parameters (Supplementary Fig. 2). The 95% ethanol extraction method was used to determine the photosynthetic pigment content, IMAGING-PAM was used to measure the chlorophyll fluorescence parameters, and the a Li-6800 portable photosynthesis system was used to measure the photosynthetic characteristics of tea plants. The specific methods used were described by Xiang Ping et al. [51].

The catechins content was determined was performed according to the method described by Lin Jinke et al. [52]. Tea samples (0.2 g, accurate to 0.0001 g) were weighed into a 10 ml centrifuge tube, and 5 ml of 70% methanol solution heated in a water bath was added. After being shaken by a mixer, the tea sample was immediately transferred to a 70 °C water bath. The tea sample was immersed for 10 min and shaken once at 5 min, and the centrifuge tube was transferred to the centrifuge after 10 min (3500 r/min, 10 min). The residue and then 70% methanol solution 5 ml extracted once, and this process was repeated as above. The combined extract volume was made up to 10 ml, shaken, and pour 1 ml liquor into a 10 mL volumetric flask with a pipet and volume it to 10 mL with a stable solution and then filtered with a 0.45 µM membrane before being analysed by HPLC. The HPLC instrument was Waters Acquity UPLC HSS T3 column (2.1*100 mm, RP181.7 μm) with 35 ℃ column temperature.

Mobile phase A consisted of 98% pure water + 0.02% EDTA-2Na + 2% glacial acetic acid, and Mobile phase B consisted of 98% acetonitrile and 2% glacial acetic acid. PDA detection conditions were as follows: scanning range of 200–400 nm; characteristic detection wavelength of 278 nm; scanning time of 10 min, and injection volume, 2ul. Standard stock solution is listed as follows: a caffeine stock solution (2.00 mg/ml), gallic acid (GA) stock solution (0.100 mg/ml), and various catechin stock solutions: C (1.00 mg/ml), EC (1.00 mg/ml), EGC (2.00 mg/ml), EGCG (2.00 mg/), and ECG (2.00 mg/ml). All samples were analysed with three biological replicates, and the average values were used for data analysis.

RNA extraction and quantitative RT‒PCR

RNA extraction and qRT‒PCR were conducted using kits from Tiangen Biotech Co., Ltd. (https://www.tiangen.com, Beijing, China). Total RNA was extracted using the RNAprep Pure Plant Kit according to the manufacturer’s protocol, and the first-strand cDNA synthesis was performed using the Script RT Kit. Quantitative real-time PCR (qRT-PCR) was carried out according to the instructions of the SuperReal PreMix Plus (SYBR Green) kit on the CFX Connect Real-Time PCR Detection System (https://www.bio-rad.com). The 20 µl reaction system consisted of 0.6 µl forward and reverse primers, 1 µl cDNA, 10 µl Mix, and 7.8 µl ddH₂O. The qRT-PCR program included: pre-denaturation (95 °C for 15 min), annealing and extension (95 °C for 10 s, 61 °C for 32 s, 40 cycles), and a melt curve (95 °C for 15 s, 60 °C for 1 min, 95 °C for 30 s, 60 °C for 15 s). GAPDH was used as the internal reference gene for qRT‒PCR, and primer sequences are listed in Supplementary Table 2. Relative expression was calculated using the 2−△△Ct method.

Data analysis and visualization

Statistical analyses, including significance testing, correlation analysis, logistic regression and curve analysis, partial least squares (PLS) analysis, multiple regression analysis and receiver operating characteristic (ROC) curve analysis, were performed using SPSS 21.0. Surface fitting was analysed by Origin 2021. The data of co-expression was analyzed by https://www.bioinformatics.com.cn (last accessed on 30 Aug 2024), and the results were visualized via Cytoscape v3.10.2. K-means analysis was conducted on the cloud platform (https://cloud.metware.cn). Specific websites (https://bioinformatics.psb.ugent.be/webtools/plantcare/html) and TB tools were used for predicting and visualizing gene promoter response elements [53]. Data visualization was also performed via the ChiPlot website (https://www.chiplot.online).

Results

Response of tea plant photosynthetic ability to changes in ecological factors

Photosynthetic pigment content and fluorescence parameters

The contents of chlorophyll a, chlorophyll b, and carotenoids of samples under the at 20 °C, 90% air humidity (AH), and 65% relative humidity (RH) treatment were significantly greater than those of samples under the other treatments, respectively. Moderately elevated temperature, high air relative humidity, and increased substrate relative humidity enhanced the chlorophyll fluorescence parameters, non-photochemical quenching (NPQ), and electron transport rate (ETR) (Supplementary Fig. 3, Supplementary Fig. 4). The photosynthetic pigment content responded to the interaction of ecological factors as follows (Fig. 1A): low-light intensity treatments (T6, T7, T10, and T14) > moderate light intensity treatments (T1-5, T11, T12, T15, and T16) > high light intensity treatments (T8, T9, T13, and T17). These findings suggest that an increasing light intensity decreases the photosynthetic pigments in tea plants, resulting in greener leaves under low-light conditions (Fig. 1B). The chlorophyll fluorescence parameters also responded differently to the interaction of ecological factors (Supplementary Table 3). In particular, Fv/Fm and Y(II) were elevated in samples under the T6, T7, and T10 treatments, indicating that the photochemical efficiency of tea leaves improved under low-light conditions. NPQ was significantly greater in samples under the T8, T9, and T15 treatments than that in samples under the other treatments, suggesting that moderate humidity stress enhances NPQ. The ETR was enhanced by low-light intensity at elevated temperatures (T6, T7 > T8, T9) and by higher RHs at relatively lower temperatures (T16 > T14, T15, T17). In summary, the photosynthetic pigment content and fluorescence parameters of tea plants are enhanced primarily by low-light intensity, with additional interactions coming from temperature and substrate relative humidity.

Photosynthetic characteristics

When ecological factors changed individually, moderately elevated temperatures of 25 °C and 30 °C, a relative humidity of 70% AH, and the higher substrate relative humidities (70% RH and 80% RH) improved the photosynthetic characteristics of tea leaves (Supplementary Fig. 5). At 20 °C, the net photosynthetic rate (Pn) under the 250 µmol·m⁻²·s⁻¹ treatment was significantly greater than that under the 150 µmol·m⁻²·s⁻¹ and 350 µmol·m⁻²·s⁻¹ treatments (T15, T16 > T14, T17), which was consistent with the pattern observed at 30 °C (T11, T12 > T10, T13). The transpiration rate (Tr) and stomatal conductance (Gs) were lower under the T8 and T9 treatments, indicating that high-light intensity (350 µmol·m⁻²·s⁻¹) induced photoinhibition in tea plants at moderately elevated temperatures (Supplementary Fig. 6). Hence, the photosynthetic characteristics of tea leaves are predominantly affected by the interaction between temperature and light.

Photosynthetic capacity

The F value, representing overall photosynthetic capacity, was significantly lower under temperatures of 15 °C and 30 °C, low air relative humidities of 40% AH and 50% AH, and substrate relative humidities of 65% RH and 85% RH than under the conditions of other treatments (Supplementary Fig. 6E). Under constant temperature conditions, F responded primarily to changes in light intensity. The order of F was as follows: at 25℃, T6, T7 > T8, T9; at 30℃, T10 > T11, T12, T13; and at 20℃, T14 > T17. These findings indicate that the photosynthetic capacity of tea plants is affected by the interaction of temperature and light intensity, with high-light intensity inhibiting photosynthetic capacity at a constant temperature (Fig. 1C). Furthermore, high substrate relative humidity promoted the photosynthetic capacity under low-temperature conditions (T16 > T15).

Relationship between EGCG metabolism and the photosynthetic capacity of tea plants in response to ecological factors

Fig. 1
figure 1

Response of tea plant photosynthesis to interactions of ecological factors, and T1-T17 represents the 17 experimental treatments of ecological factors interaction; A represents photosynthetic pigment content, and the L150, L250, L350 represent the treatments by the same light intensity (µmol·m− 2·s− 1). B represents leaf color, and the first row represents the treatments by T1-T5 from left to right. Similarly, the second row represents T6-T9, the third row represents T10-T13, and the fourth row represents T14-T17; C represents photosynthetic capacity, and the F-value represents the score of the principal component analysis of the photosynthetic index under the interaction of ecological factors. Different lowercase letters represent significant differences (P < 0.05)

Full size image

Correlation analysis

The EGCG content was significantly correlated with the net photosynthetic rate, transpiration rate (Pn), intercellular CO2 concentration (Ci), chlorophyll a/b, and NPQ. These photosynthetic parameters were also significantly correlated with the content of EC, L ± C, ECG, TNEC, and TEC. Chlorophyll a/b, chlorophyll a, chlorophyll b, and total chlorophyll were significantly correlated with the EC and GC contents. The NPQ, Fo, Y(II), and ETR were correlated with 8 catechin indices (Supplementary Table 4, Fig. 2A). Mantel correlation analysis revealed that photosynthetic parameters significantly affected the content of EGCG and its precursors (Fig. 21C). Therefore, the net photosynthetic rate, transpiration rate, intercellular CO2 concentration, chlorophyll content, NPQ, Fo, Y(II), and ETR significantly influence the accumulation of EGCG and its related metabolites. The total esterified catechins were significantly negatively correlated with the intercellular CO2 concentration, chlorophyll a/b, and net photosynthetic rate, while being significantly positively correlated with the transpiration rate, chlorophyll b, and NPQ (Supplementary Table 4, Fig. 2B). The total nonesterified catechins and total esterified catechins had opposite correlations with these photosynthetic parameters, indicating that photosynthesis has contrasting effects on esterified and nonesterified catechins in response to ecological factors.

Partial least squares analysis

The variable importance in projection (VIP) calculated using the PLS model indicated that the transpiration rate, intercellular CO2 concentration, chlorophyll a/b, Fv/Fm, and NPQ had the most significant effect on the EGCG content (Fig. 2E). For other catechins related to EGCG metabolism, the VIP values for the transpiration rate and intercellular CO2 concentration for eight catechin indices were greater than 1; in particular, or GC content, in which the VIP value exceeded 1.5 (Fig. 2D and E, and 2 F). Furthermore, the VIP values for chlorophyll a/b and NPQ were above 1 for all the catechin indices except for EGC and GCG. These findings indicate that the transpiration rate, intercellular CO2 concentration, chlorophyll a/b, and NPQ significantly influence EGCG metabolism in tea plants, with NPQ having a major effect on the accumulation of EGCG and esterified catechins.

Multiple regression analysis and surface fitting analysis

Logistic regression analysis was conducted with the consistency of the trends between the F value and EGCG content as the dependent variable. The constant and significance of the logistic regression model were 2.161 and 0.024 (< 0.05), respectively, indicating that the F value had a significant positive effect on the consistency between the photosynthetic capacity and EGCG content. The ROC curve analysis revealed that the diagnostic accuracy of photosynthetic capacity, in determining whether the F value and EGCG content changed in synchrony, was 81.0% (Fig. 2A). Redundancy analysis (RDA) indicated that the photosynthetic parameters, particularly the chlorophyll fluorescence parameters, significantly affected EGCG metabolism (Fig. 3F). Thus, the photosynthetic capacity of tea plants significantly influences the response of the EGCG content to ecological factors, with photosynthetic capacity and EGCG content covarying within a certain range.

When ecological factors change individually, the relationship between F-value and EGCG content can be described by a surface mathematical model. Under different temperature and AH treatments, the F-value and EGCG content fit the Extreme 2D surface model equation (R2 > 90%, Fig. 3C and D). When ecological factors change interactively, the multiple regression model between photosynthetic parameters and EGCG content had a Durbin-Watson value of 1.272, significance < 0.001, and R2 > 70%. Furthermore, the standardized residuals of the multiple regression model conformed to a normal distribution (Supplementary Fig. 7), and the predicted TC content from the equation fit well with the actual measured TC content (Fig. 3B). Additionally, when ecological factors change interactively, the F value representing photosynthetic capacity and the EGCG content fit the Polynomial 2D surface model (Fig. 3E), with R2 = 91.2%. Therefore, the strong fit of both the multiple regression model and the surface fitting model demonstrates that photosynthetic capacity influences EGCG accumulation in response to ecological factors.

Fig. 2
figure 2

Relationship between photosynthesis and EGCG metabolism in response to ecological factor changes. A and B show the correlation between EGCG and NPQ (non-photochemical quenching), between TEC and NPQ, respectively. C represents the Mantel correlation between photosynthesis and catechin content. D, E, and F represent VIP values of photosynthesis-related indices for non-ester catechin content, EGCG and its precursor content, and ester catechin content in the PLS model

Full size image
Fig. 3
figure 3

Mathematical model fitting of tea plant photosynthesis and catechin content. A represents the ROC curve; B represents multiple regression fitting; C, D, and E represent surface fitting of tea plant EGCG content and photosynthetic capacity under temperature treatment, relative humidity treatment, and ecological factor interaction treatment, respectively. F represents redundancy analysis (RDA) of photosynthesis-related parameters on EGCG metabolism

Full size image

Molecular relation between photosynthesis and EGCG biosynthesis in tea plants

Promoter response elements of EGCG biosynthesis-related genes

The prediction of promoter response elements revealed that the promoter regions of each EGCG biosynthesis-related structural gene contain multiple light response elements, particularly in the promoters of CsANS, CsC4H, CsCHI, CsDFR, CsF3H, CsLAR, and CsSCPL (Supplementary Fig. 8). Thus, light response elements significantly regulate the expression levels of EGCG biosynthesis-related genes.

Cooperative response of EGCG biosynthesis-related genes and photosynthesis-related genes to individual ecological factor changes

Fig. 4
figure 4

Response of tea plant photosynthesis-related gene expression to individual ecological factor changes. A, B, and C represent temperature treatment, air relative humidity treatment, and substrate relative humidity, respectively

Full size image

The expression levels of photosynthesis-related genes in tea plants significantly respond to changes in environmental temperature, air relative humidity, and substrate relative humidity. Under different temperature treatments, the expression of four CspsbB, CsrbcS, and CsICDH genes were upregulated at 20 °C and 30 °C, whereas the expressions of CsACOX and CsALDO genes were highest at 30 °C (Fig. 4A). Compared with the other air relative humidity treatments, the 40% AH treatment suppressed the expression of all photosynthesis-related genes, whereas an increase in air relative humidity significantly upregulated their expression (Fig. 4B). Similarly, lower substrate relative humidity (65% RH) inhibited the expression of most photosynthesis-related genes, while photosynthesis system-related genes (CspsbB, CspsbC, and CspsaA) were significantly upregulated under 80% RH treatment (Fig. 4C). Overall, moderate increases in temperature and moisture promote the expression of genes related to photosynthesis.

K-means analysis of gene expression levels under different temperature treatments revealed that Cluster 2 contained eight photosynthesis-related genes, including CspsbB (novel.654, novel.7046, novel.9284), CsALDO (HD.06G0010210, novel.10352), CsICDH (novel.8769), CsrbcS (HD.01G0033940), CsACOX (HD.09G0019280), and two EGCG biosynthesis-related genes (CsDE2 and CsCHS1). CspsbB (novel.9436) is co-expressed with CsaroDE1 and CsaroB, which is consistent with the relationships among CspsbC (HD.01G0035350), CspsaA (HD.06G0040030), CspsaB (HD.06G0041030), CsLHCB3 (HD.08G0026290), CsICDH (novel.8765), CsCHI, and CsSCPL (Supplementary Table 5). Thus, under various environmental temperatures, the eight photosynthesis-related genes, especially CspsbB and CsICDH, presented a coresponse trend with key genes in the shikimate pathway (CsaroDE1, CsaroB, CsaroDE2), CsCHS1, CsCHI, and CsSCPL. Under different air humidity conditions, seven photosynthesis-related genes (CspsaB, CspsbC, CspsaA, CsACOX, CsALDO, CsICDH, and CsLHCB3) and six key structural genes involved in EGCG biosynthesis (CsANS, CsCHS1, CsCHS2, CsF3’H, CsDFR2, and CsPAL) exhibited a coordinated response (Supplementary Table 6, Supplementary Fig. 9).

Both photosynthesis-related genes and EGCG biosynthesis-related genes in tea plants respond to changes in substrate relative humidity (Supplementary Table 7, Fig. 5). CsrbcS (HD.01G0033940) and CspsbB (novel.9284), along with the shikimate pathway genes CsaroDE1, CsaroDE2, and CsaroDE3, were co-upregulated under the 80% RH and 85% RH treatments (Fig. 5A). CspsaB (HD.06G0041030), CspsbC (HD.01G0035350), CspsaA (HD.06G0040030), and seven EGCG biosynthesis-related structural genes (CsCHS1, CsC4H, Cs4CL2, CsF35H, CsANR1, CsANR2, and CsPAL) exhibited the same response trend (Fig. 5B). CsLHCB3 (HD.08G0026290, novel.8769), CspsbB (novel.9436), CsACOX (HD.09G0019280), and CsICDH (novel.8765) were significantly upregulated under the 80% RH and 85% RH treatments, matching the expression trends of flavonoid pathway genes (CsCHS3, CsF3H, CsF3’H, CsANS, and CsLAR2) (Fig. 5C). Therefore, in response to substrate relative humidity changes, five photosynthesis-related genes (CsLHCB3, CspsbB, CsACOX, and CsICDH) and five flavonoid pathway genes (CsCHS3, CsF3H, CsF3’H, CsANS, CsLAR2) coregulate EGCG accumulation in tea plants. This is consistent with the relationship between chlorophyll apoproteins in the photosynthesis system (CspsaA, CspsbB, and CspsbC) and genes in the phenylpropanoid pathway (CsC4H, Cs4CL2, and CsPAL).

Coregulation of EGCG biosynthesis-related genes and photosynthesis-related genes in response to interactions among ecological factors

Fig. 5
figure 5

Co-expression of photosynthesis-related and EGCG biosynthesis-related genes in response to changes in substrate relative humidity in tea plants

Full size image

K-means clustering analysis revealed that three photosynthesis-related genes (CsatpG (HD.07G0011090), CsRPE (HD.04G0019600), and Csfbp (HD.11G0018290)) clustered with the EGCG biosynthesis-related gene CsFLS (HD.10G0015440). Eight photosynthesis-related genes (CsDECR2 (HD.04G0034050), CsLHCB1 (HD.08009904), CsPXMP2 (HD.08G0006690), CsACSL (HD.1209423, HD.1209424), CsnudC (HD.1407708), CsrpiA (HD.03G0008710), and CsPGK (novel.5030)) clustered with three EGCG biosynthesis-related genes (Cs4CL (HD.1504232, novel.8762), and CsDFR (HD.06G0036240)) in cluster 5. Cluster 6 contained two genes encoding light-harvesting proteins (CsLHCB1 (HD.07G0005110), CsLHCB3 (HD.08G0026290)) and three flavonoid pathway genes (CsF3H (HD.01G0028710), CsF3’5’H (HD.13G0004300), and CsANR (HD.12G0016700)) (Supplementary Table 8). Co-expression network analysis revealed that CsALDO and CsaroDE were synergistically upregulated, which was accompanied by the increasing EC accumulation. Meanwhile, the expression of CsANS and photosynthesis-related genes responded synchronously to changes in ecological factors, which regulated EGCG and esterified catechins (GCG, ECG) (Fig. 6).

Potential mechanism of EGCG biosynthesis in tea plants mediated by photosynthesis in response to changes in ecological factors

Fig. 6
figure 6

Co-expression network of photosynthesis-related genes mediating EGCG accumulation in response to ecological factor interactions in tea plants. Green circles represent photosynthesis-related genes, purple hexagons represent EGCG biosynthesis-related genes, and green squares and red font represent EGCG-related metabolites

Full size image

Based on the expression patterns of genes in response to both individual and interactive changes in ecological factors, the potential mechanism was drawn to illustrate the photosynthesis-mediated EGCG biosynthesis pathway. CspsbB and CspsbC from photosystem II regulate the expression of CsCHS, CsF3H, CsF3’H, CsANS, and CsaroDE. CsLHCB3, associated with the light-harvesting antenna complex, influences the expression of CsPAL and CsF3H. Additionally, the expression of the carbon cycle-related genes CsALDO, CsACOX, CsICDH, and Csrbcs, which are influenced by changes in ecological factors and photosystem-related genes, regulates the expression of CsCHS, CsF3H, CsF3’H, and CsaroDE (Fig. 7).

The potential mechanism is as follows: When tea plants perceive changes in ecological factors, the response of photosynthesis-related genes (CspsaA from photosystem I, CspsbB, CspsbC from photosystem II, and CsLHCB3 from the antenna protein pathway) regulates carbon cycle-related genes (CsALDO, CsACOX, CsICDH, and Csrbcs), thereby affecting carbon metabolism flux. These changes ultimately regulate EGCG accumulation due to affecting the availability of substrates (EGC and GA) and the gene expression of CsPAL from the phenylpropanoid pathway, CsaroDE from the shikimate pathway, and CsCHS, CsF3H, CsF3’H, and CsANS from the flavonoid pathway (Fig. 8).

Fig. 7
figure 7

Mediation of EGCG biosynthesis by photosynthesis-related genes in response to ecological factor changes in tea plants

Full size image

Discussion

Fig. 8
figure 8

Potential mechanism of EGCG biosynthesis mediated by photosynthesis in response to ecological factors in tea plants

Full size image

Photosynthesis in tea plants is influenced mainly by the interaction between temperature and light intensity

Low temperatures decrease the chlorophyll content and the expression of genes related to carotenoid metabolism [54], and low temperature and freezing stress induced photosynthetic inhibition [55, 56]. In contrast, high-temperature stress also limits plant photosynthesis [57, 58]. In this study, photosynthesis was promoted by appropriately increased temperatures; however, the optimal temperature was affected by tea variety and light intensity [59]. The interaction of ecological factors significantly affects photosynthetic indicators in tea plants. In our research, the photosynthetic capacity was influenced primarily by the interaction of temperature and light intensity [60]. Previous studies also revealed the impact of temperature and light intensity on photosynthesis. For example, shading can protect the chlorophyll content and Fv/Fm of tea plants under low temperature conditions; moreover, shading can influence Pn by regulating the canopy temperature [44, 60, 61].

In addition, low temperatures exacerbate the light suppression effect on bleached tea leaves under strong light conditions [62]. The interaction between air humidity and substrate relative humidity, as well as the interaction between temperature and humidity, can also affect photosynthesis in tea plants [26]. We speculate that inconsistencies with outdoor studies may be due to the smaller range of interaction changes between temperature and light intensity during short-time studies. Shading promotes the accumulation of chlorophyll and the photosynthetic rate in tea leaves, whereas excessively high light intensity causes light inhibition in tea plants, accompanied by a decrease in Fv/Fm [41, 63, 64]. This study revealed that lower light intensity promoted photosynthesis at 25℃ and 30℃, possibly because the combined increase in temperature and light intensity led to excessive light absorption and photoinhibition in tea plants [65].

Photosynthesis-related genes mediate EGCG biosynthesis in tea plants

Flavonoid biosynthesis is closely linked to photosynthesis in tea plants [14]. Differentially expressed genes (DEGs) from various developmental stages, different proteins following glyphosate treatment, and DEGs resulting from light changes are collectively enriched in pathways associated with photosynthesis and catechin biosynthesis [15, 66, 67]. Photosynthesis influences the expression of transcription factors and structural genes associated with catechin biosynthesis in response to variations in light intensity, a process linked to the regulation of CsSCPL and the shikimic acid pathway involving CsaroB and CsaroDE [51, 68]. The light reaction product NADPH provides electron donors for important enzymes involved in catechin biosynthesis, such as cyp450 (C4H/CYP73, F3′H/CYP75B, F3′5′H/CYP75A), while the AtHB2 protein mediates the light avoidance response by disrupting the activity of the CsANS promoter [69, 70]. In this study, we found that the chlorophyll apo-protein and photosynthesis-antenna protein-related genes mediate EGCG biosynthesis. Previous studies have shown that PIF1 may inhibit the decline of catechins (C) and EGCG by regulating DFR, F3’H, F3H, 4CL, and PAL in chlorotic leaves [16]. Moreover, we observed that the expression of genes related to catechin biosynthesis (ANR, CHI) and photosynthesis (Lhcb1, Lhcb3, POR) decreased in albino tea plants [71]. Therefore, our study shows that the synergetic response between EGCG biosynthesis-related genes and photosynthesis-related genes, and the regulatory mechanism can be formed through validation experiments in the future.

Enhanced photosynthesis and the accumulation of its products increased the availability of catechin biosynthesis precursors in CO2 elevated conditon [72], unpruning tea, mature tea leaves [73], and albino tea leaves [74], suggesting that photosynthesis may influence catechin synthesis by providing a carbon source [75]. Similarly, active photosynthesis enhances catechin accumulation, which is related to carbon-nitrogen metabolism and its flow toward secondary metabolism [24, 27, 36, 76]. This study identified four carbon cycle-related genes that contribute to the mediation of catechin biosynthesis by photosynthesis, which is consistent with the effect of shade on catechin content through the regulation of carbon-cycle genes [77]. Consequently, the flow of carbon-nitrogen metabolism and the regulation of related genes might represent crucial pathways by which photosynthesis mediates catechin metabolism. Our previous research revealed substrate competition between phenolic acids and the flavonoid pathway under the influence of interacting ecological factors [78]. Additionally, the levels of two flavonoid compounds increased markedly under drought stress, whereas the levels of all types of caffeoylquinic acid decreased [79]. In summary, our research suggested that photosynthesis regulates catechins accumulation through carbon cycling, but the exact metabolic flow and substrate competition need to be further verified.

Conclusion

This study revealed that photosynthetic capacity significantly affected the response of catechins content to ecological factors, with opposite effects on esterified catechins and nonesterified catechins. Photosynthetic activity and EGCG content responded synchronously to changes in ecological factors. The expression of genes encoding chlorophyll apoproteins (CspsaA, CspsbB, and CspsbC) and the light-harvesting complex II chlorophyll a/b-binding protein (CsLHCB3 ) in the photosynthetic system, as well as CsALDO, CsACOX, CsICDH, and Csrbcs in the carbon metabolism pathway, were altered. These changes ultimately regulated the EGCG content by affecting the availability of substrates and the expression of CsPAL in the phenylpropanoid pathway, CsaroDE in the shikimate pathway, and CsCHS, CsF3H, CsF3’H, and CsANS in the flavonoid pathway. This study elucidates the mediating role of photosynthetic capacity on EGCG biosynthesis in response to ecological factors, and contributes to the understanding of the relationship between environmental adaptation and secondary metabolism in tea plants.

Data availability

The datasets used and/or analysed during the current study available from the corresponding author on reasonable request (ljk213@163.com).

Abbreviations

EGCG:

Epigallocatechin gallate

CG:

Catechingallate

GCG:

Gallocatechin gallate

ECG:

Epicatechingallate

C:

Catechin

EC:

Epicatechin

EGC:

Epigallocatechin

GA:

Gallic acid

Pn:

Net photosynthetic rate

Tr:

Transpiration rate

ETR:

Electron transfer rate

Gs:

Stomatal conductance

PCA:

Principal component analysis

PLS:

Partial least square

TC:

Total catechins

TNEC:

Total nonesterified catechins

TEC:

Total esterified catechins

PAL:

Phenylalanine ammonialyase

C4H:

Cinnamate 4-hydroxylase

4CL:

4-coumaroyl-CoAligase

CHS:

Chalcone synthase

CHI:

Chalcone isomerase

F3H:

Flavanone 3-hydroxylase

F3’H:

Flavonoid 3’-hydroxylase

F3’5’H:

Flavonoid 3’,5’-hydroxylase

DFR:

Dihydroflavonol 4-reductase

LAR:

Leucoanthocyanidin reductase

ANS:

Anthocyanidin synthase

ANR:

Anthocyanidin reductase

SCPL:

Serine carboxypeptidase-like

psaA:

Photosystem I P700 chlorophyll a apoprotein A1

psaB:

Photosystem I P700 chlorophyll a apoprotein A2

psbA:

Photosystem II P680 reaction center D1 protein

psbB:

Photosystem II CP47 chlorophyll apoprotein

psbC:

Photosystem II CP43 chlorophyll apoprotein

LHCB:

Chlorophyll a-b binding protein

ACOX:

Peroxisomal acyl-coenzyme A oxidase 1

ICDH:

Cytosolic isocitrate dehydrogenase

Rbcs:

Ribulose bisphosphate carboxylase small chain

Rbcl:

Ribulose-bisphosphate carboxylase large chain

ALDO:

Fructose-bisphosphate aldolase

PGK:

Phosphoglycerate kinase

References

  1. Zhang W et al. Genome assembly of wild tea tree DASZ reveals pedigree and selection history of tea varieties. Nat Commun 2020, 11(1).

  2. Jankun J, et al. Why drinking green tea could prevent cancer. Nature. 1997;387(6633):561–561.

    Article  PubMed  CAS  Google Scholar 

  3. Larson C. Reading the tea leaves for effects of climate change. Science. 2015;348(6238):953–4.

  4. Ahammed GJ et al. Epigallocatechin-3-Gallate (EGCG): a unique secondary metabolite with diverse roles in plant-environment interaction. Environ Exp Bot. 2023;209.

  5. Negri A et al. Molecular Targets of EpigallocatechinGallate (EGCG): A Special Focus on Signal Transduction and Cancer. Nutrients 2018, 10(12).

  6. Zhang L, et al. Chemistry and Biological activities of processed < i > Camellia sinensis teas: a Comprehensive Review. Compr Rev Food Sci Food Saf. 2019;18(5):1474–95.

    Article  PubMed  CAS  Google Scholar 

  7. Jin J-Q et al. Characterization of two O-methyltransferases involved in the biosynthesis of O-methylated catechins in tea plant. Nat Commun. 2023; 14(1).

  8. Luo Y et al. Identification of a WRKY transcriptional activator from Camellia sinensis that regulates methylated EGCG biosynthesis. Hortic Res. 2022;9.

  9. Hauber I, et al. The main green tea polyphenol epigallocatechin-3-gallate counteracts semen-mediated enhancement of HIV infection. Proc Natl Acad Sci USA. 2009;106(22):9033–8.

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  10. Xing L, et al. Recent advances in the understanding of the Health Benefits and Molecular Mechanisms Associated with Green Tea Polyphenols. J Agric Food Chem. 2019;67(4):1029–43.

    Article  PubMed  CAS  Google Scholar 

  11. Song X et al. The WRKY transcription factor CsWRKY70 regulates EGCG Biosynthesis by affecting CsLAR and CsUGT84A expressions in Tea leaves (Camellia sinensis). Horticulturae. 2023; 9(1).

  12. Ahmad MZ et al. Genome-wide analysis of Serine Carboxypeptidase-Like Acyltransferase Gene Family for Evolution and characterization of enzymes involved in the biosynthesis of Galloylated catechins in the tea plant (Camellia sinensis). Front Plant Sci. 2020;11.

  13. Wei C, et al. Draft genome sequence of Camellia sinensis var. sinensis provides insights into the evolution of the tea genome and tea quality. Proc Natl Acad Sci USA. 2018;115(18):E4151–8.

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  14. Hao X, et al. Pale green mutant analyses reveal the importance of CsGLKs in chloroplast developmental regulation and their effects on flavonoid biosynthesis in tea plant. Plant Physiol Biochem. 2020;146:392–402.

    Article  PubMed  CAS  Google Scholar 

  15. Guo F, et al. Transcriptional profiling of catechins biosynthesis genes during tea plant leaf development. Planta. 2017;246(6):1139–52.

    Article  PubMed  CAS  Google Scholar 

  16. Chen LM et al. The spatiotemporal variations of L-glutamic acid and catechins during the development of etiolated tea leaves in ‘Huangjinye’. Sci Hort. 2024;328.

  17. Li ZX, et al. Developmental changes in carbon and nitrogen metabolism affect tea quality in different leaf position. Plant Physiol Biochem. 2016;106:327–35.

    Article  PubMed  CAS  Google Scholar 

  18. Ding Y et al. Biochemical and Proteome Analysis reveal different nutritional compound compositions and Chloroplast Development situations between Purple-Red and White-Yellow Tea Plant cultivars. Horticulturae 2022, 8(8).

  19. Wei K, et al. Catechin contents in tea (Camellia sinensis) as affected by cultivar and environment and their relation to chlorophyll contents. Food Chem. 2011;125(1):44–8.

    Article  CAS  Google Scholar 

  20. Liu LL et al. From Chloroplast Biogenesis to Chlorophyll Accumulation: the interplay of light and hormones on Gene expression in Camellia sinensis cv. Shuchazao leaves. Front Plant Sci. 2020;11.

  21. Wang YS, et al. Influence of shade on flavonoid biosynthesis in tea (Camellia sinensis (L.) O. Kuntze). Sci Hort. 2012;141:7–16.

    Article  CAS  Google Scholar 

  22. Xiaohui, Wang, et al. The effects of circadian rhythm on catechin accumulation in tea leaves. Beverage Plant Res. 2021;8(1):1–9.

    Google Scholar 

  23. Ahammed GJ et al. Physiological and defense responses of tea plants to elevated CO2: a review. Front Plant Sci. 2020;11.

  24. Li X et al. Exogenous melatonin improves tea quality under moderate high temperatures by increasing epigallocatechin-3-gallate and theanine biosynthesis in Camellia sinensis L. J Plant Physiol. 2020;253.

  25. Pokharel SS et al. Influence of reduced N-fertilizer application on foliar chemicals and functional qualities of tea plants under Toxoptera aurantii infestation. BMC Plant Biol 2022, 22(1).

  26. Yao LH, et al. Seasonal variations of phenolic compounds in Australia-grown tea (Camellia sinensis). J Agric Food Chem. 2005;53(16):6477–83.

    Article  PubMed  CAS  Google Scholar 

  27. Zhang XL et al. Selenium nanomaterials enhance the nutrients and Functional Components of Fuding Dabai Tea. Nanomaterials 2024, 14(8).

  28. Zhang CY et al. Physiological and biochemical responses of tea seedlings (Camellia sinensis) to simulated acid rain conditions. Ecotoxicol Environ Saf. 2020;192.

  29. Zhang CY et al. Exogenous indole acetic acid alleviates cd toxicity in tea (Camellia sinensis). Ecotoxicol Environ Saf. 2020;190.

  30. Tian YY, et al. Morphological, physiological, and biochemical responses of two tea cultivars to Empoasca Onukii (Hemiptera: Cicadellidae) Infestation. J Econ Entomol. 2018;111(2):899–908.

    Article  PubMed  CAS  Google Scholar 

  31. Wu LY, et al. Complementary iTRAQ proteomic and transcriptomic analyses of leaves in Tea Plant (Camellia sinensis L.) with Different Maturity and Regulatory Network of Flavonoid Biosynthesis. J Proteome Res. 2019;18(1):252–64.

    PubMed  CAS  Google Scholar 

  32. Chen YY et al. Effects of Long-Term Non-Pruning on Main Quality Constituents in ‘Dancong’ Tea (Camellia sinensis) Leaves Based on Proteomics and Metabolomics Analysis. Foods 2021, 10(11).

  33. Li J, et al. Exploring the effects of Magnesium Deficiency on the Quality constituents of hydroponic-cultivated tea (Camellia sinensis) leaves. J Agric Food Chem. 2021;69(47):14278–86.

    Article  PubMed  CAS  Google Scholar 

  34. Li W et al. The Effects of Ultraviolet A/B Treatments on Anthocyanin Accumulation and Gene Expression in Dark-Purple Tea Cultivar ‘Ziyan’ (Camellia sinensis). Molecules 2020, 25(2).

  35. Shirin A, et al. Responses of secondary metabolites and transcriptomes in the tea cultivar ‘Zhong Ming 6’ (Camellia sinensis) to blue light and red light. Plant Growth Regul. 2022;98(2):343–58.

    Article  CAS  Google Scholar 

  36. Wei KL et al. Metabolomics Reveal that the high application of Phosphorus and Potassium in Tea Plantation inhibited amino-acid Accumulation but Promoted Metabolism of Flavonoid. Agronomy-Basel 2022, 12(5).

  37. Kafri M et al. Systematic identification and characterization of genes in the regulation and biogenesis of photosynthetic machinery. Cell 2023, 186(25).

  38. Liu B, et al. Factors affecting freezing tolerance: a comparative transcriptomics study between field and artificial cold acclimations in overwintering evergreens. Plant J. 2020;103(6):2279–300.

    Article  PubMed  CAS  Google Scholar 

  39. Chen CI et al. Gas exchange and chlorophyll fluorescence responses of Camellia sinensis grown under various cultivations in different seasons. Bot Stud 2024, 65(1).

  40. Oh S, et al. Photosystem II photochemical efficiency and photosynthetic capacity in leaves of tea plant (Camellia sinensis L.) under winter stress in the field. Hortic Environ Biotechnol. 2014;55(5):363–71.

    Article  CAS  Google Scholar 

  41. Netto LA, et al. Characterization of photosynthetic events and associated changes in various clones of tea (Camellia sinensis L) under low temperature conditions. J Plant Biology. 2005;48(3):326–31.

    Article  CAS  Google Scholar 

  42. Yamashita H et al. Phenotypic markers reflecting the status of overstressed tea plants subjected to repeated shade cultivation. Front Plant Sci. 2020;11.

  43. Yue C, et al. Review: the effect of light on the key pigment compounds of photosensitive etiolated tea plant. Bot Stud. 2021;62(1):21.

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  44. De Costa WAJM, et al. Ecophysiology of tea. Braz J Plant Physiol. 2007;19(4):299–332.

    Article  Google Scholar 

  45. Suresh C, Joshi, et al. Clonal variation in temperature response of photosynthesis in tea. Plant Sci. 1998;137:225–32.

    Article  Google Scholar 

  46. Dominguez-Martin MA, et al. Structures of a phycobilisome in light-harvesting and photoprotected states. Nature. 2022;609(7928):835–.

    Article  PubMed  CAS  Google Scholar 

  47. Gisriel C et al. The structure of Photosystem I acclimated to far-red light illuminates an ecologically important acclimation process in photosynthesis. Sci Adv 2020, 6(6).

  48. Mukarram M, et al. Drought: sensing, signalling, effects and tolerance in higher plants. Physiol Plant. 2021;172(2):1291–300.

    Article  PubMed  CAS  Google Scholar 

  49. Yamori W, et al. Temperature response of photosynthesis in C3, C4, and CAM plants: temperature acclimation and temperature adaptation. Photosynth Res. 2014;119(1–2):101–17.

    Article  PubMed  CAS  Google Scholar 

  50. Konishi S, et al. Stimulatory effects of aluminum on tea plants grown under low and high Phosphorus Supply. Soil Sci Plant Nutr. 1985;31(3):361–8.

    Article  CAS  Google Scholar 

  51. Xiang P et al. Light control of catechin accumulation is mediated by photosynthetic capacity in tea plant (Camellia sinensis). BMC Plant Biol 2021, 21(1).

  52. Lin J et al. Whole transcriptome analysis of three leaf stages in two cultivars and one of their F1 hybrid of Camellia sinensis L. with differing EGCG content. Tree Genet Genomes 2017, 13(1).

  53. Chen C, et al. TBtools: an integrative Toolkit developed for interactive analyses of big Biological Data. Mol Plant. 2020;13(8):1194–202.

    Article  PubMed  CAS  Google Scholar 

  54. Du YY, et al. Effect of temperature on the expression of genes related to the accumulation of chlorophylls and carotenoids in albino tea. J Hortic Sci Biotechnol. 2009;84(3):365–9.

    Article  CAS  Google Scholar 

  55. Huang S et al. Glycinebetaine facilitates the photosynthesis of albino tea under low temperature by regulating related gene methylation. Sci Hort. 2022;303.

  56. Li X, et al. Freezing stress deteriorates tea quality of new flush by inducing photosynthetic inhibition and oxidative stress in mature leaves. Sci Hort. 2018;230:155–60.

    Article  CAS  Google Scholar 

  57. He X et al. Role of Spermidine in Photosynthesis and Polyamine Metabolism in Lettuce seedlings under high-temperature stress. Plants-Basel 2022, 11(10).

  58. Muhammad I et al. Mechanisms regulating the dynamics of Photosynthesis under Abiotic stresses. Front Plant Sci. 2021;11.

  59. Carr MKV. The role of water in the growth of the tea (camellia sinensis) crop: a synthesis of research in eastern africa. 1. Water relations. Exp Agric. 2010;46(3):327–49.

    Article  Google Scholar 

  60. Mohotti AJ, et al. Diurnal variation of photosynthesis and photoinhibition in tea: effects of irradiance and nitrogen supply during growth in the field. J Exp Bot. 2002;53(367):313–22.

    Article  PubMed  CAS  Google Scholar 

  61. Zaman S et al. Effect of shading on physiological attributes and comparative transcriptome analysis of Camellia sinensis cultivar reveals tolerance mechanisms to low temperatures. Front Plant Sci. 2023;14.

  62. Oquist G, et al. Low-temperature effects on Photosynthesis and correlation with freezing Tolerance in Spring and Winter cultivars of Wheat and Rye. Plant Physiol. 1993;101(1):245–50.

    Article  PubMed  PubMed Central  Google Scholar 

  63. Barman TS, et al. Irradiance influences tea leaf (Camellia sinensis L. photosynthesis and transpiration. Photosynthetica. 2008;46(4):618–21.

    Article  CAS  Google Scholar 

  64. Li YC, et al. Metabolic regulation profiling of Carbon and Nitrogen in tea plants Camellia sinensis (L.) O. Kuntze in response to Shading. J Agric Food Chem. 2020;68(4):961–74.

    Article  PubMed  CAS  Google Scholar 

  65. Roghieh Hajiboland, et al. Effect of light intensity on photosynthesis and antioxidant defense in boron deficient tea plants. Acta Biologica Szeged. 2011;55(2):265–72.

    Google Scholar 

  66. Liu S, et al. Integrated physiological, metabolite and proteomic analysis reveal the glyphosate stress response mechanism in tea plant (Camellia sinensis). J Hazard Mater. 2023;454:131419–131419.

    Article  PubMed  CAS  Google Scholar 

  67. Jiang X et al. Transcriptomic analysis reveals mechanism of light-sensitive albinism in tea plant Camellia sinensis ‘Huangjinju’. BMC Plant Biol 2020, 20(1).

  68. Gong A-D et al. Integrated transcriptomics and metabolomics analysis of catechins, caffeine and theanine biosynthesis in tea plant (Camellia sinensis) over the course of seasons. BMC Plant Biol 2020, 20(1).

  69. Zhou Q, et al. Differential expression of genes in purple-shoot tea tender leaves and mature leaves during leaf growth. J Sci Food Agric. 2016;96(6):1982–9.

    Article  PubMed  CAS  Google Scholar 

  70. Zhang X, et al. AtHB2, a class II HD-ZIP protein, negatively regulates the expression of CsANS, which encodes a key enzyme in Camellia sinensis catechin biosynthesis. Physiol Plant. 2019;166(4):936–45.

    Article  PubMed  CAS  Google Scholar 

  71. Lu M et al. Integrated proteomics and transcriptome analysis reveal a decreased catechins metabolism in variegated tea leaves. Sci Hort. 2022;295.

  72. Li X et al. Stimulation in primary and secondary metabolism by elevated carbon dioxide alters green tea quality in Camellia sinensis L. Sci Rep. 2017;7.

  73. Mozumder NHMR et al. Metabolomic understanding of the difference between unpruning and pruning cultivation of tea (Camellia sinensis) plants. Food Res Int. 2021;140.

  74. Zhang Q et al. Integration of Metabolomics and Transcriptomics reveal the mechanism underlying Accumulation of flavonols in albino Tea leaves. Molecules 2022, 27(18).

  75. Barman TS, et al. Retention and allocation of 14C assimilates by maintenance leaves and harvest index of tea (Camellia sinensis L). Photosynthetica. 2005;43(2):283–7.

    Article  Google Scholar 

  76. Huang S, et al. Foliar application of glycinebetaine and zn fertilizer improves both the apparent and functional qualities of albino tea Camellia sinensis (L.) O. Kuntze. Food Funct. 2021;12(19):9476–85.

    Article  PubMed  CAS  Google Scholar 

  77. Elango T, et al. Influence of shading intensity on chlorophyll, carotenoid and metabolites biosynthesis to improve the quality of green tea: a review. Energy Nexus. 2023;12:100241.

    Article  CAS  Google Scholar 

  78. Xiang P et al. Integrative analyses of transcriptome and metabolome reveal comprehensive mechanisms of Epigallocatechin-3-gallate (EGCG) biosynthesis in response to ecological factors in tea plant (Camellia sinensis). Food Res Int. 2023;166.

  79. Park YJ et al. Identification of drought-responsive phenolic compounds and their biosynthetic regulation under drought stress in Camellia sinensis. Front Plant Sci. 2023;14.

Download references

Acknowledgements

Not applicable.

Funding

This work was supported by the Natural Science Foundation of Hunan Province (Grant No. 2023JJ50326), the National Natural Science Foundation of China (Grant No. 31870683), and the Scientific Research Project of Hunan University of Arts and Sciences (22BSQD16).

Author information

Authors and Affiliations

  1. College of Life and Environmental Science, Hunan University of Arts and Science, Changde, 415000, China

    Ping Xiang

  2. College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou, 350002, China

    Ping Xiang, Tukhvatshin Marat, Jiaxin Huang, Bosi Cheng, Jianghong Liu, Liangyu Wu, Meng Tan, Qiufang Zhu & Jinke Lin

  3. Institute of Photobiological Industry, Fujian Sanan Sino-Science Photobiotech Co., Ltd, Xiamen, 361008, China

    Xingjian Wang

Authors
  1. Ping Xiang
    View author publications

    Search author on:PubMed Google Scholar

  2. Tukhvatshin Marat
    View author publications

    Search author on:PubMed Google Scholar

  3. Jiaxin Huang
    View author publications

    Search author on:PubMed Google Scholar

  4. Bosi Cheng
    View author publications

    Search author on:PubMed Google Scholar

  5. Jianghong Liu
    View author publications

    Search author on:PubMed Google Scholar

  6. Xingjian Wang
    View author publications

    Search author on:PubMed Google Scholar

  7. Liangyu Wu
    View author publications

    Search author on:PubMed Google Scholar

  8. Meng Tan
    View author publications

    Search author on:PubMed Google Scholar

  9. Qiufang Zhu
    View author publications

    Search author on:PubMed Google Scholar

  10. Jinke Lin
    View author publications

    Search author on:PubMed Google Scholar

Contributions

PX investigated and performed formal analysis, and wrote the original draft of the manuscript. TM contributed to the writing, review, and editing of the manuscript. JXH developed the methodology and conducted investigations. BC conducted investigations. JHL developed the methodology. XJW developed the methodology. LYW contributed to the conceptualization and visualization of the study. MT conducted investigations. QFZ conducted investigations and curated the data. JKL contributed to the conceptualization, validation, and supervision of the study, reviewed and edited the manuscript, and administered the project.

Corresponding author

Correspondence to Jinke Lin.

Ethics declarations

Ethics approval and consent to participate

Not applicable.

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.

Additional information

Publisher’s note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Electronic supplementary material

Below is the link to the electronic supplementary material.

Supplementary Material 1

Supplementary Material 2

Rights and permissions

Open Access This article is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License, which permits any non-commercial use, sharing, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if you modified the licensed material. You do not have permission under this licence to share adapted material derived from this article or parts of it. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by-nc-nd/4.0/.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Xiang, P., Marat, T., Huang, J. et al. Response of photosynthetic capacity to ecological factors and its relationship with EGCG biosynthesis of tea plant (Camellia sinensis). BMC Plant Biol 25, 199 (2025). https://doi.org/10.1186/s12870-025-06106-8

Download citation

  • Received:

  • Accepted:

  • Published:

  • DOI: https://doi.org/10.1186/s12870-025-06106-8

Keywords

BMC Plant Biology

ISSN: 1471-2229

Contact us