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Importance: Previous evidence suggests that maternal hepatitis B virus (HBV) infection during prepregnancy or pregnancy is associated with congenital heart diseases (CHDs) in offspring. However, the association of paternal HBV infection with CHDs is not well examined. Objective: To explore the association of paternal preconception HBV infection with CHDs in offspring. Design, Setting, and Participants: This retrospective cohort study used propensity score matching of data from the Chinese National Free Preconception Checkup Project (NFPCP) from January 1, 2010, to December 31, 2018. Male participants whose wives were aged 20 to 49 years, were uninfected with HBV, and successfully conceived within 1 year after prepregnancy examination were enrolled. Data were analyzed from March 2023 to February 2024. Exposures: The primary exposure was paternal preconception HBV infection status, including uninfected, previous infection (both serum hepatitis B surface antigen and hepatitis B envelope antigen negative), and new infection (serum hepatitis B surface antigen positive). Maternal HBV immune status was further classified as immune or susceptible. Main Outcomes and Measures: The main outcome was CHDs, which were collected from the birth defect registration card of the NFPCP. Logistic regression with robust error variances was used to estimate the association between paternal preconception HBV infection and CHDs in offspring. Results: A total of 6 675 540 couples participated in the NFPCP service. After matching husbands with and without preconception HBV infection in a 1:4 ratio, 3 047 924 couples (median age of husbands, 27 years [IQR, 25-30 years]) were included in this study. Of these couples, 0.025% had offspring with CHDs. Previous paternal HBV infection was independently associated with CHDs in offspring (adjusted relative risk [ARR], 1.40; 95% CI, 1.11-1.76) compared with no infection. Similar results were obtained in subgroup analyses according to maternal HBV immune status. Compared with couples with uninfected husbands and susceptible wives, the risk of CHDs in offspring among couples with previously HBV-infected husbands was similar in couples with wives with susceptible immune status (ARR, 1.49; 95% CI, 1.10-2.03) and in those with wives with immunity (ARR, 1.49; 95%CI, 1.07-2.09). A significantly higher CHD risk in offspring was found among couples with newly infected husbands and immune wives (ARR, 1.38; 95% CI, 1.05-1.82), but there was no difference in risk among those with newly infected husbands and susceptible wives (ARR, 0.99; 95% CI, 0.72-1.36). No interactions were found between maternal immune status and paternal HBV infection. Conclusions and Relevance: In this cohort study using propensity score matching, previous paternal preconception HBV infection was associated with CHD risk in offspring. The findings suggest that personalized reproductive guidance regarding HBV screening and staying free of HBV infection should be provided for both wives and husbands.
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Importance: Many studies have reported that the interpregnancy interval (IPI) is a potential modifiable risk factor for adverse perinatal outcomes. However, the association between IPI after live birth and subsequent spontaneous abortion (SA) is unclear. Objective: To investigate the association of IPI after a healthy live birth and subsequent SA. Design, Setting, and Participants: This prospective cohort study used data from 180â¯921 women aged 20 to 49 years who had a single healthy live birth and planned for another pregnancy and who participated in the Chinese National Free Prepregnancy Checkups Project from January 1, 2010, to December 31, 2020. Statistical analysis was conducted from June 20 to October 5, 2023. Exposure: Interpregnancy interval, defined as the interval between the delivery date and conception of the subsequent pregnancy, was categorized as follows: less than 18 months, 18 to 23 months, 24 to 35 months, 36 to 59 months, and 60 months or longer. Main Outcomes and Measures: The main outcome was SA. Multivariable-adjusted odds ratios (ORs) were calculated by logistic regression models to examine the association between IPI and the risk of SA. Dose-response associations were evaluated by restricted cubic splines. Results: The analyses included 180â¯921 multiparous women (mean [SD] age at current pregnancy, 26.3 [2.8] years); 4380 SA events (2.4% of all participants) were recorded. A J-shaped association between IPI levels and SA was identified. In the fully adjusted model, compared with IPIs of 18 to 23 months, both short (<18 months) and long (≥36 months) IPIs showed an increased risk of SA (IPIs of <18 months: OR, 1.15 [95% CI, 1.04-1.27]; IPIs of 36-59 months: OR, 1.28 [95% CI, 1.15-1.43]; IPIs of ≥60 months: OR, 2.13 [95% CI, 1.78-2.56]). Results of the subgroup analysis by mode of previous delivery were consistent with the main analysis. Conclusions and Relevance: This cohort study of multiparous women suggests that an IPI of shorter than 18 months or an IPI of 36 months or longer after a healthy live birth was associated with an increased risk of subsequent SA. The findings are valuable to make a rational prepregnancy plan and may facilitate the prevention of SA and improvement in neonatal outcomes.
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Aborto Espontáneo , Intervalo entre Nacimientos , Nacimiento Vivo , Humanos , Femenino , Adulto , Intervalo entre Nacimientos/estadística & datos numéricos , Embarazo , Estudios Prospectivos , Aborto Espontáneo/epidemiología , Nacimiento Vivo/epidemiología , China/epidemiología , Persona de Mediana Edad , Adulto Joven , Factores de RiesgoRESUMEN
What is already known about this topic?: The significance of maternal liver health concerning preterm birth (PTB) is well recognized; however, there is a gap in understanding the precise influence of preconception serum alanine aminotransferase (ALT) levels on the risk of PTB. What is added by this report?: In this retrospective cohort study, a J-shaped relationship between preconception serum ALT levels and risk of PTB was observed, indicating that both significantly elevated and decreased ALT levels may contribute to the risk. What are the implications for public health practice?: Maintaining optimal preconception serum ALT levels may reduce the risk of PTB, thereby informing specific preventive measures for women of reproductive age.
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OBJECTIVES: To comprehensively assess the association of husband smoking with wives' thyrotropin abnormality. METHODS: This population-based retrospective cohort study included 2 406 090 Chinese reproductive-aged women who had participated twice in the National Free Pre-pregnancy Checkups Project between 2010 and 2020. Multivariate-adjusted odds ratios and 95% confidence intervals for subnormal and supranormal thyrotropin were estimated according to the husband's smoking status. RESULTS: Husband smoking at the first visit was associated with a 17% (15%-20%) and 26% (24%-28%) increased odds of subnormal thyrotropin and supranormal thyrotropin respectively compared to participants in neither-smoker group. In non-smoking participants with normal thyrotropin levels at the first visit, the corresponding increased risk of subnormal thyrotropin and supranormal thyrotropin at the second visit were 15% (12%-18%) and 19% (16%-21%) in contrast to participants without husband-smoking exposure. In non-smoking participants with abnormal thyrotropin levels at their first visit, husband smoking cessation was associated with 27% (17%-35%) and 36% (31%-40%) reduced odds of subnormal thyrotropin and supranormal thyrotropin at the second visit compared with the participants whose husband still smoking at the second visit. CONCLUSION: Husband smoking was associated with wives' subnormal thyrotropin and supranormal thyrotropin, and cessation of husband smoking could reduce the odds of thyrotropin abnormality. Couple-focused smoking intervention should be developed to reduce the burden of asymptomatic thyroid disease in females.
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Esposos , Tirotropina , Embarazo , Humanos , Femenino , Adulto , Estudios de Cohortes , Estudios Retrospectivos , China/epidemiologíaRESUMEN
STUDY QUESTION: Do prepregnancy peripheral leukocytes (PPLs) and their subsets influence the risk of spontaneous abortion (SAB)? SUMMARY ANSWER: PPLs and their subsets are associated with the risk of SAB. WHAT IS KNOWN ALREADY: Compelling studies have revealed the crucial role of maternal peripheral leukocytes in embryo implantation and pregnancy maintenance. Adaptive changes are made by PPLs and their subsets after conception. STUDY DESIGN, SIZE, DURATION: This population-based retrospective cohort study was based on data from the National Free Pre-pregnancy Check-up Project (NFPCP) in mainland China. Couples preparing for pregnancy within the next six months were provided with free prepregnancy health examinations and counseling services for reproductive health. The current study was based on 1 310 494 female NFPCP participants aged 20-49 who became pregnant in 2016. After sequentially excluding 235 456 participants lost to follow-up, with multiple births, and who failed to complete blood tests, a total of 1 075 038 participants were included in the primary analysis. PARTICIPANTS/MATERIALS, SETTING, METHODS: PPLs and their subset counts and ratios were measured. The main outcome was SAB. A multivariable logistic regression model was used to estimate the odds ratio (OR) and 95% CI of SAB associated with PPLs and their subsets, and restricted cubic spline (RCS) was used to estimate the nonlinear exposure-response relationship. MAIN RESULTS AND ROLE OF CHANCE: Of the included pregnant participants, a total of 35 529 SAB events (3.30%) were recorded. Compared to participants with reference values of PPLs, the ORs (95% CIs) of leukopenia and leukocytosis for SAB were 1.14 (1.09-1.20) and 0.74 (0.69-0.79), respectively. The RCS result revealed a monotonous decreasing trend (Pnonlinear < 0.05). Similar relationships were observed for the neutrophil count and ratio, monocyte count, and middle-sized cell count and ratio. The lymphocyte ratio showed a positive and nonlinear relationship with the risk of SAB (Pnonlinear < 0.05). Both eosinophils and basophils showed positive relationships with the risk of SAB (eosinophil Pnonlinear > 0.05 and basophil Pnonlinear < 0.05). LIMITATIONS, REASONS FOR CAUTION: Chemical abortion events and the cause of SAB were not collected at follow-up. Whether women with abnormal PPLs had recovered during periconception was not determined. WIDER IMPLICATIONS OF THE FINDINGS: PPLs and their subsets are associated with the risk of SAB. Leukopenia and neutropenia screening in women preparing for pregnancy and developing a feasible PPL stimulation approach should be emphasized to utilize the immune window of opportunity to prevent SAB. STUDY FUNDING/COMPETING INTEREST(S): This study was approved by the Institutional Research Review Board of the National Health and Family Planning Commission. This study was supported by the National Key Research and Development Program of China (grants 2021YFC2700705 [Y.Y.] and 2016YFC100307 [X.M.]) and the National Natural Science Foundation of China (grant no. 82003472 [L.W.]). The funding source was not involved in the study design, data collection, analysis and interpretation of the data, writing the report, or the decision to submit this article for publication. No competing interests. TRIAL REGISTRATION NUMBER: N/A.
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Aborto Inducido , Aborto Espontáneo , Leucopenia , Embarazo , Animales , Femenino , Humanos , Caballos , Aborto Espontáneo/etiología , Estudios Retrospectivos , Aborto Inducido/efectos adversos , Leucocitos , Leucopenia/complicacionesRESUMEN
Cardiovascular diseases, including hypertension, have posed a serious threat to human health in recent decades. Family-centered health promotion and disease control for the management of hypertension is gaining attention. In this study, we assessed the association between spousal educational attainment (SEA) and hypertension prevalence, awareness, and control, intending to provide new directions for family health care. A total of 71 211 191 reproductive-aged participants from the National Free NFPCP during 2013-2019 were included in the current study. Inverse probability weighting (IPW) via propensity models were used to adjust for the imbalance by SEA. Both multivariable-adjusted ORs and inverse-probability-weighted ORs were used to assess the association between SEA and the prevalence, awareness, and control of hypertension. ORs of prevalence, awareness, and control of hypertension with SEA stratified by sex, age, and residency type were also reported. Compared with participants with SEA of compulsory education, the inverse-probability-weighted ORs for hypertension were 0.97 (0.96-0.97), 0.99 (0.98-1.00), and 0.91 (0.88-0.93) for participants with SEA of senior high, college, and postgraduate, respectively. The corresponding ORs for hypertension awareness were 1.12 (1.10-1.13), 1.15 (1.13-1.16), and 1.38 (1.34-1.41). The increment of hypertension control associated with SEA was only identified in urban areas. Modification analyses revealed that urban participants were observed to have more healthy benefits associated with SEA; additional decreased prevalent hypertension and increased hypertension awareness associated with SEA were observed in wives and husbands respectively. Thus, SEA was associated with decreased prevalent hypertension and increased awareness and control of hypertension. Our findings call for increased participation of spouses in family-centered healthcare, with consideration of modified effects by gender, age, and residency type, to improve chronic disease prevention and control including hypertension.
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Éxito Académico , Hipertensión , Humanos , Adulto , Prevalencia , Hipertensión/epidemiología , Escolaridad , ConcienciaciónRESUMEN
OBJECTIVE: Emerging evidence proves the importance of circular RNAs (circRNAs) in many tumors, including breast cancer (BC). Here, we aimed to define a mechanism by which circ_0038632 regulates BC process. METHODS: To quantify the expression of circ_0038632, miR-520a-3p and cell division cycle associated 3 (CDCA3), a quantitative real-time PCR or immunoblotting method was utilized. The relationships of circ_0038632/miR-520a-3p and miR-520a-3p/CDCA3 in BC cells were determined using RNA immunoprecipitation (RIP) experiment and luciferase reporter assay. The effects of the circ_0038632/miR-520a-3p/CDCA3 cascade on cell biological phenotypes in vitro were examined by flow cytometry, EdU assay, cell counting kit 8 assay, transwell assay and wound healing assay. The function of circ_0038632 in tumorigenicity of BC cells in vivo was evaluated by xenograft experiments. RESULTS: Circ_0038632 and CDCA3 were highly expressed and miR-520a-3p expression was hindered in human BC. Depletion of circ_0038632 weakened cell growth, motility, and invasiveness while promoted cell apoptosis. In terms of mechanism, miR-520a-3p targeted CDCA3, and circ_0038632 involved the post-transcriptional modulation of CDCA3 expression by working as a miR-520a-3p sponge. Silencing of miR-520a-3p could reverse the inhibitory functions of circ_0038632 depletion in BC cell malignant phenotypes. Re-expression of CDCA3 also overturned the suppressive effects of miR-520a-3p on BC cell malignant phenotypes. In addition, circ_0038632 depletion inhibited the growth of xenograft tumors in vivo. CONCLUSION: Taken together, circ_0038632 promotes breast carcinogenesis through the miR-520a-3p/CDCA3 regulatory cascade, indicating that circ_0038632 may be a potential target for BC treatment.
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Neoplasias de la Mama , MicroARNs , Femenino , Humanos , Apoptosis/genética , Bioensayo , Neoplasias de la Mama/genética , Proteínas de Ciclo Celular/genética , MicroARNs/genética , Regiones Promotoras Genéticas , ARN Circular/genéticaRESUMEN
Acidic tea (Camellia sinensis) plantation soil usually suffers from magnesium (Mg) deficiency, and as such, application of fertilizer containing Mg can substantially increase tea quality by enhancing the accumulation of nitrogen (N)-containing chemicals such as amino acids in young tea shoots. However, the molecular mechanisms underlying the promoting effects of Mg on N assimilation in tea plants remain unclear. Here, both hydroponic and field experiments were conducted to analyze N, Mg, metabolite contents, and gene expression patterns in tea plants. We found that N and amino acids accumulated in tea plant roots under Mg deficiency, while metabolism of N was enhanced by Mg supplementation, especially under a low N fertilizer regime. 15N tracing experiments demonstrated that assimilation of N was induced in tea roots following Mg application. Furthermore, weighted gene correlation network analysis (WGCNA) analysis of RNA-seq data suggested that genes encoding glutamine synthetase isozymes (CsGSs), key enzymes regulating N assimilation, were markedly regulated by Mg treatment. Overexpression of CsGS1.1 in Arabidopsis (Arabidopsis thaliana) resulted in a more tolerant phenotype under Mg deficiency and increased N assimilation. These results validate our suggestion that Mg transcriptionally regulates CsGS1.1 during the enhanced assimilation of N in tea plant. Moreover, results of a field experiment demonstrated that high Mg and low N had positive effects on tea quality. This study deepens our understanding of the molecular mechanisms underlying the interactive effects of Mg and N in tea plants while also providing both genetic and agronomic tools for future improvement of tea production.
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Camellia sinensis , Camellia sinensis/genética , Camellia sinensis/metabolismo , Magnesio/metabolismo , Glutamato-Amoníaco Ligasa/genética , Glutamato-Amoníaco Ligasa/metabolismo , Nitrógeno/metabolismo , Fertilizantes , Aminoácidos/metabolismo , Té/metabolismo , Hojas de la Planta/metabolismo , Proteínas de Plantas/metabolismoRESUMEN
To provide guidance for the safe use of organic fertilizers and improve soil quality and tea safety, it is necessary to conduct systematic analyses of the heavy metal content of organic fertilizers applied in the main tea producing areas of China. In this study, we analyzed the heavy metal contents in organic fertilizer samples collected from 2017 to 2019. The risks of collected organic fertilizers from different areas and sources were calculated. The results showed that the average concentrations of ω(As), ω(Hg), ω(Pb), ω(Cd), ω(Cr), ω(Cu), ω(Zn), and ω(Ni) in the collected organic fertilizers were 4.60, 0.22, 27.1, 0.78, 27.9, 58.3, 250.1, and 16.3 mg·kg-1, respectively. According to the assessment standard in NY/T 525- 2021, the over-limit rates of As, Hg, Pb, Cd, and Cr were 6.19%, 1.33%, 4.42%, 4.42%, and 1.33%, respectively. With respect to the area, the qualified rates were 100% in Shaanxi, Jiangsu, Anhui, Fujian, and Guangxi; 80%-90% in Shandong, Zhejiang, Hubei, Sichuan, Yunnan, and Guangdong; and only 54.5% in Jiangxi. The qualified rates of sources were 100% in rapeseed cake, soybean cake, and pig manure; 95.8% in sheep manure; 91.7% in cow manure; 90.7% in chicken manure; 87.2% in manure of other animals; 82.4% in the mixture of plant and animal sources; 65.2% in other plant sources; and 63.6% in other sources. According to the recommended application rate, the accumulation rate of heavy metals in soil with pig manure, cow manure, chicken manure, and sheep manure would be much higher than that with rapeseed cake and soybean cake. The average accumulation rate of organic fertilizer from animal sources was 7-30 times higher than that from plant sources. Therefore, it is recommended to use rapeseed cake or soybean cake fertilizer in tea plantation and to increase the supervision of heavy metal accumulation in soil and tea in those high-risk areas.
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Brassica napus , Brassica rapa , Fabaceae , Mercurio , Metales Pesados , Contaminantes del Suelo , Animales , Cadmio/análisis , Pollos , China , Monitoreo del Ambiente/métodos , Fertilizantes/análisis , Plomo/análisis , Estiércol/análisis , Mercurio/análisis , Metales Pesados/análisis , Ovinos , Suelo , Contaminantes del Suelo/análisis , Glycine max , Porcinos , TéRESUMEN
Albino tea plants (Camellia sinensis) have been reported to possess highly inhibited metabolism of flavonoids compared to regular green tea leaves, which improves the quality of the tea made from these leaves. However, the mechanisms underlying the metabolism of catechins and flavonols in albino tea leaves have not been well elucidated. In this study, we analyzed a time series of leaf samples in the greening process from albino to green in a thermosensitive leaf-color tea mutant using metabolomics and transcriptomics. The total content of polyphenols dramatically decreased, while flavonols (such as rutin) were highly accumulated in albino leaves compared to in green leaves. After treatment with increasing environment temperature, total polyphenols and catechins were increased in albino mutant tea leaves; however, flavonols (especially ortho-dihydroxylated B-rings such as rutin) were decreased. Meanwhile, weighted gene co-expression network analysis of RNA-seq data suggested that the accumulation of flavonols was highly correlated with genes related to reactive oxygen species scavenging. Histochemical localization further demonstrated that this specific accumulation of flavonols might be related to their biological functions in stress tolerance. These findings suggest that the temperature-stimulated accumulation of total polyphenols and catechins in albino mutant tea leaves was highly induced by enhanced photosynthesis and accumulation of its products, while the initial accumulation and temperature inhibition of flavonols in albino mutant tea leaves were associated with metabolism related to oxidative stress. In conclusion, our results indicate that the biosynthesis of flavonoids could be driven by many different factors, including antioxidation and carbon skeleton storage, under favorable and unfavorable circumstances, respectively. This work provides new insights into the drivers of flavonoid biosynthesis in albino tea leaves, which will further help to increase tea quality by improving cultivation measures.
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Camellia sinensis , Catequina , Camellia sinensis/química , Carbono/metabolismo , Catequina/química , Flavonoides/análisis , Flavonoles/análisis , Metabolómica , Hojas de la Planta/química , Proteínas de Plantas/metabolismo , Polifenoles/análisis , Especies Reactivas de Oxígeno/metabolismo , Rutina/análisis , Té/genética , Té/metabolismo , TranscriptomaRESUMEN
To reveal the mechanisms underlying how light affects flavonoid metabolism and the potential role of flavonoids in protecting against photooxidative stress in tea leaves, tea plants adapted to low-light conditions were exposed to full sunlight over 48 h. There was an increase in the activities of catalase (CAT) and superoxide dismutase (SOD) as well as greater accumulation of reactive oxygen species, lutein, tocopherols, ascorbate and malondialdehyde, suggestive of a time-dependent response to photooxidative stress in tea leaves. Analysis of the time dependency of each element of the antioxidant system indicated that carotenoids and tocopherols exhibited the fastest response to light stress (within 3 h), followed by SOD, CAT and catechin, which peaked at 24 h. Meanwhile, flavonols, vitamin C and glutathione showed the slowest response. Subsequent identification of the main phytochemicals involved in protecting against oxidative stress using untargeted metabolomics revealed a fast and initial accumulation of nonesterified catechins that preceded the increase in flavonol glycosides and catechin esters. Gene expression analysis suggested that the light-induced accumulation of flavonoids was highly associated with the gene encoding flavonol synthase. Ultraviolet B (UV-B) irradiation further validated the time-dependent and collaborative effects of flavonoids in photoprotection in tea plants. Intriguingly, the dynamics of the metabolic response are highly distinct from those reported for Arabidopsis, suggesting that the response to light stress is not conserved across plants. This study additionally provides new insights into the functional role of flavonoids in preventing photooxidative stress and may contribute to further improving tea quality through the control of light intensity.
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Arabidopsis , Camellia sinensis , Catequina , Flavonoides/metabolismo , Antioxidantes/metabolismo , Catequina/metabolismo , Luz Solar , Hojas de la Planta/metabolismo , Camellia sinensis/metabolismo , Arabidopsis/metabolismo , Té/metabolismo , Tocoferoles/metabolismo , Superóxido Dismutasa/metabolismoRESUMEN
The quality of tea product and the metabolism of quality-related compounds in young shoots are significantly affected by the nitrogen(N) supply. However, little is known of the metabolic changes that take place in tea roots and mature leaves under different supplies, which has a large effect on the accumulation of quality-related compounds in young shoots. In this study, young shoots, mature leaves, and roots under different N conditions were subjected to metabolite profiling using gas chromatography and ultraperformance liquid chromatography, coupled with quadrupole time-of-flight mass spectrometry. The contents of free amino acids (e.g., theanine and glutamate) involved in N metabolism were significantly greater under high N than under low N, while a high N supply reduced soluble sugars (e.g., glucose) in all three tissues. Organic acids (e.g., malate, fumarate, α-ketoglutatare, and succinate) involved in tricarboxylic acid cycle remarkably increased as the nitrogen supply increased, which confirms that carbon (C) allocation was restricted by increasing the nitrogen supply, especially in mature leaves. RT-PCR results indicated that gene expression related to nitrogen assimilation significantly increased in roots with increasing nitrogen supply, which had a significant positive relationship with the level of free amino acids in young shoots. In addition, the expression of most genes involved in flavonoid synthesis was significantly upregulated under conditions of low nitrogen supply relative to high nitrogen supply in young shoot and roots. These data suggest that enhanced assimilation of N in tea roots and the coordinated regulation of C (sugars, organic acids, and flavonoids) and N(amino acids) in mature leaves can lead to a high accumulation of amino acids in young shoots. Furthermore, as the N supply increased, more C was partitioned into compounds containing N in mature leaves and roots, resulting in a decrease in flavonoids in young shoots. In conclusion, the accumulation of amino acids and flavonoids in young tea shoots is highly correlated with carbon and nitrogen metabolism in roots and mature leaves.
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Over 30% of the Chinese tea plantation is supplied with excess fertilizer, especially nitrogen (N) fertilizer. Whether or not foliar N application on tea plants at the dormancy stage could improve the quality of spring tea and be a complementary strategy to reduce soil fertilization level remains unclear. In this study, the effects of foliar N application on tea plants were investigated by testing the types of fertilizers and their application times, and by applying foliar N under a reduced soil fertilization level using field and 15N-labeling pot experiments. Results showed that the foliar N application of amino acid liquid fertilizer two times at the winter dormancy stage was enough to significantly increase the N concentration of the mature leaves and improved the quality of spring tea. The foliar application of 2% urea or liquid amino acid fertilizer two times at the winter dormancy stage and two times at the spring dormancy stage showed the best performance in tea plants among the other foliar N fertilization methods, as it reduced the soil fertilization levels in tea plantations without decreasing the total N concentration of the mature leaves or deteriorating the quality of spring tea. Therefore, foliar N application on tea plants at its dormancy stage increases the N concentration of the mature leaves, improves the quality and yield of spring tea, and could be a complementary strategy to reduce soil fertilization levels.
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Metabolites are major contributors to the quality of tea that are regulated by various abiotic stresses. Light intensity and phosphorus (P) supply affect the metabolism of tea plants. However, how these two factors interact and mediate the metabolite levels in tea plants are not fully understood. The present study investigated the consequences of different light intensity and P regimes on the metabolism of carbohydrates, amino acids, and flavonoids in the Fengqing tea cultivar. The leaves and young shoots were subjected to untargeted metabolomics analysis by two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC×GC-TOF/MS), ultra-performance liquid chromatography-quadrupole-TOF/MS (UPLC-Q-TOF/MS), and targeted analysis by high-performance liquid chromatography (HPLC) along with quantification of gene expression by quantitative real time-PCR (qRT-PCR). The results from young shoots showed that amino acids, pentose phosphate, and flavonol glycosides pathways were enhanced in response to decreasing light intensities and P deficiency. The expression of the genes hexokinase 1, ribose 5-phosphate isomerase A (RPIA), glutamate synthetase 1 (GS1), prolyl 4-hydroxylase (P4H), and arginase was induced by P limitation, thereafter affecting carbohydrates and amino acids metabolism, where shading modulated the responses of transcripts and corresponding metabolites caused by P deficiency. P deprivation repressed the expression of Pi transport, stress, sensing, and signaling (SPX2) and induced bidirectional sugar transporter (SWEET3) and amino acid permeases (AAP) which ultimately caused an increase in the amino acids: glutamate (Glu), proline (Pro), and arginine (Arg) under shading but decreased catechins [epicatechingallate (ECG) and Gallic acid, GA] content in young shoots.
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Glutamate dehydrogenase (GDH) is a central enzyme in nitrogen metabolism, assimilating ammonia into glutamine or deaminating glutamate into α-oxoglutarate. Tea (Camellia sinensis L.) plants assimilate ammonium efficiently, but the role of CsGDH in ammonium assimilation remains unclear. We confirmed that tea has three GDH isogenes: CsGDH1-3. Bioinformatic analysis showed that CsGDH1 encodes the ß-GDH subunit, CsGDH2/3 encode the α-GDH subunit, and their proteins all feature an NADH-specific motif. CsGDH1 is mainly expressed in mature leaves and roots, CsGDH3 is mainly expressed in new shoots and roots, and CsGDH2 has the highest expression level in flowers compared to the other five tissues. Expression patterns of CsGDHs and glutamine synthetase isogenes (CsGSs) under different ammonium concentrations suggested that CsGDHs cooperate with CsGSs to assimilate ammonium, especially under high ammonium conditions. Inhibition of GS and its isogenes resulted in significant induction of CsGDH3 in roots and CsGDH2 in leaves, indicating their potential roles in ammonium assimilation. Moreover, CsGDHs transcripts were highly abundant in chlorotic tea leaves, in constrast to those of CsGSs, suggesting that CsGDHs play a vital role in ammonium assimilation in chlorotic tea mutant. Altogether, our circumstantial evidence that CsGDHs cooperate with CsGSs in ammonium assimilation provides a basis for unveiling their functions in tea plants.
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Compuestos de Amonio/metabolismo , Camellia sinensis/genética , Camellia sinensis/metabolismo , Glutamato Deshidrogenasa/genética , Glutamato Deshidrogenasa/metabolismo , Glutamato-Amoníaco Ligasa/genética , Glutamato-Amoníaco Ligasa/metabolismo , Productos Agrícolas/genética , Productos Agrícolas/metabolismo , Flores/metabolismo , Regulación de la Expresión Génica de las Plantas , Genes de Plantas , Isoenzimas/genética , Isoenzimas/metabolismo , Hojas de la Planta/metabolismo , Raíces de Plantas/metabolismo , Brotes de la Planta/metabolismoRESUMEN
Background and Aims: Magnesium (Mg) fertilizer has been proved to play an important role in improving the yield and quality of tea. However, plant availability of Mg, including its use, efficiency, and quality improvement effects, were highly affected by plant species, soil characteristics (nutritional status, etc.), and Mg status (chemical-available, etc.). Methods: Tea plants were pot-cultivated in 12 typical tea plantation soils amended with and without Mg fertilizer. Exchangeable Mg (Ex-Mg) concentration in soils was quantitatively extracted using four extraction solutions (Mehlich-3, BaCl2, CaCl2, and NH4OAC). Plant availability of Mg was evaluated by Mg uptake and its use efficiency, as well as its association with quality components in tea plants. Results: Ex-Mg in soils was extracted most efficiently by Mehlich-3, while Mg concentrations in tea plant tissue were higher correlated with Ex-Mg extracted by CaCl2 than other extraction solutions. Mg fertilizer use efficiency in tea plant varied from 6.08 to 29.56 %, and the effect of Mg application on tea quality improvement and the use efficiency of Mg fertilizer both negatively correlated with total Mg concentration (r = -0.94 and -0.63, respectively) and nitrogen (N) level (r = -0.61 and -0.51, respectively) in soils prior to tea plant cultivation. Conclusions: CaCl2 could be recommended for plant-available Mg extraction in tea plantation soil, and Mg fertilizer use efficiency could be affected and predicted by total N and Mg status in soils prior to tea plant cultivation, providing a potential theoretical for the guidance of Mg fertilization for tea yield and quality improvement in tea plantation management.
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It is well known that green tea made from fully developed leaves located at the base of young shoots is of lower quality than that made from the still developing leaves located on the top of the shoot. It has additionally been shown that plant shading can significantly improve green tea quality. Here, we aimed to get more insight into the effects of shading on the overall metabolome in different parts of the tea shoots. To do this, field-grown tea plants were shaded by coverage with either a straw layer or a black net, both blocking the daylight intensity for more than 90%. Both the first (i.e. still developing) leaf and the fourth (i.e. fully developed) leaf, as well as the stem of young shoots were harvested and subjected to complementary untargeted metabolomics approaches, using accurate mass LC-Orbitrap-Fourier transform mass spectrometry (FTMS) for profiling both semi-polar and lipid-soluble compounds and GC-TOF-MS for profiling polar compounds. In total, 1419 metabolites were detected. Shading resulted in a decreased ratio of polyphenols to amino acids (which improves the quality of green tea) and lower levels of galloylated catechins in the shoots. The positive effect of shading on the amino acid/catechin ratio was more pronounced in the fully developed (fourth) than in the developing (first) leaves. Furthermore, many metabolites, especially organic acids, carbohydrates and amino acids, showed differential or opposite responses to the shading treatments between the three shoot tissues investigated, suggesting a within-plant spatial regulation or transport/redistribution of carbon and nitrogen resources between the tissues of the growing young shoots. This work provides new insight into the spatial effects of shading on tea plants, which could further help to increase tea quality by improving cultivation measures for plant shading.
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Camellia sinensis , Catequina , Catequina/análisis , Metabolómica , Hojas de la Planta/química , TéRESUMEN
Tea plant (Camellia sinensis) is an ammonium preferring plant species. However, little is known about the mechanism underlying this preference. Herein, a chloroplastic glutamine synthetase gene (CsGS2), which is vital for nitrogen assimilation in mesophyll tissue, was isolated from tea cultivar C. sinensis cv. 'Longjing43'. The full length cDNA of CsGS2 was 1622 bp, having a 1299 bp open reading frame encoding a 432-amino acid protein. Homology search and sequence analysis demonstrated that CsGS2 protein carried the basic characteristics of a canonical GS2 domain and shared high identity with GS2s from other plant species. Subcellular localization and immunolocalization of CsGS2 revealed that it is localized in chloroplast. qRT-PCR and Western blot analyses showed that CsGS2 was expressed in a leaf-specific pattern, such that both CsGS2 and its protein were most abundant in mature leaves. Temporal expression patterns of CsGS2 showed minor differences in response to ammonium and nitrate nutrition. The transcript level of CsGS2 was significantly induced in mature leaves during the development of new shoots, whereas darkness inhibited this induction significantly. These results suggested that CsGS2 does not play a role in the differential utilization mechanisms of differing nitrogen forms in tea, and imply a light dependent transcription regulation in mature leaves during the development of new shoots.
Asunto(s)
Camellia sinensis/enzimología , Glutamato-Amoníaco Ligasa/genética , Proteínas de Plantas/genética , Camellia sinensis/genética , Regulación de la Expresión Génica de las Plantas , Hojas de la Planta/enzimologíaRESUMEN
Physiological effects of ammonium (NH4+) and nitrate (NO3-) on tea have confirmed that tea plants prefer NH4+ as the dominant nitrogen (N) source. To investigate the possible explanations for this preference, studies of 15NH4+ and 15NO3- assimilation using hydroponically grown tea plants were conducted. During the time course of 15NH4+ and 15NO3- assimilation, the absorption of 15N from 15NH4+ was more rapid than that from 15NO3-, as there was a more efficient expression pattern of NH4+ transporters compared with that of NO3- transporters. 15NH4+-fed tea plants accumulated more 15N than 15NO3- fed plants, which was demonstrated by that genes related to primary N assimilation, like CsNR, CsNiR, CsGDH and CsGOGAT, were more affected by 15NH4+ than 15NO3-. Markedly higher NH4+ concentrations were observed in 15NH4+-fed tea roots in comparison with NO3- treatment, whereas tea plants maintained a balanced concentration of NH4+ in tea leaves under both these two N forms. This maintenance was achieved through the increased expression of genes involved in theanine biosynthesis and the inhibition of genes related to catechins derived from phenylpropanoid pathway. The current results suggest that efficient NH4+ transportation, assimilation, and reutilization enables tea plant as an ammonium preferring plant species.
Asunto(s)
Compuestos de Amonio/metabolismo , Camellia sinensis/metabolismo , Catequina/biosíntesis , Genes de Plantas , Nitratos/metabolismo , Nitrógeno/metabolismo , Transporte Biológico , Camellia sinensis/genética , Catequina/genéticaRESUMEN
BACKGROUND: Greater proportions of purple tea buds and leaves usually appear in the summer, which seriously affects the color and taste quality of green tea products, yet the metabolism of purple tea shoots in summer remains unclear. Here, the metabolomic profiles and gene expression of related flavonoid metabolic pathways in the purple and normal green shoots of 'Longjing 43', and the quality of green tea made with these two phenotypes, were analyzed and compared. RESULTS: Differential metabolites identified using high-performance liquid chromatography-Orbitrap/mass spectrometry indicated that anthocyanin biosynthesis in purple leaves was enriched, with higher levels of anthocyanidins (delphinidin-hexose-coumaroyl showed the greatest increase), proanthocyanidins (oligomers of catechins) and kaempferol glycoside. Expression patterns of the genes ANR, ANS, FLS, LAR, C4H, PAL, CHI, CHS and DFR revealed that the metabolism of anthocyanin is positively regulated by high temperature and/or light levels in summer. Gas chromatography-mass spectrometry results showed that, in purple tea shoots, the metabolism of carbohydrates was enriched whereas that of amino acids was diminished, while their mannose, fructose, d-galactose, sorbose and d-glucose contents were more than double those found in green leaves. A sensory evaluation confirmed that a greater quantity of purple shoots had a greater negative impact on green tea quality because of a bitter taste and dark color (leaves and infusions were tested). CONCLUSIONS: These results highlight the need for and possibility of improving commercial tea quality via cultivation that controls the temperature or light of tea gardens during the summer. © 2019 Society of Chemical Industry.