Positive Effects of the Tea Catechin, (−)-Epigallocatechin-3-Gallate, on Gut Prophenoloxidase and the Survival of Ectropis obliqua (Lepidoptera: Geometridae)

2019 ◽  
Vol 48 (5) ◽  
pp. 1173-1177
Author(s):  
Yanhua Long ◽  
Yong Zhang ◽  
Tianyu Zhao ◽  
Xiaomin Zhou ◽  
Yun Wang ◽  
...  

Abstract Ectropis obliqua Prout is the main pest of the tea plant Camellia sinensis (L.) O. Kuntze in China, affecting an annual area of more than one million acres. (−)-Epigallocatechin-3-gallate (EGCG) is the major catechin in tea leaves. Here, we show that EGCG is highly efficient in increasing the survival rate of E. obliqua larvae. We also compared the gut peroxidase (PO) activity between EGCG-fed and control larvae. EGCG-fed larvae had significantly greater PO activity levels than control larvae. Western blotting validated these results. Gut PO activity levels of larvae fed an artificial diet gradually decreased and disappeared completely by day 5. We hypothesize that the increased survival rate of EGCG-fed larvae was associated with increased PO activity. This research provides evidence that E. obliqua larvae have adapted to, and may even benefit from, secondary compounds found in tea leaves.

2015 ◽  
Vol 10 (5) ◽  
pp. 1934578X1501000 ◽  
Author(s):  
Wei-Wei Deng ◽  
Min Li ◽  
Chen-Chen Gu ◽  
Da-Xiang Li ◽  
Lin-Long Ma ◽  
...  

Caffeine, a purine alkaloid, is a major secondary metabolite in tea leaves. The demand for low caffeine tea is increasing in recent years, especially for health reasons. We report a novel grafted tea material with low caffeine content. The grafted tea plant had Camellia sinensis as scions and C. oleifera as stocks. The content of purine alkaloids was determined in the leaves of one-year-old grafted tea plants by HPLC. We also characterized caffeine synthase (CS), a key enzyme involved in caffeine biosynthesis in tea plants, at the expression level. The expression patterns of CS were examined in grafted and control leaves by Western blot, using a self-prepared polyclonal antibody with high specificity and sensitivity. The expression of related genes ( TCS1, tea caffeine synthase gene, GenBank accession No. AB031280; sAMS, SAM synthetase gene, AJ277206; TIDH, IMP dehydrogenase gene, EU106658) in the caffeine biosynthetic pathway was investigated by qRT-PCR. HPLC showed that the caffeine content was only 38% as compared with the non-grafted tea leaves. Immunoblotting analysis showed that CS protein decreased by half in the leaves of grafted tea plants. qRT-PCR revealed no significant changes in the expression of two genes in the upstream pathway ( sAMS and TIDH), while the expression of TCS1 was greatly decreased (50%). Taken together, these data revealed that the low caffeine content in the grafted tea leaves is due to low TCS1 expression and CS protein accumulation.


2020 ◽  
Vol 21 (16) ◽  
pp. 5684 ◽  
Author(s):  
Xiaochen Zhou ◽  
Lanting Zeng ◽  
Yingjuan Chen ◽  
Xuewen Wang ◽  
Yinyin Liao ◽  
...  

In tea (Camellia sinensis) plants, polyphenols are the representative metabolites and play important roles during their growth. Among tea polyphenols, catechins are extensively studied, while very little attention has been paid to other polyphenols such as gallic acid (GA) that occur in tea leaves with relatively high content. In this study, GA was able to be transformed into methyl gallate (MG), suggesting that GA is not only a precursor of catechins, but also can be transformed into other metabolites in tea plants. GA content in tea leaves was higher than MG content—regardless of the cultivar, plucking month or leaf position. These two metabolites occurred with higher amounts in tender leaves. Using nonaqueous fractionation techniques, it was found that GA and MG were abundantly accumulated in peroxisome. In addition, GA and MG were found to have strong antifungal activity against two main tea plant diseases, Colletotrichum camelliae and Pseudopestalotiopsis camelliae-sinensis. The information will advance our understanding on formation and biologic functions of polyphenols in tea plants and also provide a good reference for studying in vivo occurrence of specialized metabolites in economic plants.


Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3290
Author(s):  
Wei Li ◽  
Fen Xiang ◽  
Yi Su ◽  
Zhoufei Luo ◽  
Weigui Luo ◽  
...  

Tea (Camellia sinensis) is one of the most important cash crops in the world. Theanine, as an important amino acid component in tea, is a key quality index for excellent tea quality and high economic value. People increase theanine accumulation in tea mainly through the application of nitrogen fertilizer, shading and pruning. However, these methods are not effective. In this study, we treated tea buds with a 100 μM solution of GA3 containing 1‰ tween-20, investigated the effects of GA3 on theanine accumulation, bud yield, chlorophyll fluorescence parameters and expression level of theanine biosynthesis pathway genes in tea plant by qPCR, LC-MS/MS etc. Results showed that change trends of theanine and GA3 was extremely positively correlated with each other. Exogenous GA3 upregulated the expression level of theanine biosynthesis pathway genes, caused an increase of theanine content (mg·g-1) by 27% in tea leaves compared with Mock, and accelerated the germination of buds and elongation of shoots, which lead to a significant increase of tea yield by 56% (w/w). Moreover, the decrease of chlorophyll contents, photochemical quenching coefficient (qP) and relative electron transport rate (rETR) under GA3 treatment suggested that GA3 reduced photosynthesis in the tender tea leaves, indicating that the decline of carbon assimilation in tea plants was conducive to the nitrogen metabolism, and it was beneficial to the accumulation of theanine. This study provided a new technical and theoretical support for the precise control of tea quality components and phenophase.


2018 ◽  
Vol 44 (3) ◽  
pp. 463 ◽  
Author(s):  
Zhang PENG ◽  
Hua-Rong TONG ◽  
Guo-Lu LIANG ◽  
Yi-Qi SHI ◽  
Lian-Yu YUAN

2016 ◽  
Vol 42 (1) ◽  
pp. 58 ◽  
Author(s):  
Bo WANG ◽  
Hong-Li CAO ◽  
Yu-Ting HUANG ◽  
Yu-Rong HU ◽  
Wen-Jun QIAN ◽  
...  

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Seyed Taghi Heydari ◽  
Leila Zarei ◽  
Ahmad Kalateh Sadati ◽  
Najmeh Moradi ◽  
Maryam Akbari ◽  
...  

Abstract Background The COVID-19 outbreak is a global pandemic, during which the community preventive and protective behaviors play a crucial role in the containment and control of infection. This study was designed to contribute to the existing knowledge on how risk communication (RC) and risk perception (RP) affect protective and preventive behaviors (PPB) during the COVID-19 outbreak. Methods The required data were extracted from a national online survey of Iranian adults aged 15 and older during March 15–19, 2020 (n=3213). Data analysis was performed using structural equation modeling. Results The study findings reveal that RC has direct and indirect positive effects on PB. Furthermore, this study also provides new evidence indicating that RP mediates the relationship between RC and PB and there is a two-way relationship between RC and RP. These interactions may have impact on risk communication strategies which should be adopted during this pandemic. Conclusion The study findings have remarkable implications for informing future communications as well as interventions during this ongoing outbreak and subsequent national risk events.


2021 ◽  
Vol 28 ◽  
pp. 107327482199743
Author(s):  
Ke Chen ◽  
Xiao Wang ◽  
Liu Yang ◽  
Zheling Chen

Background: Treatment options for advanced gastric esophageal cancer are quite limited. Chemotherapy is unavoidable at certain stages, and research on targeted therapies has mostly failed. The advent of immunotherapy has brought hope for the treatment of advanced gastric esophageal cancer. The aim of the study was to analyze the safety of anti-PD-1/PD-L1 immunotherapy and the long-term survival of patients who were diagnosed as gastric esophageal cancer and received anti-PD-1/PD-L1 immunotherapy. Method: Studies on anti-PD-1/PD-L1 immunotherapy of advanced gastric esophageal cancer published before February 1, 2020 were searched online. The survival (e.g. 6-month overall survival, 12-month overall survival (OS), progression-free survival (PFS), objective response rates (ORR)) and adverse effects of immunotherapy were compared to that of control therapy (physician’s choice of therapy). Results: After screening 185 studies, 4 comparative cohort studies which reported the long-term survival of patients receiving immunotherapy were included. Compared to control group, the 12-month survival (OR = 1.67, 95% CI: 1.31 to 2.12, P < 0.0001) and 18-month survival (OR = 1.98, 95% CI: 1.39 to 2.81, P = 0.0001) were significantly longer in immunotherapy group. The 3-month survival rate (OR = 1.05, 95% CI: 0.36 to 3.06, P = 0.92) and 18-month survival rate (OR = 1.44, 95% CI: 0.98 to 2.12, P = 0.07) were not significantly different between immunotherapy group and control group. The ORR were not significantly different between immunotherapy group and control group (OR = 1.54, 95% CI: 0.65 to 3.66, P = 0.01). Meta-analysis pointed out that in the PD-L1 CPS ≥10 sub group population, the immunotherapy could obviously benefit the patients in tumor response rates (OR = 3.80, 95% CI: 1.89 to 7.61, P = 0.0002). Conclusion: For the treatment of advanced gastric esophageal cancer, the therapeutic efficacy of anti-PD-1/PD-L1 immunotherapy was superior to that of chemotherapy or palliative care.


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