Journal of Tea Science

Influence of Amino Acid Foliar Application on the Amount of γ-Aminobutyric Acid in Tea Leaf

ZHANG Ding, TANG Cha-Qin, CHEN Xuan, XU De-liang, XIAO Run-lin, LI Xing-hui

Journal of Tea Science. 2006, 26(4): 237-242. doi:10.13305/j.cnki.jts.2006.04.001

Abstract ( 620 )

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Vacuum and anaerobic treated fresh tea leaves which sprayed by different kind or concentration of amino acid were investigation. The influence on theγ-aminobutyric acid (GABA) biosynthesis by different treatments were analyzed. The result showed that the content ofγ-aminobutyric acid was enhanced obviously after foliage-sprayed and vacuum treatment. The influence of six types of amino acid on the ability ofγ-aminobutyric acid biosynthesis was Glutamic Acid>Asparticacid>Glutamine>Phenylalanine>Glycine>Alanine. The content of Glutamic acid, Aspartic acid and Thenine in tea fresh leaves may be the criterion of synthesizing ability forγ-aminobutyric acid. The total content of Glutamic acid, Aspartic acid and theanine has reached the peak on the fifth day in tea fresh leaves. 0.5% Glutamic acid sprayed on tea leaves for 5 days is the best method.

Construction of Tea Caffeine Synthase Gene RNAi Vector

ZHANG Guang-hui, LIANG Yue-rong, LU Jian-liang, DONG Jun-jie

Journal of Tea Science. 2006, 26(4): 243-248. doi:10.13305/j.cnki.jts.2006.04.002

Abstract ( 654 )

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Tea Caffeine synthase (TCS) is one of the key enzymes involved in caffieine biosynthsis in tea plant (Camellia sinensis),which catalyses conversions of 7-methylxanthine to theobromine and theobromine to caffeine. Inhibition of TCS gene expression can leads to breeding low caffeine tea cultivars. Two cDNA fragments of TCS gene were amplified by RT-PCR, and ligated into T-vector. The two TCS gene fragments were inserted into RNAi vector pFGC5941 in reverse direction after double digestion with two pairs of restriction endonucleases. The insertion of two fragments, namely pFGC5941-TCS02 and pFGC5941-TCS03, into the RNAi vector were confirmed by PCR and DNA sequencing.

AFLP Analysis of Genetic Diversity of Tea plant Germplasms in Guangdong Province

ZHAO Chao-yi, LUO Jun-wu, HUANG Jian-an, TAN He-ping

Journal of Tea Science. 2006, 26(4): 249-252. doi:10.13305/j.cnki.jts.2006.04.003

Abstract ( 415 )

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Based on AFLP method, AFLP figure were obtained in Guangdong tea plants. In this study, totally 365 bands were amplified by 5 pairs of primes and 73 bands were amplified by each primer pair on average, a total of 338 (92.6%) polymorphic AFLP markers were detected. The results indicated that the genetic distance (GD) based on AFLP data by using DPS 2000 was significant. The GD(0.5) is highest between Guibeidaye and Fenghuangshuixian, but the GD(0.12752) between Qingliangshan tea and Qingyuanbijia tea is low. This indicated that the Guangdong tea plant has a high genetic diversity.

The Use of Diversity of Tea Cultivars for Bud Blight Control

ZHANG Ze-cen WANG Xue-ping

Journal of Tea Science. 2006, 26(4): 253-258. doi:10.13305/j.cnki.jts.2006.04.004

Abstract ( 435 )

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Field experiments of mixed and single-cultivar-planting of 6 susceptible cultivars and 3 tea bud blight-resistant cultivars, and the genetic diversity, and the relationship of 10 tea cultivars were investigated by RAPD. The results demonstrated that 10 tested tea cultivars can be classified into 2 complex groups and 3 simple groups, a total of 110 polymorphic DNA bands were amplified (89.43%). The disease incidence infected leaf-area percentage disease index and infected leaf area in the mixed planting plots were significantly lower than those in the single-cultivar-planting plots. The susceptible cultivars showed significant greater decreasing range the control efficiency gained 28.54%~73.77%. It suggests that inter-planting of tea cultivars with different genetic background and morphological characteristic is an effective approach for tea bud blight control.

Mechanism of the Control of Tea Grey Blight Disease by Bacillus subtilis Strain TL2

HONG Yong-cong, LAI Yu-bin, YE Wen-na, LIN Pei-xian, HU Fang-ping

Journal of Tea Science. 2006, 26(4): 259-264. doi:10.13305/j.cnki.jts.2006.04.005

Abstract ( 345 )

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The antifungal proteins secreted by Bacillus subtilis strain TL2 were tested and showed a good inhibitive effect on the mycelial growth and the conidia germination of Pestalotiopsis theae. It was also found that when strain TL2 was inoculated, the SOD activity in tea plant were obviously changed to depress the generating speed of superoxide anion in tea plant, also the PAL activity and β-1,3-glucanases activity in tea plant were quickly increased to restrain the expansion of P. theae.

The Pathogenicity of Euproctis Pseudoconspersa Nuclear Polyhedrosis Virus on the Larvae of Tea Tussork (Euproctis pseudoconspersa Strand)

LI Xiao-la, JIN Yi-wei, CHAI Yi-qiu, CHEN Guan-ju, LIU You-gao

Journal of Tea Science. 2006, 26(4): 265-269. doi:10.13305/j.cnki.jts.2006.04.006

Abstract ( 496 )

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The reproduction, extraction, pathogenicity to Tea Tussork Moth and electron micrograph testing of Euproctis pseudoconspersa Nuclear Polyhedrosis Virus(EpNPV) was investigated. The EpNPV was propagated through Inoculating 2~3 instar larvae of Euproctis pseudoconspersa, by raged with EpNPV at the concentration 10⁶βPIB/ml, or inoculating 2~3 instar larvae in field condition. Inoculation the larvae with 10⁶βPIB/ml, 10⁷βPIB/ml, and 10⁸βPIB/ml of EpNPV, the corrected mortalities were 43.60％, 76.13％ and 64.68％ on day 12 respectively, and reached 59.17％, 95.71％, and 95.70％ on day 14 respectively. The mortality was 78.11% on day 15 treated with EpNPV(10⁷βPIB/ml) under field condition. Virus of the EpNPV from the field dead larvae could be watched through the electron microscope.

Colonization of Bacillus subtilis Strain TL2 in Tea Plant

HONG Yong-cong, FAN Xiao-jing, LAI Yu-bin, HU Fang-ping

Journal of Tea Science. 2006, 26(4): 270-274. doi:10.13305/j.cnki.jts.2006.04.007

Abstract ( 416 )

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Bacillus subtilis Strain TL2 was proved to be able to colonize in different tissues inside the tea plant, and the community quality and diversity index of the endophytic bacteria were both decreased in tea plant with the time after inoculated. The bacteri of strain TL2 were found to be mainly distributed in the intercellular space of sclerenchyma in the root, the intercellular space of collenchyma and vascular bundle in the stem, the stomatal apparatus, the intercellular space of epidermal cell, collenchyma and endodermis in the leaf.

Experimental study on Microencapsulation of Tea Polyphenols

MENG Xiang, LI Bao-guo

Journal of Tea Science. 2006, 26(4): 275-279. doi:10.13305/j.cnki.jts.2006.04.008

Abstract ( 509 )

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To explore the new method of preparing slow-releasing microspheres of tea polyphenols, which will be useful for the applications of tea polyphenols. Through spray drying technology, tea polyphenols were microencapsulated by hydroxypropyl methylcellulose phthalate which is a biodegradable material. The microencapsulation process of tea polyphenols was optimized with orthogonal design L₉(3⁴), the retention of tea polyphenols microspheres was used as the index. Results: A little emulsifier could increase the retention greatly , and the efficiency of SDS was better than PVA. The optimized conditions of tea polyphenols microencapsulation were that entrance temperature was 100℃, entrance speed was 6.25βml/min, proportion of tea polyphenols and wall material was 2:1, proportion of all solid maters was 3%. Using Hydroxypropyl methylcellulose phthalate as the wall material is feasible to prepare tea polyphenols microspheres by spray drying technology, and tea polyphenols microspheres had a slow-releasing efficiency.

Separation and Quantitation of Theanine Enantiomers on Ligand Exchange Chromatography with Chiral Mobile Phase

LI Yin-hua, LIU Zhong-hua, HUANG Jian-an

Journal of Tea Science. 2006, 26(4): 280-284. doi:10.13305/j.cnki.jts.2006.04.009

Abstract ( 442 )

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Ligand exchange chromatography with chiral mobile phases was established for the separation of theanine enantiomers.The optimum condition was :Polaris C₁₈column, mobile phase: L-proline: Cu²⁺=2:1, the concentration of Cu²⁺was 0.5βmmol/L, pH6.8, the volume of methanol is 2%, wavelength: 254βnm;flow rate:0.9βml/min, column temperature:30℃. There was a good linearity between peak areas and injection quantities of L-Theanine ranging from 0.09542βμg~4.241βμg and D-Theanine ranging from 0.08486βμg~4.243βμg. The recovery of L-Theanine range from 97.45%~100.4% and D-Theanine range from 97.07%~100.1%.

Study on the Optimum Condition of Synthesizing Theaflavins by Using Enzyme-catalysing Oxidation

GU Ji-ping, LIU Zhong-hua, HUANG Jian-an, SHI Zhao-peng

Journal of Tea Science. 2006, 26(4): 285-290. doi:10.13305/j.cnki.jts.2006.04.010

Abstract ( 479 )

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Obtain the optimum reaction condition of synthesizing theaflavins by enzymatic oxidation, synthesizing theaflavins was studied by raw ppo extracted from fresh tea leaves under single factor and orthogonal experimental design. Based on these results, synthesizing theaflavins was also studied by using breaking fresh tea leaves. The result showed that the optimum condition of theaflavins synthesizing is 30℃ temperature is, under this reaction system, pH value of the present system is 4.8, the concentration of substrates is 0.9βg/100βml, the concentration of enzymes is 28βg/100βml (based on the fresh weight), oxygen rate is 0.4βL/min. Temperatures and pH values in the reaction system are the most important factors(P<0.05), and adding suitable oxygen is another necessary factor in theaflavins synthesis by enzymatic oxidation.

Extraction of Tea-polyphenols from Tea Leaves by Ultrahigh Pressure Technique

ZHANG Ge, ZHANG Ling-ling, WU Hua, ZHANG Shou-qin

Journal of Tea Science. 2006, 26(4): 291-294. doi:10.13305/j.cnki.jts.2006.04.011

Abstract ( 605 )

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The extactrion of tea-polyphenols from tea leaves by using the ultrahigh pressure extraction technology (UPE) was studied. The experiment was designed with orthogonal method, and the yield of tea-polyphenols is used as the testing index. The extract conditions, including of the solvent concentration, pressure, the holding time of pressure and the soaking time before extraction, were investigated. The optimum extraction conditions are as follow, 60% ethanol, 200βMPa holding 3βmin., soaking 0.5 hr. The yield of tea-polyphenols is 28.92% under the optimum extraction condition. After separation, the yield of crude product of tea extraction is higher 25.3% than that of heat reflux method and the total of tea-polyphenols is higher 32% than that of heat reflux method. In addition, the extraction liquid of UPE is clear, easily to filter and no turbid after stored a long time. As a new extraction technology, UPE showed the great economic benefit if applied to extract tea-ployphenols from tea leaves in industrial scale.

Study on the Inhibition of Mixture of Tea-Polyphenol and Vitamin C on Helicobacter Pylori

XIAO Bo, QU Hui-ge, HUANG Qing-rong, YU Chuan-chuan, ZHAO Bo

Journal of Tea Science. 2006, 26(4): 295-298. doi:10.13305/j.cnki.jts.2006.04.012

Abstract ( 705 )

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The mixture of tea-polyphenol (TP) and vitamin C(VC) with various concentrations were interfused into the liquid medium, then the inhibitive effect of the mixture on Helicobacter Pylori was determined in vitro. The result indicates that the inhibitive effect of the mixed solution of tea-polyphenol and vitamin C is more efficient than that of individuals, separately. The strongest inhibition is 98.23% when the concentration of mixture is TP 1.2βmg/ml, VC 0.08βmg/ml.

Effects of Atmospheric CO₂ Concentration on Tea Quality

JIANG Yue-lin, ZHANG Qing-guo, ZHANG Shi-ding

Journal of Tea Science. 2006, 26(4): 299-304. doi:10.13305/j.cnki.jts.2006.04.013

Abstract ( 508 )

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The quality components including amino acids, polyphenols, caffeine, soluble sacchrides and main nutrient elements in tea were measured under ambient and elevated CO₂ conditions, and effects of elevated atmospheric CO₂ concentration on tea quality were analysed. The results showed that amino acid contents in tea decreased by 1.7%~4.5% and 6.7%~12.2% under elevated (500 and 750βμmol/mol) CO₂, compared to the ambient air CO₂ concentration. At the same time, the caffeine contents reduced by 3.1%~4.6% and 5.1%~10.7%. The polyphenol contents increased by 3.8%~6.0% and 6.9%~11.3%. The solule sacchride contents increased by 8.4%~14.4% and 18.1%~28.2%. It was also found that the N, K, Ca, P and Na contents in tea decreased to some extent. The Zn, Mg and Fe contents increased with CO₂ enrichment.

Analysis of Theanine and Catechins in Hairy Roots of Camellia sinensis

ZHANG Guang-hui, LIANG Yue-rong, LU Jian-liang, DONG Jun-jie

Journal of Tea Science. 2006, 26(4): 305-309. doi:10.13305/j.cnki.jts.2006.04.014

Abstract ( 451 )

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Hairy roots induced by Agrobacterium rhizogenes wild strain 15834 were propagated on LG₀ medium and half MS medium containing 1βmg/L IBA to promote rapid growth. Although rapid growth was obtained in half MS media containing 1βmg/L IBA, high content of theanine (23.12βmg/g fresh weight) was only detected in one hairy root clone cultured on LG₀ medium and higher than the non-transformed root (18.77βmg/g fresh weight). High content of aspartic acid, glutamic acid, glutamine, histidine and arginine were also detected in this hairy root clones. Medium constitute also affected the contents of amino acid in hairy root clone, the content of theanine were reduced in two hairy root clones when they were cultivated on half MS with 1βmg/L IBA. Low content of simple catechins, catechin (C) and epicatechin (EC), were also detected in hairy roots.

Study on the Content of EGCG3"Me in Different Tea Germplasms and its Changes

LU Hai-peng, TAN Jun-feng, LIN Zhi

Journal of Tea Science. 2006, 26(4): 310-314. doi:10.13305/j.cnki.jts.2006.04.015

Abstract ( 412 )

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The changes of EGCG3"Me content in different tea germplasms, crop seasons and tea processing were studied by HPLC. The content of EGCG3"Me in six tested tea cultivars was more than 1% among 200 tea germplasms containing high tea polyphenols. The content of EGCG3"Me in new tea shoot was increased with the leaf maturity, and was higher in autumn tea than in summer tea. The content of EGCG3"Me was not changed obviously during the process of green tea manufacture, but increased distinctly during the withering process of the Oolong tea.

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