Key Laboratory of Tea Science

Changsha, China

Key Laboratory of Tea Science

Changsha, China
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Xiong S.,Hunan Agricultural University | Tian N.,Hunan Agricultural University | Chen Y.,Hunan Agricultural University | Qin Y.,Hunan Agricultural University | And 4 more authors.
Plant Physiology and Biochemistry | Year: 2016

Flavonoids were found to synergize anti-malaria and anti-cancer compounds in Artemisia annua, a very important economic crop in China. In order to discover the regulation mechanism of flavonoids in Artemisia annua, the full length cDNA of flavanone 3-hydroxylase (F3H) were isolated from Artemisia annua for the first time by using RACE (rapid amplification of cDNA ends). The completed open read frame of AaF3H was 1095 bp and it encoded a 364-amino acid protein with a predicted molecular mass of 41.18 kDa and a pI of 5.67. The recombinant protein of AaF3H was expressed in E. coli BL21(DE3) as His-tagged protein, purified by Ni-NTA agrose affinity chromatography, and functionally characterized in vitro. The results showed that the His-tagged protein (AaF3H) catalyzed naringenin to dihydrokaempferol in the present of Fe2+. The Km for naringenin was 218.03 μM. The optimum pH for AaF3H reaction was determined to be pH 8.5, and the optimum temperature was determined to be 35 °C. The AaF3H transcripts were found to be accumulated in the cultivar with higher level of flavonoids than that with lower level of flavonoids, which implied that AaF3H was a potential target for regulation of flavonoids biosynthesis in Artemisia annua through metabolic engineering. © 2016 Elsevier Masson SAS.


Tian N.,Hunan Agricultural University | Tian N.,National Research Ctr Of Engineering Technology Utilization Of Functional Ingredients From Botanicals | Tang Y.,National Research Ctr Of Engineering Technology Utilization Of Functional Ingredients From Botanicals | Xiong S.,Key Laboratory of Tea Science | And 9 more authors.
Industrial Crops and Products | Year: 2015

In order to investigate the physiological functions and biosynthesis regulation of borneol or comphore in Artermisia annua L., which is the major source of the anti-malaria drug artemisinin, the full length cDNA of the gene encoding a borneol dehydrogenase (AaBDH) was cloned from A. annua for the first time by using RACE (rapid amplification of cDNA ends). The completed open read frame of AaBDH was 1415bp and it encoded a 885-amino acid protein with a predicted molecular mass of 31.04kDa and a pI of 6.16. AaBDH showed 68-70% of amino acid identity to alcohol dehydrogenases from Solanum lycopersicum, Ppulus trichocarpa, Morus notabili and Ricinus communis. While it shared 51% and 58% of identity with artemisia alcohol dehydrogenase ADH2 from A. annua and borneol dedrogenase LiBDH from Lavandula x intermedia, respectively. The recombinant protein was obtained by heterogeneous expression of AaBDH in a strain of Escherichia coli BL 21 and purified by affinity chromatography. The function of AaBDH was characterized by using of in vitro enzymatic assays, and the results showed that AaBDH had the ability to specifically convert borneol into camphor in the presence of NAD+ (nicotinamide adenine dinucleotide) or NADP+ (nicotinamide adenine dinucleotide phosphate). The cloning of AaBDH laid a significant foundation for further investigation on physiological functions and biosynthesis regulation of plant monoterpenoids. © 2015 Elsevier B.V.


Tian N.,Hunan Agricultural University | Li J.,Key Laboratory of Tea Science | Liu S.,Hunan Agricultural University | Huang J.,Key Laboratory of Tea Science | And 2 more authors.
Biomedical Chromatography | Year: 2012

It is still a major challenge to simultaneously isolate artemisinin and its precursors, especially dihydroartemisinic acid and artemisinic acid, from herbal Artemisia annua. A rapid, economical and automatical chromatographic separation process to isolate and purify artemisinin, dihydroartemisinic acid and artemisinic acid at the same time on a preparative scale was developed. The procedure included solvent extraction of ground Artemisia annua leaves by refluxing and purification of crude extract by preparative reverse-phase high-performance liquid chromatography (RP-HPLC). Fractions containing artemisinin and its precursors were collected and identified by gas chromatography and mass spectrometry. High purity of artemisinin, dihydroartemisinic acid and artemisinic acid was obtained by preparative HPLC with a C18 column and 60% acetonitrile in water as the mobile phase. The techniques described here are useful tools for the preparative-scale isolation of artemisinin and its precursors in a fast, cost-effective and environmental friendly manner. © 2011 John Wiley & Sons, Ltd.


Tian N.,Hunan Agricultural University | Liu S.,Hunan Agricultural University | Li J.,Key Laboratory of Tea Science | Xu W.,Hunan Agricultural University | And 3 more authors.
Physiologia Plantarum | Year: 2014

Adventitious root (AR) formation is a critical process for plant clonal propagation. The role of plant secondary metabolites in AR formation is still poorly understood. Chemical and physical mutagenesis in combination with somatic variation were performed on Artemisia annua in order to obtain a mutant with changes in adventitious rooting and composition of plant secondary metabolites. Metabolic and morphological analyses of the iar (increased adventitious rooting) mutant coupled with in vitro assays were used to elucidate the relationship between plant secondary metabolites and AR formation. The only detected differences between the iar mutant and wild-type were rooting capacity and borneol/camphor content. Consistent with this, treatment with borneol in vitro promoted adventitious rooting in wild-type. The enhanced rooting did not continue upon removal of borneol. The iar mutant displayed no significant differences in AR formation upon treatment with camphor. Together, our results suggest that borneol promotes adventitious rooting whereas camphor has no effect on AR formation. © 2013 Scandinavian Plant Physiology Society.


PubMed | Key Laboratory of Tea Science and Hunan Agricultural University
Type: | Journal: Biochemical and biophysical research communications | Year: 2016

This article has been withdrawn at the request of the author(s) and/or editor. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.


Chen S.,Fujian Agriculture and forestry University | Jin X.,Fujian Agriculture and forestry University | Jin X.,Key Laboratory of Tea Science | Lin H.,Fujian Agriculture and forestry University | And 5 more authors.
Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery | Year: 2016

Solar withering is the first and essential processing during Oolong tea manufacturing, which can improve and develop a pleasant scent, especially for the floral fruity scent. The traditional technology employed hot air withering in rainy days, which lacks of light radiation, the quality of Oolong tea has no fruit floral odour and the taste is niffy green and astringency. In order to make up the light waves in rainy days or instability sunlight, an artificial light source could be considered for quality improvement during withering process in Oolong tea. In this study, solar, LED (red, yellow, blue) and dark treatments were projected for the test of physiological response, physicochemical, aroma, sensory evaluation and efficiency. Firstly, the constant temperature and humidity containing LED resource withering device for Oolong tea was developed, mainly including LED panel, air circulation channel, temperature/humidity transducer and uniform plate. The temperature/humidity transducer was applied to control the fixed conditions; Air circulation channel was projected as a medium to dehumidify and ensure the circulation of air in the box. Secondly, the test of physiological response indicated that fresh tea leaves plucking from tea plants had a limited capacity to absorb light, the net photosynthetic and transpiration rate of tea leaves increased at first and then decreased, reached peak at 10~15 min; However, the dark treatment remained negative value(-2.5 μmol/(m2·s)), mainly conduct respiration action, and when photo synthetically active radiation was 300 μmol/(m2·s), the time of withering by 30 min could be well. Thirdly, the test of biochemical component indicated that treatments exposed to different light significances increased the content of water extracts, amino acid, soluble sugar and flavones, boosted the conversion of polyphenol and decreased content of caffeine. Then, the volatile components of different treatments were assayed by chromatography-mass spectrometry detection (GC-MS). Principal component analysis method was used to evaluate the results. In contrast to dark treatment, the relative content of alpha-farnesene and nerolidol increased by 11.42% and 30.65%, respectively. The score of aroma quality exposed to solar was the highest, yellow and blue light had a bit better than red light, and dark treatment ranked the last. The sensory evaluation of quality in raw tea showed a similar trend to the results of principal component analysis. Moreover, based on light withering, the productive efficiency can be improved by 2.6 times, the grade of tea quality increased 1~2 levels, and the economic benefit enhanced by approximately 63%. In conclusion, light can regulate and improve the taste and volatiles of Oolong tea, selecting LED as an artificial light to substitute for solar withering could be a promising technology, especially for the standardization during Oolong tea manufacturing. © 2016, Chinese Society of Agricultural Machinery. All right reserved.

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