Purine Alkaloid Biosynthesis in Young Leaves of Camellia sinensis in Light and Darkness

2000 ◽  
Vol 113 (2) ◽  
pp. 217-221 ◽  
Author(s):  
Chie Koshiishi ◽  
Emi Ito ◽  
Ayako Kato ◽  
Yuko Yoshida ◽  
Alan Crozier ◽  
...  
Keyword(s):  
Camellia Sinensis ◽  
Alkaloid Biosynthesis ◽  
Purine Alkaloid ◽  
Young Leaves

Expression for Caffeine Biosynthesis and Related Enzymes in Camellia sinensis

2010 ◽  
Vol 65 (3-4) ◽  
pp. 245-256 ◽  
Author(s):  
Misako Kato ◽  
Naoko Kitao ◽  
Mariko Ishida ◽  
Hanayo Morimoto ◽  
Fumi Irino ◽  
...  
Keyword(s):  
Gene Expression ◽  
Camellia Sinensis ◽  
Heavy Metal Stress ◽  
Tea Plant ◽  
Purine Base ◽  
Caffeine Synthase ◽  
Purine Alkaloid ◽  
Young Leaves ◽  
Caffeine Biosynthesis ◽  
High Concentrations

Caffeine (1,3,7-trimethylxanthine) is a purine alkaloid that is present in high concentrations in the tea plant Camellia sinensis. Caffeine synthase (CS, EC 2.1.1.160) catalyzes the S-adenosyl-L-methionine-dependent N-3- and N-1-methylation of the purine base to form caffeine, the last step in the purine alkaloid biosynthetic pathway. We studied the expression profile of the tea caffeine synthase (TCS) gene in developing leaves and flowers by means of northern blot analysis, and compared it with those of phenylalanine ammonia lyase (PAL, EC 4.3.1.5), chalcone synthase (CHS, EC 2.3.1.74), and S-adenosyl-L-methionine synthase (SAMS, EC 2.5.1.6). The amount of TCS transcripts was highest in young leaves and declined markedly during leaf development, whereas it remained constant throughout the development of the flower. Environmental stresses other than heavy metal stress and plant hormone treatments had no effect on the expression of TCS genes, unlike the other three genes. Drought stress suppressed TCS gene expression in leaves, and the expression pattern mirrored that of the dehydrin gene. The amounts of TCS transcripts increased slightly on supply of a nitrogen source. We discuss the regulation of TCS gene expression

scholarly journals Tolerance to water stress in boron-deficient tea (Camellia sinensis) plants

2012 ◽  
Vol 24 (1) ◽  
pp. 41-51 ◽  
Author(s):  
Roghieh Hajiboland ◽  
Soodabe Bastani
Keyword(s):  
Water Stress ◽  
Camellia Sinensis ◽  
Stress Conditions ◽  
Assimilation Rate ◽  
Antioxidant Defence System ◽  
Young Leaves ◽  
Net Assimilation ◽  
Single Stress ◽  
Tea Plants ◽  
Lower Ratio

Tolerance to water stress in boron-deficient tea (Camellia sinensis) plantsThe effects of boron (B) deficiency and water stress were studied in tea plants (Camellia sinensis[L.] O. Kuntze) grown in growth chambers in perlite irrigated with a nutrient solution. Dry matter production was reduced significantly by both low B supply and water stress. Shoot-root translocation of B declined in water-stressed plants. In addition, the re-translocation of B was impaired under drought, which was reflected in a significantly lower ratio of B content of young to old leaves in both B-deficient and B-sufficient plants. Leaf photochemical parameters were negatively influenced by B deficiency and water stress in the old but not in the young leaves. Although B-deficient plants were more conservative in relation to water loss following elevated stomatal limitation, their water potential was lower than in B-sufficient plants irrespective of the watering regime. Under the combined effects of B deficiency and water stress, the reduction in the CO2assimilation rate was more prominent than that under a single stress factor. The reduction of the net assimilation rate (A) in B-deficient plants due to water stress and in water-stressed plants due to low B supply were not accompanied by significant changes in the stomatal conductance, suggesting an involvement of non-stomatal factors. The activity of antioxidant enzymes and proline content increased under B deficiency and water stress conditions. Our results suggested that, in young leaves that have been developed under water stress, an acclimation to water stress conditions occurred that was well reflected in their more stable photochemistry, water relations and an efficient antioxidant defence system compared with the older leaves.

scholarly journals Identifying Genes Involved in Alkaloid Biosynthesis in Vinca minor through Transcriptomics and Gene Co-Expression Analysis

Biomolecules ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1595
Author(s):  
Emily Amor Stander ◽  
Liuda Johana Sepúlveda ◽  
Thomas Dugé de Bernonville ◽  
Inês Carqueijeiro ◽  
Konstantinos Koudounas ◽  
...  
Keyword(s):  
Candidate Genes ◽  
Biosynthetic Pathway ◽  
Fluorescent Proteins ◽  
Light Exposure ◽  
Indole Alkaloids ◽  
High Light ◽  
Alkaloid Biosynthesis ◽  
Vinca Minor ◽  
Young Leaves ◽  
Derivatives Of

The lesser periwinkle Vinca minor accumulates numerous monoterpene indole alkaloids (MIAs) including the vasodilator vincamine. While the biosynthetic pathway of MIAs has been largely elucidated in other Apocynaceae such as Catharanthus roseus, the counterpart in V. minor remains mostly unknown, especially for reactions leading to MIAs specific to this plant. As a consequence, we generated a comprehensive V. minor transcriptome elaborated from eight distinct samples including roots, old and young leaves exposed to low or high light exposure conditions. This optimized resource exhibits an improved completeness compared to already published ones. Through homology-based searches using C. roseus genes as bait, we predicted candidate genes for all common steps of the MIA pathway as illustrated by the cloning of a tabersonine/vincadifformine 16-O-methyltransferase (Vm16OMT) isoform. The functional validation of this enzyme revealed its capacity of methylating 16-hydroxylated derivatives of tabersonine, vincadifformine and lochnericine with a Km 0.94 ± 0.06 µM for 16-hydroxytabersonine. Furthermore, by combining expression of fusions with yellow fluorescent proteins and interaction assays, we established that Vm16OMT is located in the cytosol and forms homodimers. Finally, a gene co-expression network was performed to identify candidate genes of the missing V. minor biosynthetic steps to guide MIA pathway elucidation.

Calonectria theae. [Descriptions of Fungi and Bacteria].

1974 ◽  
Author(s):  
A. Peerally
Keyword(s):  
Geographical Distribution ◽  
Camellia Sinensis ◽  
Shade Tree ◽  
Mature Leaves ◽  
Young Leaves

Abstract A description is provided for Calonectria theae. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Acacia spp., Albizia, Camellia sinensis, Eucalyptus spp. and Rhododendron (Azalea). DISEASE: Causes the well-known 'Cercosporella disease' of tea bushes. Spots on young leaves are at first brown or black and in humid weather enlarge and coalesce. On mature leaves spots are at first black then grey or greyish-white with a purplish margin. On fully mature leaves spots are brown or black then turn greyish. Tea bushes may be severely defoliated. Also causes root discoloration but not mortality of azaleas (52, 1935). GEOGRAPHICAL DISTRIBUTION: Ceylon and USA. Other records are of doubtful authenticity TRANSMISSION: By wind-borne conidia and ascospores in Ceylon. Transmission from Acacia decurrens, used as a shade tree, frequently reported.

scholarly journals Occurrence, Biosynthesis and Metabolism of Theanine (γ-Glutamyl-L-ethylamide) in Plants: A Comprehensive Review

2015 ◽  
Vol 10 (5) ◽  
pp. 1934578X1501000 ◽  
Author(s):  
Hiroshi Ashihara
Keyword(s):  
Amino Acid ◽  
Light Intensity ◽  
Glutamic Acid ◽  
Camellia Sinensis ◽  
Xylem Sap ◽  
Tea Leaves ◽  
Major Site ◽  
Protein Amino Acid ◽  
Comprehensive Review ◽  
Young Leaves

Theanine (γ-glutamyl-L-ethylamide) is the most abundant non-protein amino acid in tea leaves. In addition to Camellia sinensis, theanine occurs in several plants belonging to the Ericales. Biosynthesis of theanine from glutamic acid and ethylamine by theanine synthetase is present in all organs of tea seedlings, but roots are the major site of theanine biosynthesis in adult tea trees. Theanine is transported from roots to young leaves via the xylem sap. Theanine is hydrolysed to glutamic acid and ethylamine in leaves. Ethylamine produced from theanine is predominantly used for catechin biosynthesis. Concentration of ammonia and light intensity influence the biosynthesis and degradation of theanine, respectively. Biosynthesis, translocation and degradation of theanine and related enzymes and genes are reviewed.

scholarly journals First Report of Alternaria alternata Causing Leaf Spots of Tea (Camellia sinensis) in China

Plant Disease ◽  
2014 ◽  
Vol 98 (5) ◽  
pp. 697-697 ◽  
Author(s):  
L. X. Zhou ◽  
W. X. Xu
Keyword(s):  
Camellia Sinensis ◽  
Alternaria Alternata ◽  
Plant Diseases ◽  
Unknown Etiology ◽  
Leaf Spot Disease ◽  
Post Inoculation ◽  
Tea Leaves ◽  
First Report ◽  
Leaf Spots ◽  
Young Leaves

Tea is the most popular non-alcoholic beverage crop in the world, which originated in China and has been cultivated in over 45 countries. In recent years, a leaf spot disease of unknown etiology has been observed on young leaves of tea trees (Camellia sinensis) grown in Luotian county, Hubei Province, China. Observed symptoms display grayish brown to white spots (about 1 cm in diameter) surrounded by brown edges. Over 20% of the young leaves were affected on surveyed trees. To identify the pathogen, six symptomatic tea leaves were collected from six individual tea trees of unknown variety in August 2012. A thin section (3 to 5 mm) of symptomatic tissue was sterilized in a bleach solution of 3% hypochlorite and placed on potato dextrose agar (PDA) medium at 25°C in darkness for isolation. Six fungal colonies displaying gray-brown and gray-white aerial mycelia were consistently recovered from lesions of the six leaves, termed as T1 to T6, respectively. Conidia produced on the colonies were olive brown, obpyriform, short conical beak at the tip, 0 to 3 vertical and 1 to 6 transverse septa, and length × width of 7.1 to 31.7 (avg. 20.1) × 2.9 to 12.7 (avg. 7.2) μm. T1 to T6 were identified as Alternaria alternata on the basis of morphological characterization, respectively (2). Confirmation of the species identification was obtained by molecular characterization of their internal transcribed spacer (ITS) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) regions amplified from the genomic DNAs using the universal primers (1). The results revealed identical sequences of ITS (GenBank Accession No. KF699530) and GAPDH among the six isolates. BLAST searches showed that they had the highest similarity with A. alternata strains, with 98.3% for ITS (AJ276055) and 96.2% for GAPDH (EF513205), deposited in fungus database ( http://www.mycobank.org/ ). Pathogenicity tests were conducted on the detached leaves expanding for 10 to 20 days of two tea varieties (cvs. Fudingdabai and Taicha No. 12) in triplicate by placing 4 mm diameter discs from 5-day-old PDA plates of T3 and T6, which were incubated in an incubator at 25°C with a 12-h photoperiod for 7 days. All inoculated leaves with or without wound treatment developed brown spots similar to the original ones at 7 days post inoculation (dpi) while the control leaves inoculated with non-colonized PDA plugs remained asymptomatic. Isolates recovered from diseased samples were of the same morphology and ITS sequence as the inoculated ones. Alternaria alternata had been described on C. sinensis in China (3), but it was only reported as a severe foliar fungal pathogen of tea in North Bengal, India (1), and to our knowledge, this is the first report of A. alternata causing leaf spots on tea leaves (C. sinensis) in China. In addition to quantity loss, the species may result in a decrease of quality of tea crop considering that it can produce Alternaria toxins related to animal and public health. The etiologic identification of the disease is expected to provide useful information for its control. References: (1) B. N. Chakraborty et al. Plant Pathol. 55:303, 2006. (2) E. G. Simmons. Page 1 in: Alternaria Biology, Plant Diseases and Metabolites. J. Chelchowski and A. Visconti, eds. Elsevier, Amsterdam, 1992. (3) F. L. Tai. Page 1527 in: Sylloge Fungorum Sinicorum. eds. Sci. Press Acad. Sin. Beijing, 1979. (4) B. S. Weir et al. Stud. Mycol. 73:115, 2012.

scholarly journals Occurrence and De novo Biosynthesis of Caffeine and Theanine in Seedlings of Tea (Camellia sinensis)

2015 ◽  
Vol 10 (5) ◽  
pp. 1934578X1501000 ◽  
Author(s):  
Wei-Wei Deng ◽  
Hiroshi Ashihara
Keyword(s):  
Secondary Metabolites ◽  
Camellia Sinensis ◽  
De Novo ◽  
Relative Concentration ◽  
Tea Leaves ◽  
Fresh Weight ◽  
Biosynthetic Activity ◽  
De Novo Biosynthesis ◽  
Young Leaves ◽  
Different Parts

Caffeine (1,3,7-trimethyl xanthine) and theanine (γ-glutamyl-L-ethylamide) are the major nitrogen-containing secondary metabolites in tea leaves. The aim of the present study was to elucidate the relative concentration and amounts of these compounds and the de novo biosynthetic activity in different parts of tea seedlings grown for 27-, 106- and 205 days. The results indicated that caffeine and its biosynthetic activity occur only in leaves and stems, while theanine is distributed in all organs, including roots. The concentration of caffeine and theanine in leaves ranged from 0.3–1.1 mg N/g and 0.1–0.5 mg N/g fresh weight, respectively. A higher concentration of theanine was found in roots (0.5–1.1 mg N). The total amounts of theanine expressed as g N/seedling were 1.1–1.5 times higher than that of caffeine. The high biosynthetic activity of caffeine from NH4+ was found in young leaves during the first 106 days after germination. Theanine biosynthetic activity probably occurs in roots, since higher 15N atom% excess was observed in roots during the first 27 days. Theanine may be synthesized mainly in roots and translocated to leaves. The de novo biosynthesis of caffeine and theanine in tea seedlings and their accumulation and translocation are discussed.

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