Caffeine biosynthesis in young leaves of Camellia sinensis: In vitro studies on N-methyltransferase activity involved in the conversion of xanthosine to caffeine

1996 ◽  
Vol 98 (3) ◽  
pp. 629-636 ◽  
Author(s):  
Misako Kato ◽  
Tomomi Kanehara ◽  
Hisayo Shimizu ◽  
Takeo Suzuki ◽  
Fiona M. Gillies ◽  
...  
Keyword(s):  
Camellia Sinensis ◽  
In Vitro Studies ◽  
Methyltransferase Activity ◽  
Young Leaves ◽  
Caffeine Biosynthesis

Caffeine Metabolism in High and Low Caffeine Containing Cultivars of Camellia sinensis

1995 ◽  
Vol 50 (9-10) ◽  
pp. 602-607 ◽  
Author(s):  
Hiroshi Ashihara ◽  
Hisayo Shimizu ◽  
Yoshiyuki Takeda ◽  
Takeo Suzuki ◽  
Fiona M. Gillies ◽  
...  
Keyword(s):  
Camellia Sinensis ◽  
Adenine Nucleotides ◽  
Vitro Activity ◽  
Biosynthesis Pathway ◽  
Rapid Rate ◽  
In Vitro Activity ◽  
Caffeine Content ◽  
Caffeine Biosynthesis ◽  
Caffeine Metabolism

Abstract The metabolism of [8-14C ]adenine and [2-14C]caffeine was examined in leaf segments from flush shoots of tea cultivars with high and low caffeine content. The caffeine biosynthesis pathway from AMP via theobromine was operative in both high and low caffeine containing cultivars. There was a m ore rapid rate of caffeine biosynthesis from [8-14C ]adenine in the high caffeine cultivars while the rate of degradation of both adenine nucleotides and caffeine into CO2 was greatest in cultivars with a low endogenous caffeine content. Cell-free p reparations from tea shoots contained an N-methyltransferase, that is a keyenzyme in the caffeine biosynthesis pathway; more in-vitro activity was detected in preparations from high caffeine containing cultivars. The data obtained suggest that the high caffeine containing cultivars have a more rapid rate of caffeine biosynthesis and a slower rate of caffeine catabolism than cultivars with a low endogenous caffeine content

scholarly journals Translocation of nuclei and reorientation of the mitotic apparatus in the ontogeny of stomata in Trudescuntia virginiana L.

2014 ◽  
Vol 56 (4) ◽  
pp. 599-610
Author(s):  
Jadwiga A. Tarkowska ◽  
Mirosława Ważyńska ◽  
Alina A. Jabłonowska
Keyword(s):  
In Vitro Studies ◽  
Companion Cell ◽  
Mitotic Apparatus ◽  
Tradescantia Virginiana ◽  
Young Leaves ◽  
Mother Cells ◽  
Asymmetric Mitosis

In vitro studies of the ontogeny of stomata of young leaves of <em>Tradescantia virginiana</em> L. showed that: 1) translocation of nuclei, often along long, winding paths took place in companion cell mother cells before the onset of asymmetric mitosis, 2) the reorientation of the entire mitotic apparatus took place during division of quard cell mother cells. Pertinent factors which may play a role in both processes are indicated.

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

In vitro - studies with antler bone cells: Structure forming capacity, osteocalcin production and influence of sex steroids

2006 ◽  
Vol 15 (04) ◽  
pp. 245-257 ◽  
Author(s):  
H. J. Rolf ◽  
K. G. Wiese ◽  
H. Siggelkow ◽  
H. Schliephake ◽  
G. A. Bubernik
Keyword(s):  
Sex Steroids ◽  
Bone Cells ◽  
In Vitro Studies ◽  
Osteocalcin Production
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