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Relationship between gene expression and the accumulation of catechin during spring and autumn in tea plants (Camellia sinensis L.).

Liu M, Tian HL, Wu JH, Cang RR, Wang RX, Qi XH, Xu Q, Chen XH - Hortic Res (2015)

Bottom Line: Tea is popular worldwide given the plant's health benefits.The results indicated that the total catechin (TC) concentrations were significantly higher in tea plants harvested in autumn than in those harvested in spring, based on higher concentrations of epigallocatechin (EGC) in autumn tea (P<0.01).The expression of the genes phenylalanine ammonia-lyase (PAL), flavanone 3-hydroxylase (F3H), flavonoid 3',5'-hydroxylase (F3'5'H), dihydroflavonol 4-reductase (DFR), and anthocyanidin synthase (ANS) is closely related to the TC content of tea plants in both spring and autumn.

View Article: PubMed Central - PubMed

Affiliation: School of Horticulture and Plant Protection, Yangzhou University , 48 Wenhui East Road, Yangzhou, Jiangsu 225009, P. R. China.

ABSTRACT
The tea plant (Camellia sinensis L.) is an important commercial crop with remarkably high catechin concentrations. Tea is popular worldwide given the plant's health benefits. Catechins are the main astringent substance in tea and are synthesized mainly via the phenylpropanoid pathway. In this study, eight cultivars of tea plants harvested both in spring and autumn were used to investigate differences in catechin concentrations by using high-performance liquid chromatography. The expression levels of genes associated with catechin biosynthesis were investigated using reverse transcription-quantitative polymerase chain reaction. The results indicated that the total catechin (TC) concentrations were significantly higher in tea plants harvested in autumn than in those harvested in spring, based on higher concentrations of epigallocatechin (EGC) in autumn tea (P<0.01). The expression of the genes phenylalanine ammonia-lyase (PAL), flavanone 3-hydroxylase (F3H), flavonoid 3',5'-hydroxylase (F3'5'H), dihydroflavonol 4-reductase (DFR), and anthocyanidin synthase (ANS) is closely related to the TC content of tea plants in both spring and autumn. Positive correlations between PAL, cinnamate 4-hydroxylase (C4H), F3H, and DFR expression and EGC accumulation in autumn tea were identified, with correlation coefficients of 0.710, 0.763, 0.884, and 0.707, respectively. A negative correlation between ANS expression level and EGC concentrations in tea plants harvested in spring was noted (r=-0.732). Additionally, negative correlations between F3H and ANS expression levels and the catechin content were identified in spring tea, whereas the correlations were positive in autumn tea. Significant differences in the F3H and ANS expression levels between spring and autumn tea indicate that F3H and ANS are potentially key genes affecting catechin accumulation in tea plants.

No MeSH data available.


Related in: MedlinePlus

Possible biosynthetic pathways of catechins in tea (Camellia sinensis) leaves.9,10,22 Key enzyme names are: PAL, phenylalanine ammonia-lyase; C4H, cinnamate 4-hydroxylase; CHS, chalcone synthase; CHI, chalcone isomerase; F3H, flavanone 3-hydroxylase; F3′H, flavonoid 3′-hydroxylase; F3′5′H, flavonoid 3′,5′-hydroxylase; DFR, dihydroflavonol 4-Reductase; LAR, leucocyanidin reductase; ANR, anthocyanidin reductase; ANS, anthocyanidin synthase; FGS, flavan-3-ol gallate synthase.
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fig1: Possible biosynthetic pathways of catechins in tea (Camellia sinensis) leaves.9,10,22 Key enzyme names are: PAL, phenylalanine ammonia-lyase; C4H, cinnamate 4-hydroxylase; CHS, chalcone synthase; CHI, chalcone isomerase; F3H, flavanone 3-hydroxylase; F3′H, flavonoid 3′-hydroxylase; F3′5′H, flavonoid 3′,5′-hydroxylase; DFR, dihydroflavonol 4-Reductase; LAR, leucocyanidin reductase; ANR, anthocyanidin reductase; ANS, anthocyanidin synthase; FGS, flavan-3-ol gallate synthase.

Mentions: Catechins account for approximately 70% of all polyphenols in tea and are derived from multiple branches of the phenylpropanoid biosynthetic pathway, one of the most characterized secondary metabolic routes in plant systems.8–10 Flavan-3-ols (also known as catechins) are mainly produced via the naringenin-chalcone → naringenin → dihydrokaempferol pathway (Ashihara et al., 2010).11 As shown in Figure 1, the steps to produce dihydromyricetin are catalyzed by the following enzymes: phenylalanine ammonia-lyase (PAL), cinnamate 4-hydroxylase (C4H), chalcone synthase (CHS), chalcone isomerase (CHI), flavanone 3-hydroxylase (F3H), flavonoid 3′-hydroxylase (F3′H), and flavonoid 3′,5′-hydroxylase (F3′5′H).12–18 Dihydroflavonol 4-reductase (DFR) catalyzes important steps in the control of metabolic fluxes, which feed into biosynthetic pathway branches, leading to the production of anthocyanins and proanthocyanidins.19 Non-esterified catechins are produced in steps involving sequential reactions catalyzed by leucoanthocyanidin 4-reductase (LAR), anthocyanidin synthase (ANS), and anthocyanidin reductase (ANR).20–22 EGC and EC are converted into esterified catechins (EGCG and ECG) via the sequential action of flavan-3-ol gallate synthase (FGS),11 and various catechin monomers are synthesized from dihydrogen arbutus pigment.10,11,23


Relationship between gene expression and the accumulation of catechin during spring and autumn in tea plants (Camellia sinensis L.).

Liu M, Tian HL, Wu JH, Cang RR, Wang RX, Qi XH, Xu Q, Chen XH - Hortic Res (2015)

Possible biosynthetic pathways of catechins in tea (Camellia sinensis) leaves.9,10,22 Key enzyme names are: PAL, phenylalanine ammonia-lyase; C4H, cinnamate 4-hydroxylase; CHS, chalcone synthase; CHI, chalcone isomerase; F3H, flavanone 3-hydroxylase; F3′H, flavonoid 3′-hydroxylase; F3′5′H, flavonoid 3′,5′-hydroxylase; DFR, dihydroflavonol 4-Reductase; LAR, leucocyanidin reductase; ANR, anthocyanidin reductase; ANS, anthocyanidin synthase; FGS, flavan-3-ol gallate synthase.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4595990&req=5

fig1: Possible biosynthetic pathways of catechins in tea (Camellia sinensis) leaves.9,10,22 Key enzyme names are: PAL, phenylalanine ammonia-lyase; C4H, cinnamate 4-hydroxylase; CHS, chalcone synthase; CHI, chalcone isomerase; F3H, flavanone 3-hydroxylase; F3′H, flavonoid 3′-hydroxylase; F3′5′H, flavonoid 3′,5′-hydroxylase; DFR, dihydroflavonol 4-Reductase; LAR, leucocyanidin reductase; ANR, anthocyanidin reductase; ANS, anthocyanidin synthase; FGS, flavan-3-ol gallate synthase.
Mentions: Catechins account for approximately 70% of all polyphenols in tea and are derived from multiple branches of the phenylpropanoid biosynthetic pathway, one of the most characterized secondary metabolic routes in plant systems.8–10 Flavan-3-ols (also known as catechins) are mainly produced via the naringenin-chalcone → naringenin → dihydrokaempferol pathway (Ashihara et al., 2010).11 As shown in Figure 1, the steps to produce dihydromyricetin are catalyzed by the following enzymes: phenylalanine ammonia-lyase (PAL), cinnamate 4-hydroxylase (C4H), chalcone synthase (CHS), chalcone isomerase (CHI), flavanone 3-hydroxylase (F3H), flavonoid 3′-hydroxylase (F3′H), and flavonoid 3′,5′-hydroxylase (F3′5′H).12–18 Dihydroflavonol 4-reductase (DFR) catalyzes important steps in the control of metabolic fluxes, which feed into biosynthetic pathway branches, leading to the production of anthocyanins and proanthocyanidins.19 Non-esterified catechins are produced in steps involving sequential reactions catalyzed by leucoanthocyanidin 4-reductase (LAR), anthocyanidin synthase (ANS), and anthocyanidin reductase (ANR).20–22 EGC and EC are converted into esterified catechins (EGCG and ECG) via the sequential action of flavan-3-ol gallate synthase (FGS),11 and various catechin monomers are synthesized from dihydrogen arbutus pigment.10,11,23

Bottom Line: Tea is popular worldwide given the plant's health benefits.The results indicated that the total catechin (TC) concentrations were significantly higher in tea plants harvested in autumn than in those harvested in spring, based on higher concentrations of epigallocatechin (EGC) in autumn tea (P<0.01).The expression of the genes phenylalanine ammonia-lyase (PAL), flavanone 3-hydroxylase (F3H), flavonoid 3',5'-hydroxylase (F3'5'H), dihydroflavonol 4-reductase (DFR), and anthocyanidin synthase (ANS) is closely related to the TC content of tea plants in both spring and autumn.

View Article: PubMed Central - PubMed

Affiliation: School of Horticulture and Plant Protection, Yangzhou University , 48 Wenhui East Road, Yangzhou, Jiangsu 225009, P. R. China.

ABSTRACT
The tea plant (Camellia sinensis L.) is an important commercial crop with remarkably high catechin concentrations. Tea is popular worldwide given the plant's health benefits. Catechins are the main astringent substance in tea and are synthesized mainly via the phenylpropanoid pathway. In this study, eight cultivars of tea plants harvested both in spring and autumn were used to investigate differences in catechin concentrations by using high-performance liquid chromatography. The expression levels of genes associated with catechin biosynthesis were investigated using reverse transcription-quantitative polymerase chain reaction. The results indicated that the total catechin (TC) concentrations were significantly higher in tea plants harvested in autumn than in those harvested in spring, based on higher concentrations of epigallocatechin (EGC) in autumn tea (P<0.01). The expression of the genes phenylalanine ammonia-lyase (PAL), flavanone 3-hydroxylase (F3H), flavonoid 3',5'-hydroxylase (F3'5'H), dihydroflavonol 4-reductase (DFR), and anthocyanidin synthase (ANS) is closely related to the TC content of tea plants in both spring and autumn. Positive correlations between PAL, cinnamate 4-hydroxylase (C4H), F3H, and DFR expression and EGC accumulation in autumn tea were identified, with correlation coefficients of 0.710, 0.763, 0.884, and 0.707, respectively. A negative correlation between ANS expression level and EGC concentrations in tea plants harvested in spring was noted (r=-0.732). Additionally, negative correlations between F3H and ANS expression levels and the catechin content were identified in spring tea, whereas the correlations were positive in autumn tea. Significant differences in the F3H and ANS expression levels between spring and autumn tea indicate that F3H and ANS are potentially key genes affecting catechin accumulation in tea plants.

No MeSH data available.


Related in: MedlinePlus