Effect of low-intensity white light mediated de-etiolation on the biosynthesis of polyphenols in tea seedlings.
Light is an important source of energy as well as environmental signal for the regulation of biosynthesis and accumulation of multiple secondary metabolites in plants. Polyphenols are the major class of secondary metabolites in tea, which possess potential antioxidant properties. In order to investigate the effect of light signal on the regulation of biosynthesis and accumulation of polyphenols in tea seedlings, a low-intensity white light was used and the change in trends of polyphenol contents, patterns of gene expression, and corresponding enzymatic activities were studied. LC-TOF/MS analysis revealed that light signal promoted the accumulation of hydroxycinnamic acid derivatives and nongalloylated catechin (EGC), while it restrained the accumulation of β-glucogallin and galloylated catechins. The quantitative reverse transcription-PCR analysis showed that the expression levels of the regulator genes and some structural genes involved in photomorphogenesis and biosynthetic pathway of nongalloylated catechins, respectively, were up-regulated. In contrast, the expression of DHD/SDH and UGT genes, which may be involved in biosynthetic pathway of βG, was down-regulated. The corresponding in vitro enzyme assays revealed decrease in the activity of ECGT (galloylates nongalloylated catechins) and an increase in activity of GCH (hydrolyzes galloylated catechins) during de-etiolation. The present study yielded inconsistent accumulation patterns of phenolic acids, flavan-3-ols, and flavonols in tea seedlings during de-etiolation. In addition, the accumulation of catechins was possibly jointly influenced by the biosynthesis, hydrolysis, glycosylation, and galloylation of polyphenols in tea plants.
School of Life Science, Anhui Agricultural University, 130 West Changjiang Rd, Hefei, Anhui 230036, China. Electronic address: luzhongwei123456@126.com.
Zhongwei
Z
Lu
School of Life Science, Anhui Agricultural University, 130 West Changjiang Rd, Hefei, Anhui 230036, China. Electronic address: liuyajun1228@163.com.
Yajun
Y
Liu
Key Laboratory of Tea Biochemistry & Biotechnology, Ministry of Education in China, Anhui Agricultural University, 130 West Changjiang Rd, Hefei, Anhui 230036, China. Electronic address: zhaolei_tea@163.com.
Lei
L
Zhao
Key Laboratory of Tea Biochemistry & Biotechnology, Ministry of Education in China, Anhui Agricultural University, 130 West Changjiang Rd, Hefei, Anhui 230036, China. Electronic address: jiangxiaolan128@163.com.
Xiaolan
X
Jiang
Key Laboratory of Tea Biochemistry & Biotechnology, Ministry of Education in China, Anhui Agricultural University, 130 West Changjiang Rd, Hefei, Anhui 230036, China. Electronic address: mingzhuo.1234@163.com.
Mingzhuo
M
Li
School of Life Science, Anhui Agricultural University, 130 West Changjiang Rd, Hefei, Anhui 230036, China. Electronic address: wang_li09213@sina.com.
Yunsheng
Y
Wang
School of Life Science, Anhui Agricultural University, 130 West Changjiang Rd, Hefei, Anhui 230036, China. Electronic address: Yujiao_1987@163.com.
Yujiao
Y
Xu
School of Life Science, Anhui Agricultural University, 130 West Changjiang Rd, Hefei, Anhui 230036, China. Electronic address: gaolp62@126.com.
Liping
L
Gao
Key Laboratory of Tea Biochemistry & Biotechnology, Ministry of Education in China, Anhui Agricultural University, 130 West Changjiang Rd, Hefei, Anhui 230036, China. Electronic address: xiatao62@126.com.
Tao
T
Xia
D064527:Etiolation / Q000528:radiation effects; D008027:Light; D059808:Polyphenols / Q000378:metabolism*; D036226:Seedlings / Q000378:metabolism* / Q000528:radiation effects*; D013662:Tea / Q000378:metabolism* / Q000528:radiation effects*
D059808:Polyphenols; D013662:Tea
Analysis of enzymatic activities; Gene expressions; Low-intensity white light; Photomorphogenesis; Polyphenols; Tea seedlings