Carotenoids accumulation and expression of carotenogenesis genes during seedling and leaf development in Chinese cabbage ('Brassica rapa subsp. pekinensis')
Tuan, Pham Anh; Park, Nam Il; Park, Woo Tae; ...
To investigate the regulation mechanisms of carotenoid biosynthesis
in Chinese cabbage (Brassica rapa subsp. pekinensis), carotenoids
accumulation and carotenogenesis genes (BrPSY, BrPDS, BrZDS, BrLCYB,
BrLCYE, BrCHXB, BrZEP, and BrNCED) involved in carotenoids biosynthesis
were analyzed during seedling and leaf development using real-time PCR.
For seedling, some of carotenogenesis genes were showed similar to
expression pattern between under dark and light condition.
Carotenogenesis genes reached the maximum transcription at 8 days after
sowing and this was similar to the highest contents of most detected
carotenoids. Carotenoids contents (mainly lutein and [beta]-carotene) in
light-grown seedlings were several time higher than those in dark-grown
ones. For leaf development, direct lighted-outer leaves contain a
30-fold higher carotenoid amount compared to inner and middle leaves.
However, expression level of carotenogenesis genes in outer leaves did
not show a big different with those in inner and middle leaves. These
results suggest a considerable role of light in carotenoids biosynthesis
during seedling and leaf development.
Keywords: Carotenoid, Brassica rapa, Chinese cabbage,
carotenogenesis genes, gene expression.
Abbreviations: DEPC, diethylpyrocarbonate; DW, dry weight; HPLC,
high-performance liquid chromatography; DAS, days after sowing; GGDP,
geranylgeranyl diphosphate; PSY, phytoene synthase; PDS, phytoene
desaturase; ZDS, [xi]-carotene desaturase; LCYB, lycopene
[beta]-cyclase; LCYE, lycopene [epsilon]-cyclase; CHXB, [beta]-ring
carotene hydroxylase; CHXE, [epsilon]-ring carotene hydroxylase; ZEP,
zeaxanthin epoxidase; NCED, 9-cis epoxycarotenoid dioxygenase; I-leaves,
inner leaves; M-leaves, middle leaves; O-leaves, outer leaves.