The role of light in the regulation of anthocyanin accumulation in Gerbera hybrida

被引:102
作者
Meng, XC
Xing, T
Wang, XJ [1 ]
机构
[1] S China Normal Univ, Coll Life Sci, Guangdong Key Lab Biotechnol Plant Dev, Guangzhou 510631, Peoples R China
[2] Carleton Univ, Dept Biol, Ottawa, ON K1S 5B6, Canada
基金
中国国家自然科学基金;
关键词
anthocyanin; CHS and DFR gene expression; light; photoreceptor; ray floret (rf);
D O I
10.1007/s10725-004-4454-6
中图分类号
Q94 [植物学];
学科分类号
071001 ;
摘要
In the present work, the pigmentation regulated by light was investigated in ray floret (rf) of Gerbera hybrida. When inflorescences from stage 1 were covered with aluminium foil in vivo the pigmentation of the rf petals was strongly blocked and the gene expression of CHS ( Chalcone synthase) and DFR ( Dihydroflavonol-4-reductase) was inhibited. Similar results were obtained when the detached rfs were cultured in vitro. Covering of the leaves on the plants resulted in reduced pigmentation compared with the covering of inflorescences in vivo. Removal of the green bracts did not affect the pigmentation significantly and the anthocyanin concentration was maintained at a level similar to that of the control. The ultrastructure of the plastids in rf petals was examined to investigate the possible role of photosynthesis in light regulation of flower pigmentation. Plastids within rf epidermal cells showed a characteristic chloroplast morphology in flowers at stage 2, which deteriorated by stage 3. They then changed to a chromoplast- like structure in fully opened rf petals ( stage 6). Similar chromoplast- like structures were observed in the plastids of the rf petals from inflorescences both shaded in vivo and in vitro. Additionally, DCMU, a photosynthetic inhibitor, did not show a significant effect on light-induced anthocyanin accumulation. Our data suggest that light is an important factor for pigmentation of rf petal in Gerbera and the petal itself acts as a light sensor site to perceive the light signal. From the different light qualities evaluated, blue light promoted gene expression of CHS and DFR, and red light enhanced the gene expression of CHS, indicating the photoreceptors responding to blue and red light involved in the photoregulation of flower pigmentation in Gerbera.
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页码:243 / 250
页数:8
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