@Article{taiwania1999442202,
AUTHOR = {Shu-Jen Wang, Kai-Wun Yeh, Heng-Long Wang, Jong-Ching Su and Chia-Yin Tsai},
TITLE = {Light-Induced Circadian Expression of Starch Granule-Bound Starch Synthase Gene in Cell Suspension Cultures of 
Sweet Potato},
JOURNAL = {Taiwania},
VOLUME = {44},
YEAR = {1999},
ISSUE = {2},
PAGES = {202-211},
URL = {https://taiwania.ntu.edu.tw/abstract/133},
ABSTRACT = {Attempts were made to evaluate whether suspension cell cultures of sweet potato could be used as a tool for studying gene expression controlled by circadian clocks. Starch granule-bound starch synthase (GBSS) gene, which exhibited a circadian rhythm in the leaf tissue but expressed constantly in dark-adapted cell cultures, was used as a marker gene for the study. Because light is considered as a major signal to set  circadian  clocks,  dark-adapted  cells  were  entrained  by 
16 h light/8 h dark photoperiod for 7 days before determination for the expression of GBSS gene. Results of RNA blot analysis showed that fluctuations of GBSS mRNA during a diurnal cycle could be induced in cell cultures and the pattern of rhythm was similar to that of the leaf tissue. In addition to light effect, other environmental factors such as osmotic stress were also evaluated. Expression of GBSS gene was enhanced by 600 mM sorbitol in the dark-adapted cells; however, the pattern of circadian rhythm established under 16 L/8 D photoperiod was repressed by the high osmotic effect. These results not only indicate that the circadian clock could be set by light but also provide evidence that suspension cells might be used for studying the regulation of circadian rhythm.},
DOI = {10.6165/tai.1999.44(2).202}
}