The effect of hormones on anthocyanin accumulation in cell cultures of Haplopappus gracilis.

Suspension cultures of Haplopappus gracilis accumulated anthocyanin when grown in defined media with 4.5×10(-6)M 2,4-D. Transfer of cells to media with 10(-5)M kinetin or benzyladenine and no auxin or 10(-7)M NAA for 6 days resulted in increased anthocyanin concentration of the cells but the total amount of pigment was unaffected due to differences in growth rates. The cultures yielded up to 35 mg pigment per gram dry weight.Cells grown in batch culture in media with 10(-5)M kinetin and with 10(-7) M NAA or 5×10(-5)M NAA sampled and analyzed daily grew at the same rate. The concentration of anthocyanin differed, being lower in cells at 5×10(-5)M NAA. After 6 days there was a rapid increase in pigment formation, and by 14 days the concentration of anthocyanin in cells in the two media were the same.When the cells were cultured in 3.5-1 phytostats and 600 ml culture was replaced daily with 600 ml medium, anthocyanins accumulated when the NAA concentration was 10(-7)M but not at 10(-6)M. At 10(-7)M NAA the cultures remained pigmented and anthocyanin accumulation could be restored after a temporary loss of pigmentation due to an earlier, higher auxin concentration. The changes in concentration of phenylalanine ammonia-lyase did not correspond to changes in the rate of anthocyanin accumulation. The enzyme showed a maximum 4-8 h after inoculation of cells to fresh media. Cells grown on agar plates and rich in anthocyanin were observed to divide without loss of pigmentation, demonstrating that cells differentiated with respect to anthocyanin production undergo mitosis.