| Budget Amount *help |
¥2,500,000 (Direct Cost: ¥2,500,000)
Fiscal Year 1987: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1986: ¥2,000,000 (Direct Cost: ¥2,000,000)
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| Research Abstract |
Carrot suspension cells in a medium containing 2,4-D are fractionated and transferred and cultured in a medium containing 10^<-7>M zeatin but lacking 2,4-D, cells of lower density (<12% Ficoll) synthesize anthocyanin while those of higher density (>14% Ficoll) form somatic embryos. 1. When the membrane potenitals of cultured carrot cells were measured in culture medium, it was about -40 mV and did not change by addition of salts or addition (or depletion) of 2,4-D. 2. When the measurement was performed in test medium (containing low concentration of salts), the values were widely distributed (from -60 to -110 mV)and changed largely with external concentration of K^+ but no Mg^<++> or Ca^<++>. 3. When the cells were fractionated by Ficoll density gradient centrifugation, the membrane potential of the cells of higher density (>14% Ficoll) was about -150 mV in the test medium and did not change during embryogenesis with depletion of 2,4-D. On the otherhand, the membrane potential of the cells of lower density (banding between 6 - 10% Ficoll) was less negative (-60<wave> -110 mV) in the test medium. When such cells were transferred and cultured in the medium containing zeatin but lacking 2,4-D, the membrane potential was shifted negatively by about 15 mV prior to anthocyanin synthesis. When the 2,4-D was added to anthocyanin-synthesizing cells in the medium containing zeatin, a transient hyperpolarization and subsequent depolarization of the membrane were observed prior to the inhibition of anthocyanin synthesis.
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