|Budget Amount *help
¥3,300,000 (Direct Cost : ¥3,300,000)
Fiscal Year 1998 : ¥1,700,000 (Direct Cost : ¥1,700,000)
Fiscal Year 1997 : ¥1,600,000 (Direct Cost : ¥1,600,000)
In this research, somatic embryogenesis was investigated for the enhanced regeneration efficiency from the engineering viewpoints.
1) Effects of riboflavin (RF) addition in the culture system
a) Decomposition rate of 2,4-D, a synthetic auxin, by riboflavin depended greatly on light irradiation intensity. FAD and EMN also showed the catalytic activity for the 2,4-D degradation, but lumichrome, the main product of 2,4-D decomposition, cannot.
b) Riboflavin addition into carrot cells suspension culture increased the decrease rate of 2,4-D in the cells and the medium, also enhanced the regeneration efficiency.
c) Riboflavin immobilized beads (RF-beads) were synthesized with a hydrophobic alkyl chain as a linker for the auxin decomposition.
d) The carrot cell culture with RF-beads increased the efficiency of somatic embryo formation, however the excess amount of the beads inhibited the regeneration probably because the damage to the cells by activated oxygen generated through the 2,4-D degradation.
c) A novel culture system with an auxin degradation vessel is proposed for the effective somatic embryogenesis.
2) Analysis of gas-phase composition and gas-exchanging method
a) Effects of gas components in flask headspace of carrot cell cultures were investigated for somatic cmryogcnesis. Inhibition of ethylene gas and the suppressive effect of carbon dioxide gas on it were suggested.
b) In the headspace of rice callus suspension culture, a small amount of ethanol and acetaldehyde etc. was detected, which could be an inhibitory factor for embryogenesis. However, there could not be observed any substances in the headspace gas that enhance embyogenesis.