• BMB Reports
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• v.41 no.2
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• pp.112-118
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• 2008

Camptothecin is an anti-cancer monoterpene indole alkaloid. The gene encoding 1-hydroxy-2-methyl-2-(E)-butenyl 4-diphosphate reductase (designated as CaHDR), the last catalytic enzyme of the MEP pathway for terpenoid biosynthesis, was isolated from camptothecin-producing Camptotheca acuminata. The full-length cDNA of CaHDR was 1686 bp encoding 459 amino acids. Comparison of the cDNA and genomic DNA of CaHDR revealed that there was no intron in genomic CaHDR. Southern blot analysis indicated that CaHDR belonged to a low-copy gene family. RT-PCR analysis revealed that CaHDR expressed constitutively in all tested plant organs with the highest expression level in flowers, and the expression of CaHDR could be induced by 100 ${\mu}M$ methyl-jasmonate (MeJA), but not by 100 mg/L salicylic acid (SA) in the callus of C. acuminata. The complementation of CaHDR in Escherichia coli ispH mutant MG1655 demonstrated its function.

• Plant Biotechnology Reports
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• v.2 no.2
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• pp.163-169
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• 2008

Roots of Ophiorrhiza prostrata D. Don serve as a rich source of camptothecin (CPT), an anticancer drug. Because of the large-scale collection of its roots, the plant has become a threatened species. The present study accomplishes the induction of adventitious roots as a means for the production of CPT as well as for the large-scale propagation of this anticancer drug plant using leaf and internode explants. The biomass yield and CPT content of adventitious roots induced from different explants were compared to roots developed on ex vitro rooted stem cuttings. Adventitious roots were produced on half-strength Murashige and Skoog (MS) medium supplemented with $10.74{\mu}M$ ${\alpha}-naphthaleneacetic$ acid and $2.32{\mu}M$ kinetin at mean fresh weights of 0.753, 0.739 and 0.748 g roots from leaf, internode and shoot, respectively. CPT yield from in vitro derived roots after 50, 80 and 120 days of incubation (0.028, 0.06 and 0.1% dry weight, respectively) was not significantly different from those harvested at the same age from ex vitro rooted (0.03, 0.06 and 0.13%, respectively) stem cuttings. CPT from subcultured roots derived from solid (0.08%) medium was lower than from suspension culture medium (0.12%). Subsequent cultures of the adventitious roots showed a stable production of CPT (0.16%). The yield of CPT from 360-day-old plant-derived roots was 0.19%. Elicitation using methyl jasmonate and acetyl salicylic acid exhibited no enhancement in CPT yield. In vitro propagation through direct shoot regeneration was achieved from the adventitious roots upon transfer to MS medium with $8.87{\mu}M$ $N^6-benzyladenine$ (BA) and $2.46{\mu}M$ indole-3-butyric acid (IBA) with a mean of 21.2 shoots per culture in 50 days. The shoots upon subculture on medium having the same level of BA and IBA underwent rapid proliferation. The shoots transferred to field conditions after in vitro rooting exhibited 95% survival. Adventitious root induction, from leaf and internode explants, enables the feasible production of CPT as well as the large-scale rapid propagation of this species which can safeguard it from extinction.

• Korean Journal of Weed Science
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• v.18 no.2
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• pp.136-145
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• 1998

This study was conducted to determine the growth characteristics, and the effect of plant growth regulators on the sprouting and growth of purple nutsedge(Cyperus rotundus L.) in order to establish effective control system in lawn ground. The flowering of purple nutsedge was initiated 30 days after transplanting regardless of the transplanting time. Low temperature less than $10^{\circ}C$ after flowering was required for tuber formation, showing that the tuberization was related to air temperature. Shoot number and dry weight of underground portion of purple nutsedge was slightly affected by plant growth regulators such as benzylamino purine, abscisic acid, brassinosteroid and jasmonate. Imazaquin applied at 1, 2 and 3 weeks after transplanting induced multi-shooting and inhibited shoot growth indicating that the herbicide played a role as plant growth regulator at a concentration of 30 and 60g ai/10a. The greatest inhibition of purple nutsedge was obtained by pyrazosulfuron-ethyl as applied 1 weeks after transplanting, showing almost 100% control of purple nutsedge. Tuber of purple nutsedge composed of 61.83% of moisture, 31.60% of carbohydrates, 4.03% of crude protein, 1.57% of crude fat and 0.97% of crude ash.