본 연구는 절화 아이리스의 노화와 절화수명에 미치는 에틸렌의 영향과 이러한 에틸렌의 작용을 억제할 수 있는 STS 전처리의 효과에 대하여 알아보고자 수행하였다. 아이리스는 1mM STS 용액에 30분간 전처리한 후 0, 3mL·L−1 의 에틸렌에 24시간 노출시켰다. 봉오리 상태 에서 절화 아이리스의 절화수명은 STS 전처리후 에틸렌 에 노출된 것은 4.2일, 에틸렌에 노출되지 않았던 꽃은 4.6일 이었다. 반개화 상태에 수확한 아이리스의 절화수명 은 STS 전처리에서 길었다. 그러나 에틸렌 노출에 의해 서는 수명이 영향을 받지 않았다. 그러므로 절화 아이 리스는 외생 에틸렌에 민감하지 않음을 알 수 있었다. 봉 오리 상태에서 수확한 절화는 완전한 개화가 유도되지 않 고 노화가 일어나는 경우가 많으므로 어느 정도 개화가 진전된 꽃을 수확하는 것이 필요한 것으로 판단되었다.

The influences of ethylene inhibitors (AgNO3 and silver thiosulfate) and cytokinins (BAP and TDZ) on shoot regeneration from cotyledon and hypocotyl explants of B. napus cv. Youngsan were investigated. The presence of 50 μM Silver thiosulfate (STS) in shoot regeneration medium formed shoots at 60-68% after 3-4 weeks of culture, which was enhanced by 2-fold compared to that of Silver nitrate (AgNO3). Moreover, cotyledon explants were more regenerative than hypocotyls; shoots from cotyledon explants began to occur 4-5 days earlier than that of hypocotyl explants. TDZ at a concentration of 8-10 μM was effective for shoot regeneration, compared with BAP. Consequently, the optimal shoot regeneration response was observed in medium supplemented with 50 μM STS + 8 μM TDZ. In transmission electron microscopy (TEM) analysis, higher density of silver nanoparticles was shown to be accumulated widely inside the cell wall and plasmodesmata of regenerating leaf cultured in medium supplemented with AgNO3. By contrast, in the cell cultured in medium with STS, fine-grained deposits were partly observed in the surroundings of the cell wall.

The deep irrigation of rice plants brings about some beneficial effects such as reduced tiller production which results in the formation of bigger panicles, prevention of chilling injury, reduced weed growth, etc. The present study was carried out to examine the involvement of ethylene in the suppression of tiller production due to deep water irrigation in rice (cv. Dongjinbyeo). The ethylene production was induced in leaf sheath within 24 hours after the deep water irrigation and has increased even until 30 days after the treatment, recording 4.5-fold increase as compared to the shallow-irrigated rice plants. In the deep water irrigated rice plants, ethylene was accumulated to a high concentration in the air space of submerged leaf sheath as the irrigated water deterred the diffusion of ethylene out of the leaf sheath and ethylene biosynthesis was accelerated by the deep irrigation as well. The ethylene concentration recorded 35-fold increase in the deep-irrigated rice plants for 35 days. The tiller production was reduced significantly by the deep irrigation with water, the tiller bud, especially tertiary tiller bud differentiation being suppressed by the deepwater irrigation treatment, whereas the rice plants deep-irrigated with solutions containing 10-5 M or 10-6 M silver thiosulfate (STS), an action inhibitor of ethylene, showed the same or even higher production of tillers than those irrigated shallowly with water. This implies that the ethylene is closely linked with the suppression of tiller production due to deep water irrigation. In conclusion, ethylene, which was induced by hypoxic stress and accumulated in the leaf sheath due to submergence, played a key role in suppressing the tiller production of the deepwater irrigated rice