3주간 정상적으로 생장한 닭의장풀을 Hoagland 용액 (대조구, 100 μM Cd/sup 2+/, 100 μM Cd/sup 2+/ + 100 μM ABA, 100 μM Cd/sup 2+/+50 mM KCl)에서 1주간 수경재배 한 후 생장, 엽록소 함량, 엽록소 형광, 수분 스트레스와 Cd/sup 2+/의 축적을 조사하여 Cd/sup 2+/ 축적과 식물의 생리적 반응과의 연관성을 찾고자 하였다. 식물의 생장에서 Cd/sup 2+/과 Cd/sup 2+

3주간 정상적으로 생장한 닭의장풀을 Hoagland용액 (± 100 μM Cd2+, 100 μM Cd2++10 μM IAA,100 μM Cd2++100 μM IAA,100 μM Cd2+ +1 μM IAA)에서 3주간 수경재배 한 후 생장, 기공개폐, 엽록소 함유량, 엽록소 형광 및 수분퍼텐셜을 조사하였다. Hoagland용액에 Cd2+ 처리시 3주 동

3-weeks old Commelina was transferred to and grown in Hoagland solution (± 100 μM Cd2+, 100 μM Cd2+ ＋ 100μM Ca2+, 100 μM Cd2+ ＋ 200 μM EGTA) for two weeks and then a number of physiological activities

3주간 생장한 닭의장풀을 Hoagland용액에서 3주 동안 수경배양하면서, 100μM Cd2+과 100μM salicylic acid(SA)를 처리한 후 성장, 엽록소 함유량, 수분퍼텐셜, 엽록소 형광, 광합성능 및 기공전도도를 조사하였다. Hoagland용액에 Cd2+ 처리시 3주 동안 2.1cm생장했으나, 대조구는 7.2cm생장했다. 반면에 Cd2+ + SA 처리구는 1주 동안 0.7cm자랐으며, 2주 후에는

3주간 정상적으로 생장한 닭의장풀을 Hoagland용액(±100μM Cd2+,100μM Cd2++100μM Ca2+, 100μm Cd2++200μM EGTA) 에서 1주 동안 수경 배양한 후 Cd2+ 처리시 Cd2+ 흡수와 생장에 미치는 Ca2+의 영향을 조사하였다. EGTA처리는 Cd2+ 수송에 영향을 주지 않았지만 생장 및 생체량에서Cd

3주간 생장한 닭의장풀을 Hoagland용액 (±100μM Cd2+ 또는 100μM Cd2++100μM SA)에서 4일 동안 수경 재배한 후 Cd2+ 및 살리실릭산(SA) 처리시, 닭의장풀의 뿌리와 분리 표피에서의 Cd2+ 농도와 nonprotein-SH 합성을 측정하였다. Cd2+ 처리구에서는 98μM Cd2+/g.fr.wt이 검출되었다. 이는 대조구에 비해

Cd2+이 닭의장풀의 분리표피와 온전한 잎의 기공개폐에 미치는 영향을 조사하였다. Cd2+을 분리표피에 처리하였을 때 기공열림이 촉진되었다. 100μMCd2+처리시 기공은 8.38μm까지 열렸으나, 대조구는 3.74μm였다. 대조구의 기공 크기는 일반적으로 작게 열렸다. 따라서, 분리표피가 생리적으로 건강한지를 조사하기 위해, 살리실릭산(SA)과 앱시스산(ABA)을 분리표피

Cd2+이 닭의장풀의 엽록소 함유량, 기공 크기, 수분퍼텐셜, 이온 수송에 대한 효과와 기관내의 카드뮴의 축적에 대하여 조사하였다. 3주간 성장한 닭의장풀을 Hoagland용액(±5mM Cd2+)에서 4일 동안 수경배양하였다. 카드뮴은 식물의 뿌리, 줄기 그리고 잎 등 모든 기관에 축적되었다. 뿌리로부터의 거리와 잎의 나이 등이 카드뮴 분포를 결정짓는 가장 중요한 요소였다. 대부분의 Cd2+이 뿌리로부터 가장 인접한 성숙한 첫 번

살리실릭산(SA)이 닭의장풀의 잎의 생장, 엽록소 함량, 광합성능, 기공전도도에 미치는 영향을 조사하였다. Hoagland 용액에 SA를 처리한 후 3주 동안 배양한 닭의장풀은 잎의 길이, 너비, 면적이 크게 감소하였다. 1 mM SA를 1, 2주 처리 시에 엽면적 생장이 약 10%억제되었으며, 3주 째에는 22%억제하였다. SA는 또한 2주 째는 47%그리고 3주 째는 53%엽록소 함량을 감소시켰다. SA를 처리한 샘플의 엽록소 a/b는 3주 째에 약

닭의장풀(Commelina communis L., Dayflower) 추출물의 미백효능을 확인하기 위하여 B16 melanoma 세포를 이용하여 melanin 생성에 관련된 다양한 실험을 실시하였다. 닭의장풀 추출물은 버섯 tyrosinase 활성 실험에서 저해 효과를 보이지 않았으나, melanin 생성 저해효과를 나타내었다. B16-F10 멜라노마 세포를 이용한 활성시험 결과에서, 닭의장풀 추출물은 1,000 µg/mL의 농도에서 약 32 %의 멜라닌 생성을 억제하였으며, 세포내 티로시나제 활성 억제 능도 우수하여 닭의장풀 추출물 250 µg/mL 이상의 농도에서 50 % 이상의 저해 효과를 보였다. 추출물의 melanin 생성 기작에 대한 영향을 조사한 결과, melanin 합성의 key protein인 tyrosinase 발현의 우수한 저해 능력을 보였고, tyrosinase related protein-1 (TRP-1)의 발현 억제와 tyrosinase related protein-2 (TRP-2)의 N-glycosylation 억제를 통해 melanin 합성이 억제되는 것으로 분석되었다. 따라서 닭의장풀 추출물은 melanin 합성에 필수적인 효소(tyrosinase, TRP-1)의 발현 저해 및 TRP-2의 N-glycosylation 억제를 통해 미백 효과를 나타내는 것으로 확인되었으며, 이에 따라 본 추출물은 melanin 합성의 효소 경로를 저해하는 미백 소재로 활용할 수 있을 것으로 사료된다.

To investigate the influence of the mesophyll cells on stomatal opening in response to white light, the segments of isolated epidermis were transferred on partly exposed mesophyll cells of a leaf and stomatal apertures were measured. Transferring the isolated epidermis on partly exposed mesophyll cells of a leaf caused a marked increase on stomatal apertures while stomata in isolated epidermis incubated in MES buffer hardly opened. Mesophyll infiltration with photosynthetic inhibitors (DCMU, DCCD, NaN3) was performed to elucidate the correlation between stomatal apertures and the degree of photosynthetic activity. It was found that transferring the isolated epidermis on partly exposed mesophyll cells of a leaf caused an increase of stomatal apertures depending on the degree of photosynthetic activities. In NaN3 infiltrated leaf discs, transferring the fresh isolated epidermis on partly exposed mesophyll cells of a leaf showed no significant effect, but a slight increase on stomatal apertures. Isolated epidermis alone did not respond to the light properly, but if it was closely contacted with mesophyll cells, the stomata regained the ability of the light response. Therefore, it could be suggested that stomatal apertures were related with the degree of photosynthetic activity in the mesophyll cells.

Three-week old Commelina communis was transferred and grown in Hoagland solution containing 100μM Cd2+, 100μM Cd2++100μM kinetin, 100μM Cd2++100μM zeatin and 100μM Cd2++200μM zeatin for 7 days, and then a number of physiological activities were investigated. In control, the length of the stem of plants was increased to 4.7cm, but in Cd2+, Cd2++kinetin, Cd2++100μM zeatin and Cd2++200μM zeatin treatments, the growth of plants were increased to 1.5cm, 2.1cm, 3.9cm and 4.3cm, respectively. In the treatments of Cd2+, Cd2+ +kinetin, Cd2++100μM zeatin and Cd2++200μM zeatin, total chlorophyll contents were reduced to 26%, 24%, 15% and 3%, respectively, on the contrast to the control. In chlorophyll fluorescence experiments, Fv/Fm ratios were also reduced to 44%, 21%, 17% and 5% in the light intensity of 2100μmole E m-2s-1 by Cd2+, Cd2++ kinetin, Cd2++100μM zeatin and Cd2++200μM zeatin treatments on the contrast to the control. Water stresses were increased to 2.6, 1.7 and 1.2 times by Cd2+, Cd2++kinetin and Cd2++100μM zeatin. On the other hand, combination of Cd2++200μM zeatin reduced water stress to 0.12%. In Cd2+ accumulation experiments Cd2+ transports were inhibited to 33%, 48% and 70% by Cd2++kinetin, Cd2++100μM zeatin and Cd2++200μM zeatin. Therefore, it could be concluded that zeatin clearly reduced the toxicities of Cd2+ by reducing the absorption of Cd2+.

3-weeks old Commelina was transferred to and grown in Hoagland solution (Control, 100μM Cd2+, 100μM Cd2++100μM IAA, 100μM Cd2++100μM IAA+2 mM sucrose) for 3 weeks and then the effects of indole acetic acid (IAA) on the accumulation of Cd2+ and growth of Cd2+-treated Commelina were investigated. In the treatment of Cd2+, Cd2+ was uptaked to 1.74, and 51.36 μg/g frwt. at the first week, but for three weeks, 0.51 and 34.53 μg/g frwt. in leaf and stem respectively. When IAA was treated along with Cd2+, Cd2+ was uptaked to 0.18 and 8.63 μg/g frwt. at the first week, and for the incubation of 3 weeks, 0.51 and 45.0 μg/g frwt. in leaf and stem. In case of Cd2++IAA+sucrose, Cd2+ was uptaked to 1.45 and 18.33 μg/g frwt. at the first week, but for 3 weeks, 0.51 and 25.45 μg/g frwt. in leaf and stem. Likewise Cd2+ uptake, the growth was also affected by Cd2+ and IAA. During the incubation of 3 weeks, Cd2+ reduced the stem growth about 8% in all weeks, but the treatment of IAA recovered the inhibition of stem growth caused by Cd2+ to the degree of the control Therefore, it could be concluded that IAA altered the pattern of Cd2+ uptake and the growth which were supposed to change Cd2+ toxicity.

The mechanism of stomatal closing in response to O_3 was indirectly investigated by using H_2O_2 which is the intermediate product of O_3 metabolites. Stomata in epidermal strips close in response to H_2O_2. The effect of H_2O_2 on stomatal closing was dependent on the concentration of H_2O_2. 10 ppm H_2O_2 showed a clear effect on stomatal closing and 1000 ppm H_2O_2 induced complete stomatal closing after the treatment of 3 hours. Stomatal closing by H_2O_2 in intact leaf was also observed by measuring the diffusion resistance with porometer. It was found that the stomatal closing by H_2O_2 was not mediated by Ca^2+, and that was a different result observed in stomatal closing by water stress. Reversely, Ca^2+, showed a great inhibition on stomatal closing. The leakage of K^+ in epidermal strips was doubled in response to H_2O_2 when it was campared to the control. 10 ppm H_2O_2 decreased photosynthetic activity. Fv/Fm representing the activity of Photosystem Ⅱ was reduced about 4 % in 10 ppm H_20_2 and 8 % in 100 ppm H_2O_2 in the treatment of 1.5 hour. However, stomatal closing by 10 ppm H_2O_2 was reduced about 56 %. Accordingly, it can be suggetsted that stomatal closing by H_2O_2 is related with the decrease of photosynthetic activity, but it was chiefly induced by the change of the membrane permeability.

ABA and SA showed different effect on stomatal closing on same condition. The addition of 1 mM salicylic acid to fully opened stomata resulted in a significant reductionn of 22 % in stomatal aperture. However, 1 mM ABA reduced 73 % of stomatal aperture. The light absorption spectra of the salicylic acid solution showed that SA was degraded within 1 hour. Therefore, SA solution was resupplied to the detached epidermis every 30 min. during incubation and it was found that even at 10 μM SA induced stomatal closing significantly. Its effect was also greatly pH dependent. The reduction of stomatal aperture caused by 1 mM SA was most effective at lower pH (pH 7.2, 5 %; pH 6.2, 40 %; pH 5.2, 78 %). Therefore, if SA was properly treated to the epidermal strips in the medium, the effects of SA on stomatal closing were similar with those of ABA.

동아(Benincasa hispida(Thunb) Cogn)와 달개비 (Commelina communis L.)의 종자, 잎 및 줄기등을 공시재료로 하여 몇가지 효소에 대한 전기영동적 특성을 비교한 결과는 다음과 같다 1. Esterase isozyme의 pattern은 band수나 Rf값에서 현저한 차이를 나타냈으며 동아의 육질에서는 단 1개의 band가 출현하였다. 2. Peroxidase isozyme은 동아의 육질에서 4개의 band가 출현하였으나, 달개비의 줄기에서는 band 가 전혀 없었다. 3. Amylase isozyme의 전기영동대는 동아의 종자 및 육질에서만 각각 1개씩 뚜렷한 band를 나타냈다.