Pollution of agricultural soil by alkaline salts, such as Na2CO3, is a critical and long-lasting problem in cultivable land. The aim of the study was to examine the putative role of citric acid (CA) in alleviating Na2CO3-stress in alfalfa. In this study, Na2CO3 significantly induced leaf chlorosis, inhibited plant growth and photosynthesis related parameters, increased hydrogen peroxide (H2O2) and reduced major antioxidant enzymes (SOD ,CAD, APX) in alfalfa. However, the presence of CA these negative effects of Na2CO3-stress largely recovered. Interestingly, expression of antioxidant and ion transporter genes (Fe-SOD, CAT, APX, DHAR and NHX1) involved in Reactive oxygen species (ROS) homeostasis and oxidative stress tolerance in alfalfa. These findings suggest that CA-mediated Na2CO3 stress alleviation is an ecofriendly approach that would be useful to local farmer for alfalfa and other forage crop cultivation in alkaline soils.

본 연구는 네 가지 서로 다른 비음처리구(무처리, 25%, 50%, 70% 차광처리)에서 2년간 생육한 잔대 묘목의 광합성 특성을 분석하였다. 엽록소 a, b 함량과 마찬가지로 총 엽록소 함량은 처리구간에서 유의 적인 차이가 나타나지 않았다. 광합성능력은 50%와 75% 차광처리구 보다 무처리구와 25% 처리구가 더 높은 것으로 나타났다. 무처리구(전광조건) 하에서 생육한 잔대 묘목은 가장 높은 광합성 능력, 기공전도도, 엽육 내 CO2 농도를 나타냈으며, 수분이용효율은 50%와 75% 차광처리구가 무처리구(전광조건) 보다 더 높은 것으로 나타났다.

8일간 생장한 보리 유식물에 72시간 동안 dimethipin을 처리하면서 엽록소 함량의 변화와 광합성적 전자전달 활성을 측정하였다. 10/sup -3/M dimethipin을 72시간 처리한 경우 엽록소 함량이 33% 감소하였다. 이에 비해 7일간 암소에서 생장시킨 후 dimethipin을 처리한 보리 유식물은 녹화 48시간에 10/sup -4/M에서 대조구에 비해 43% 엽록소 함량이 감소하였으며, 엽록소 a/b 비율이 증가하였다. 24시간의 dim

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

This study was performed to investigate the physiological responses of Oplopanax elatus by water condition.Drought stress was induced by withholding water for 26 days. The results show that PN max, SPAD, gs, E and Ci weresignificantly decreased with decreasing of soil moisture contents. However, AQY and WUE were decreased slightly only at26 day. This implies that photosynthetic rate is reduced due to an inability to regulate water and CO₂exchange through thestomatal. According to JIP analysis, ΦPO, ΨO, ΦEO and PIABS were dramatically decreased at 21 day and 26 day, whichreflects the relative reduction state of the photosystem II. On the other hand, the relative activities per reaction center suchas ABS/RC, TRo/RC were significantly increased at 26 day. Particularly, Dio/RC and DIo/CS increased substantially underdrought stress, indicating that excessive energy was consumed by heat dissipation. These results of chlorophyll a fluores-cence show that the sensitivity changes photosystem II activity. Thus, according to the results, O. elatus was exhibited astrong reduction of photosynthetic activity to approximately 10% soil moisture contents, and JIP parameters could be usefulindicator to monitor the physiological states of O. elatus under drought stress.

This study was conducted to investigate the changes of chlorophyll contents, chlorophyll fluorescence, photosynthetic parameters, and leaf growth of Synurus deltoides under different shading treatments. S. deltoides was grown under non-treated (full sunlight) and three different shading conditions (Shaded 88~93%, 65~75%, and 45%~55%). Light compensation point (Lcomp), dark respiration (Dresp), maximum photosynthesis rate (Pnmax), photo respiration rate (Presp), carboxylation efficiency (Φcarb), and photochemical efficiency were decreased with increasing shading level; However, CO2 compensation point (CO2 comp), total chlorophyll content, and specific leaf area (SLA) were shown the opposite trend. S. deltoides under 88~93% treatment showed the lowest photosynthetic activity such as maximum photosynthetic rate (Pnmax), photochemical efficiency, and CO2 compensation point (CO2 comp). Therefore, photosynthetic activity will be sharply decreased with a long period of 8~12% of full sunlight. With the shading level decreased, carotenoid content and non-photochemical fluorescence quenching (NPQ) increased to prevent excessive light damage. This result suggested that growth and physiology of S. deltoides adapted to high light intensity through regulating its internal mechanism.

Brassica napus L. (Brassicaceae), is one of major oilseed crops commonly cultivated cereal-growing areas after the rice harvest in Asia countries, has recently focused much attention as its seed is the primary source for bio-diesels. In rapeseed growing regions of South Korea, typical double-cropping regions are constantly or periodically received with poorly drained soil condition or encountered dried soil condition during the reproductive stage. This study was conducted on rapeseed plants subjected to both waterlogging and drought conditions for 4 days to investigate responses in physiological characteristics, fatty acid compositions and yield performances at reproductive stage. The treatments were thus as follows: (1) control normally irrigated, (2) waterlogging treatment were flooded by placing their pots inside larger plastic pots filled with tap water with a 2-cm water layer over soil surface, (3) drought treatment was not irrigated. For recovery period, rapeseed plants subjected to waterlogging for 4 days were drained after waterlogging, and irrigated daily as control. Drought treatment after recovery period was irrigated daily as control. Rate of photosynthesis and stomatal conductance of waterlogging and drought treated plants significantly decreased within 4 days. For recovery period, stomatal conductance and photosynthetic rate of the waterlogged and drought treated plants occurred level similar to that of the controls by 2 days after recovery period. Fatty acid compositions of the both waterlogging and drought treated plants did not affect, but yield performances of the waterlogging treatment significantly decreased. These results suggest that both waterlogging and drought conditions for 4 days did not influence fatty acid compositions, but affected yield performance at final harvest.

큰봉의꼬리, 골고사리, 손고비 등 자생상록양치식물 3종을 실내공간으로 도입이 가능한지 살펴보고자 현재 실내조경공간에서 가장 많이 설정한 100lux에서 2,000lux까지의 광도범위에서 살펴본 생육 및 광합성 활성의 변화는 다음과 같다. 첫째, 큰봉의꼬리의 경우 고사율이 없어 100lux에서도 어느정도 생육은 가능하였지만 전반적인 원할한 생육은 광도가 높을수록 우월하였으며 엽색발현이나 관상가치를 살펴볼 때, 1,000lux에서 가장 우월하였으며 2,000lux의 경우 잎 가장자리가 마르거나 황변화하여 관상가치가 오히려 1,000lux보다 저조하여 형광등으로 조명을 설치할 경우 1,000lux가 가장 적합한 광도임을 알 수 있었다. 둘째, 골고사리의 경우 식물의 일부 또는 전체가 고사하여 공시식물 중 생육상태가 가장 저조하였으며 원할한 생육 및 관상가치는 1,000lux에서 가장 양호하였다. 셋째, 손고비의 경우 광도가 높을수록 생육이 원할함을 알 수 있었는 데 엽색의 발현 및 엽수에 따른 식물의 관상가치를 고려해 볼 때, 2,000lux보다 1,000lux에서 더 좋음을 알 수 있었다 이상 공시식물에 있어 생육이 가능한 광도는 차이가 있었지만 원할한 생장 및 관상가치를 높일 수 있는 최상의 적정광도는 1,000lux임을 알 수 있었다.본 연구는 현재 실내공간에 도입되고 있는 대부분의 식물이 외래종임을 감안할 때 우리 자생식물소재를 개발하고 활성화시켜야 하는 측면에서 의미가 있었다고 본다 하지만 식물소재구입의 어려움에 따라 3종만을 한정적으로 구입하여 광도에 따른 도입여부를 살펴보는 연구의 한계가 있었고 관상가치 및 식물의 미적 균형감을 결정하는에 있어서 엽수와 엽색의 변화가 가장 중요한 요소임을 감안할 때 향후 광질에 따른 연구를 비롯하여 다양한 측면에서 자생식물의 활용방안에 대한 활발한 연구가 이루어져야할 것으로 판단된다.

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.

약용 식물의 추출액이 자가영양배양세포의 광합성전자전달계에 미치는 영향을 조사하기 위해 9종의 약용식물 추출액으로부터 종자발아, PA세포의 엽록소 억제정도, DCIP의 환원율, 세포 생존율, 광계 I의 전자전달활성, 단백질에 미치는 영향을 조사한 결과는 다음과 같다. 1. 식물의 추출액을 농도별로 처리하였을 때 10％ 처리시 전 식물체에서 상추의 발아억제 현상을 나타내었고, 특히 백두옹과 초오 추출물 10％ 처리시는 100％ 억제를 나타내었다. 2. 백두옹의 증류수 및 MeOH 추출액을 PA세포에 처리한 경우 엽록소의 생성을 100％ 억제 하 였다. 이는 광합성 전자전달 저해제로 알려진 DCMU 10-3M 처리와 동일한 억제 효과였다. 3. PA세포에 추출물 처리시 백두옹이 힐반응 억제가 가장 컸으며, 세포 생존력은 가장 낮았다. 4. 광합성 산소발생은 반하, 독활, 백두옹, 만형자 추출액 처리시 14-77％ 억제되었고, 특히 PA 세포 2ml 반응액에 백두옹 추출물 60rl 처리시 50％ 산소발생 억제를 나타내었다. 5. 추출액을 PA 세포에 처리한 후 단백질을 추출하여 SDS-PAGE를 이용하여 조사한 결과 대조구에 비하여 백두옹 추출물 10％ 처리에서 14KD, 31KD, 41KD, 53KD, 73KD의 밴드가 나타나지 않았다.