• 한국환경농학회지
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• 제13권3호
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• pp.373-385
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• 1994

Resistance to paraquat (1,1'-dimethyl-4,4'-bipyridilium ion) has developed in 12 species of 8 genera to which paraquat has been applied 6 to 10 times per year for 5 or more years. In recent years, tolerance to paraquat has been found in Rehmannia glutinosa (Gaertn.) Liboch. ex Fisch. & Mey. which has never been applied with any herbicides involving paraquat. In this review, we differentiate the terms, resistance and tolerance, on the basis of the paraquat-exposure history. Five hypotheses have been evaluated in several species as potential mechanisms of paraquat resistance and/or tolerance. In a species, the mode of action may be due to 1) reduced quantities of paraquat absorbed through the leaf surface, 2) detoxification of paraquat caused by the enhanced paraquat-metabolic activity, 3) rapid sequestration reducing level of paraquat at the site of action in chloroplast, 4) alteration of site of action in photosystem I resulting in interruption of electron transport to paraquat, and 5) rapid enzymatic detoxification of superoxide and other toxic forms of oxygen.

• 한국잡초학회지
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• 제6권2호
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• pp.191-200
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• 1986

1. Paraquat에 대(對)한 식물체(植物體)의 반응(反應)은 상이(相異)하며 감수성(感受性) 정도(程度)에 큰 차(差)가 인정(認定)되었다. injury, discooration, leaf area 및 leaf dry weight 등(等)으로 보아 Kwanggyo, Milyang 등의 콩 품종(品種)은 Hood나 $D_4$에 비(比)하여 내성(耐性)을 보였다. Paraquat에 대(對)한 옥수수품종간(品種間)의 반응폭(反應幅)은 아주 좁았다. 2. 밭에 우점잡초(優占雜草)인 바랭이, 쇠비름, 강아지풀은 paraquat에 감수성(感受性)인데 비(比)하여 마디풀, 명아주, 반하 등(等)은 저항성(抵抗性)을 나타내어 저항성원(抵抗性源)을 제공(提供)하였다. 3. Paraquat의 무독화(無毒化)에 관련하는 peroxidase의 활성(活性)은 Kwanggyo에서 높았으나 무처리(無處理)와 차이(差異)가 작았다. Peroxidase의 동위효소(同位酵素)는 Kwanggyo에 6개(個), Hood에 4개(個)였으며 paraquat을 처리(處理)해도 Kwanggyo의 pattern의 거의 변화(變化)가 없으니 Hood에는 다소(多少) 변화(變化)가 인정(認定)되었다. 4. paraquat에 대(對)한 식물체(植物體) 저항성(抵抗性) mechanism인 superoxide dismutase의 활성(活性)은 paraquat 100ppm 처리후(處理後) 48시간(時間)째 Kwanggyo는 48.6 units/$m\ell$, Hood는 34.2 units/$m\ell$이고 무처리(無處理)는 Kwanggyork 33.0 units/$m\ell$, Hoodsms 34.5 units/$m\ell$로서 SOD의 활성차(活性差)가 감수성(感受性)의 차(差)를 발현(發現)시켰다고 사료(思料)된다. 5. paraquat의 농도(濃度)가 증가(增加)할수록 카루스의 증식(增殖)이 크게 억제(抑制)되었으며 100ppm 처리(處理)에서 Kwanggyo 69.4%, Hood는 92.4%의 억제(抑制)를 보여 Hood가 Kwanggyo보다 약(約) 1.5(培) 감수성(感受性)을 나타내어 superoxide dismutase와 더불어 콩 품종간차(品種間差)를 잘 설명(說明)해 주고 있다.

• 한국작물학회지
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• 제52권3호
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• pp.264-273
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• 2007

In order to examine the cross-tolerance of two chilling-tolerant cultivars (Donganbyeo and Heukhyangbyeo) and two chilling-susceptible cultivars (Hyangmibyeo and Taekbaekbyeo) to salt, paraquat, and drought, changes of physiological response and antioxidant enzymes were investigated. The seedlings were grown in a growth chamber until the 4-leaf stage. The seedlings were exposed to chilling at $5^{\circ}C$ for 3 days. For drought treatment, the seedlings were subjected to drought by withholding water from plants for 5 days. For paraquat study, plants were sprayed with $300{\mu}M$ paraquat. For the salt stress, the seedlings were transferred to the Hoagland's nutrient solution containing 0.6% (w/v) NaCl for 4 days. Chilling-tolerant cultivars showed cross-tolerant to other stresses, salt, paraquat, and drought in physiological parameters, such as leaf injury, chlorophyll a fluorescence, and lipid peroxidation. The baseline levels of antioxidative enzyme activities, catalase (CAT) and peroxidase (POX) activities in chilling-tolerant cultivars were higher than in the chilling-susceptible cultivars. However, there were no differences in ascorbate peroxidase (APX) and glutathione reductase (GR) activities between chilling-tolerant and -susceptible cultivars in untreated control. CAT activity in chilling-tolerant cultivars was higher than that in chilling-susceptible cultivars during chilling, salt, and drought treatments, but not during paraquat treatment. However, other antioxidative enzymes, APX, POX, and GR activities showed no significant differences between chilling-tolerant and -susceptible cultivars during chilling, salt, paraquat, and drought treatments. Thus, it was assumed that CAT contribute to cross-tolerance mechanism of chilling, salt, and drought in rice plants.

• 한국잡초학회지
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• 제32권3호
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• pp.211-221
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• 2012

선행연구를 통해 18종의 호박 품종에 대한 엽위별 paraquat에 대한 내성 반응을 조사한 결과, 1엽<2엽<3엽<4엽 순이었다. 이들 품종 중에서 엽령간 뚜렷한 내성차이가 있는 중앙애호박의 경우 4엽은 1엽에 비해 paraquat에 대해 3배 이상의 높은 내성을 보였다. 또한 이들 4엽의 물 추출물과 paraquat를 혼용하여 옥수수 경엽에 처리시 paraquat 약해를 경감시켰다. 따라서 본 연구는 paraquat 약해를 경감시키는 물질이 어린 호박잎에 존재하는지를 알아보기 위하여 수행하였다. MeOH 추출물보다 물 추출물에서 paraquat 활성경감이 더 높아서 물 추출물을 실리카겔과 Sephadex LH-20 칼럼크로마토그래피와 TLC, HPLC를 이용하여 paraquat 활성 경감 효과를 보이는 순수물질을 얻어 NMR을 통해 분석한 결과 malic acid로 추정되었다. 따라서 malic acid가 paraquat 활성경감 물질여부를 확인하기 위하여 malic acid와 paraquat를 옥수수에 동시 처리하였다. 처리 후 1일째 $100{\mu}M$ paraquat를 단독으로 처리한 경우 옥수수 잎 피해가 62% 발생하였으나 $100{\mu}M$ paraquat에 malic acid를 각각 0.1, 0.3, 0.5 및 1% 혼용처리한 경우 잎 피해가 전혀 발생하지 않았다.

• Journal of Crop Science and Biotechnology
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• 제10권1호
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• pp.8-12
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• 2007

All accessions of Rehmannia glutinosa show the unique characteristic of intrinsic tolerance to paraquat. The higher level of endogenous superoxide dismutase(SOD) activity and its increase upon paraquat treatment indicated the involvement of SOD in the tolerance mechanism to paraquat in R. glutinosa. In this study, we examined the isoform-specific response of SOD to oxidative stresses and hormones. Six SOD isoforms were found in the leaf, and they were identified as two MnSODs(named MnSOD I and MnSOD II, in order of increasing mobility), one FeSOD and three Cu/ZnSODs(named Cu/ZnSOD I, Cu/ZnSOD II, and Cu/ZnSOD III, in order of increasing mobility). MnSOD I, MnSOD II, FeSOD, Cu/ZnSOD I, Cu/ZnSOD II, and Cu/ZnSOD III, contributed to 4, 11, 7, 15, 30, and 32% of the total SOD activity, respectively. Total SOD activity levels in the leaf were increased by 4, 24, and 21% by paraquat, salicylic acid(SA), and yeast extract(YE), respectively, but little by ethephon. Six SOD isoforms responded differentially to these stresses and hormones. The activities of all the isoforms were increased by YE and SA except that of MnSOD I which was decreased by SA. The activities of MnSOD I, FeSOD, and CuZnSOD I were increased by paraquat. These results suggest that amelioration of oxidative stresses by SOD is fine-tuned by the differential expression of isoforms in R. glutinosa.

• 한국잡초학회지
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• 제15권1호
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• pp.1-12
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• 1995

제초제(除草劑) paraquat는 대표적(代表的)인 비선택성(非選擇性) 제초제(除草劑)로서 식물체(植物體)내에서 광합성(光合成)의 전자(電子)흐름을 방해 하여 독성(毒性)을 나타낸다. 본(本) 실험(實驗)은 paraquat를 뿌리를 통해 흡수시킨 후 잡초종(雜草種)들의 반응(反應)을 통하여 조사하였다. 1. Paraquat에 대한 저항성(抵抗性)은 식물종의 생태적(生態的) 특성(特性)과 깊은 관계가 있었다. 일반적으로 일년생(一年生)보다는 다년생(多年生)이나 월년생식물(越年生植物)의 저항성(抵抗性)이 크게 나타났다. 2. 꿀풀과와 석죽과 십자화과의 식물들이 비교적 paraquat에 저항성(抵抗性)을 보였으며, 반면에 화본과의 식물들이 비교적 감수성(感受性)을 나타내었다. 3 꿀풀과의 쥐깨풀은 강한 저항성을 나타냈고, 대부분의 종(種)이 감수성(感受性)을 보인 화본과와 국화과에 있어서도 참새피와 지칭게 등은 강한 저항성(抵抗性)을 나타냈다. 4. Paraquat는 발아(發芽)에도 영향을 주였으나, 발아(發芽)시기의 반응(反應)과 성식물(成植物)의 반응(反應)과는 일치하지 않는 경향이었다.

• BMB Reports
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• 제37권5호
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• pp.618-624
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• 2004

All members of R. glutinosa show the unique characteristic of intrinsic tolerance to paraquat (PQ). Antioxidant enzymes have been proposed to be the primary mechanism of PQ resistance in several plant species. Therefore, the antioxidant enzyme systems of R. glutinosa were evaluated by comparatively analyzing cellular antioxidant enzyme levels, and their responses of oxidative stresses and hormones. The levels of ascorbate peroxidase (APX), glutathione reductase (GR), non-specific peroxidase (POX), and superoxide dismutase (SOD) were 7.3-, 4.9-, 2.7- and 1.6-fold higher in PQ-tolerant R. glutinosa than in PQ-susceptible soybeans. However, the activity of catalase (CAT) was about 12-fold higher in the soybeans. The activities of antioxidant enzymes reduced after PQ treatment in the two species, with the exception of POX and SOD in R. glutinosa, which increased by about 40%. Interestingly, the activities of APX, SOD and POX in R. glutinosa, relative to those in soybeans, were further increased by 49, 67 and 93% after PQ treatment. The considerably higher intrinsic levels, and increases in the relative activities of antioxidant enzymes in R. glutinosa under oxidative stress support the possible role of these enzymes in the PQ tolerance of R. glutinosa. However, the relatively lower levels of SOD versus PQ tolerance, and the mixed responses of antioxidant enzymes to stresses and hormones, suggest a possible alternative mechanism(s) for PQ tolerance in R. glutinosa.

• 한국잡초학회지
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• 제15권3호
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• pp.224-231
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• 1995

Paraquat에 대한 잡초종(雜草種)의 다양한 반응(反應)은 여러 가지 요인에 의한다. Paraquat에 대하여 내성종(耐性種)과 감수성종(感受性種)은 가시적(可視的)인 피해율(被害率)의 차이(差異)를 비롯하여 체내(體內) 물질(物質) 변화(變化)의 차이(差異)는 물론 체내(體內) 효소(酵素) 활성(活性)의 차이(差異) 등을 나타났다. 내성종(耐性種)은 paraquat에 의한 photosystem II의 활성(活性) 저하(低下) 정도가 감수성종(感受性種)보다 작았으며, 지질(脂質)의 과산화(過酸化) 정도(程度) 역시 내성종(耐性種)에서 낮았다. 체내(體內) 물질(物質) 중 엽록소(葉綠素)는 paraquat에 의해 줄어들었으나 환원당(還元糖)의 경우는 paraquat의 농도(濃度)가 높아질수록 증가하였다. 항산화제(抗酸化劑)인 glutathione의 경우 처리농도(處理濃度)가 증가함에 따라 함량(含量)이 증가하는 경향이었으나 내성종(耐性種)과 감수성종(感受性種)의 구분은 뚜렷하지 않았다. 항산화효소(抗酸化酵素)인 glutathione reductase의 활성(活性)은 내성종(耐性種)에서 높게 나타났으며, superoxide dismutase의 경우는 paraquat의 처리농도(處理濃度)가 증가함에 따라 그 활성(活性)이 증가하였다. 체내대사(體內代謝)의 주요 효소(酵素)들인 catalase, NADPH-cytochrome c reductase, malate dehydrogenase의 활성(活性)은 catalase의 경우 저농도(低濃度)의 paraquat에 의해서는 활성(活性) 저하(低下) 정도(程度)가 낮은 반면 나머지 두 효소(酵素)는 저농도(低濃度)에서부터 급격한 활성저하(活性低下)가 나타났다.

• Plant Biotechnology Reports
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• 제5권3호
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• pp.225-234
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• 2011

Arabidopsis mutants with T-DNA insertion in seven calmodulin genes (CAM) were used to determine the specific role of CAM in the tolerance of plants to oxidative stress induced by paraquat and hydrogen peroxide ($H_2O_2$) treatments. Arabidopsis calmodulin mutants (cam) were screened for seedling growth, seed germination, induced oxidative damage, and levels of ${\gamma}$-aminobutyric acid (GABA) shunt metabolites. Only the cam5-4 and cam6-1 mutants exhibited an increased sensitivity to paraquat and $H_2O_2$ during seed germination and seedling growth. In response to treatments with $3{\mu}M$ paraquat and 1 mM $H_2O_2$, only the cam5-4, cam6-1 mutants showed significant changes in malonaldehyde (MDA) levels in root and shoot tissues, with highly increased levels of MDA. In terms of the GABA shunt metabolites, GABA was significantly elevated in root and shoot tissues in response to the paraquat treatments in comparison to alanine and glutamate, while the levels of all shunt metabolites increased in root tissue but not in the shoot tissue following the $H_2O_2$ treatments. GABA, alanine and glutamate levels were significantly increased in root and shoot of the cam1, cam4, cam5-4, and cam6-1 mutants in response to paraquat (0.5, 1 and $3{\mu}M$), while they were increased only in the root tissue of the cam1, cam4, cam5-4, and cam6-1 mutants in response to $H_2O_2$ (200 and $500{\mu}M$, 1 mM). These data show that the cam5-4 and cam6-1 mutants were sensitive to the induced oxidative stress treatments in terms of seed germination, seedling growth, and oxidative damage. The accumulation of GABA shunt metabolites as a consequence of the induced oxidative stress treatments (paraquat and $H_2O_2$ treatments) suggests that the GABA shunt pathway and the accumulation of GABA metabolites may contribute in antioxidant machinery associated with reactive oxygen species and in the acquisition of tolerance in response to induced oxidative stress in Arabidopsis seedlings.

• 생명과학회지
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• 제14권4호
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• pp.614-619
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• 2004

This study was undertaken to investigate the different responses of cultured plant cells to paraquat treatment and nucleus-DNA damage in relation to enzyme activity of superoxide dismutase (SOD). Furthermore, this study was also carried out to understand the antioxidative mechanism of plant cells to environmental stress. We selected two different species of plant cultured cells, Ipomoea batatas as high-SOD species and Lonicera japonica as low-SOD species. The total activity and specific activity of SOD in a chlorophyllous cell of I. batatas were 3,736 unit/gㆍfresh weight and 547 unit/mgㆍprotein, respectively, and those in L. japonica were 23 unit/gㆍfresh weight and 13 unit/mgㆍprotein, respectively SOD activity in chlorophyllous I. batatas cells reached its maximum level at 10 to 15 days after subculture, whereas that in L. japonica remained at a very low SOD level during the whole period of subculture. In comparison to L. japonica, I. batatas, a high-SOD species, showed high tolerance to paraquat 10 and 50 mg/l treatment in terms of cell viability and electrolyte leakage. Based on the result of comet assay, the nucleus-DNA damage of two species by paraquat 50 mg/l treatment was not significantly different. However, I. batatas cells repaired their damaged DNA more effectively than the cells of the low-SOD species, L. japonica.