• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.40-40
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• 2017

Rice (Oryza sativa L.) is one of major crops of Vietnam. Rice plant contains many secondary metabolites that are potent to inhibit growth of other plants. This study was carried out to find potential plant growth inhibitors from rice plants. Seven rice varieties were cultivated in the fields affiliated to Hiroshima University, Japan; Mature stems and leaves from each variety were collected, and then they were extracted with methanol, hexane, ethyl acetate, butanol, and water. Total phenolic content and total flavonoid content were the highest in ethyl acetate extract. DPPH antioxidant assay results showed that the ethyl acetate extract also had higher $IC_{50}$ value. Therefore, the ethyl acetate extracts were selected for laboratory bioassay. Results showed that the two-local variety Re nuoc and Nan chon inhibited the germination of radish and barnyard grass seedlings at the greatest levels, as compared to other cultivars. HPLC quantification indicated that the ethyl acetate extracts of Re nuoc and Nan chon rice plant parts consists of phenolic and flavonoids compounds which are potent as plant growth inhibitors. Further laboratory bioassay and field experimentation will be conducted to validate the laboratory bioassay findings.

• Journal of Microbiology and Biotechnology
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• 제19권11호
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• pp.1431-1438
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• 2009

The role of plant growth-promoting rhizobacteria (PGPR) in the phytoremediation of heavy-metal-contaminated soils is important in overcoming its limitations for field application. A plant growth-promoting rhizobacterium, Serratia sp. SY5, was isolated from the rhizoplane of barnyard grass (Echinochloa crus-galli) grown in petroleum and heavy-metal-contaminated soil. This isolate has shown capacities for indole acetic acid production and siderophores synthesis. Compared with a non-inoculated control, the radicular root growth of Zea mays seedlings inoculated with SY5 can be increased by 27- or 15.4-fold in the presence of 15 mg-Cd/l or 15 mg-Cu/l, respectively. The results from hydroponic cultures showed that inoculation of Serratia sp. SY5 had a favorable influence on the initial shoot growth and biomass of Zea mays under noncontaminated conditions. However, under Cd-contaminated conditions, the inoculation of SY5 significantly increased the root biomass of Zea mays. These results indicate that Serratia sp. SY5 can serve as a promising microbial inoculant for increased plant growth in heavy-metal-contaminated soils to improve the phytoremediation efficiency.

• 한국환경농학회지
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• 제25권3호
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• pp.268-275
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• 2006

ALA (5-aminolevulinic acid) has been proposed as a tetrapyrrole-dependent photodynamic herbicide by the action of the protoporphyrinogen IX oxidase (Protox IX). A study was conducted to determine photodynamic herbicidal effect of ALA on seedling growth of rice (Oryza sativa L.) and barnyard grass (Echinochloa crus-galli Beauv. var. oryzicola Ohwi) under dry and wet conditions. ALA effect on early plant growth of rice and barnyardgrass was greatly concentration dependant, suggesting that it promotes plant growth at very low concentration and inhibits at high concentration. No significant difference in herbicidal activity of biologically and synthetically produced ALAs on plant lengths of test plants was observed ALA exhibited significant photodynamic activity regardless of PSDIP and its duration. Significant shoot growth inhibition by ALA soaking treatment exhibited apparently, indicating that ALA absorbed through root system was translocated into shoot part of plants. ALA reduced plant heights of rice and barnyardgrass seedlings by 6% and 27%, respectively, showing more tolerant to ALA in rice under wet condition. Leaf thickness was reduced markedly by ALA with increasing of ALA concentration, due to mainly membrane destruction and severe loss of turgidity in mesophyll cells, although the epidermal was little affected. It was observed that photodynamic herbicidal activity of ALA applied by pre-and post-emergence application exhibited differently on plant species, and that the activity of ALA against susceptible plants was highly correlated with growing condition.

• 한국작물학회지
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• 제48권5호
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• pp.402-406
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• 2003

Greenhouse and laboratory studies were conducted to determine the allelopathic potentials of extracts or residues from sweet potato (Ipomoea batatas L. (Lam). The extracts applied on filter paper in a Petri dish bioassay significantly inhibited root growth of alfalfa. Aqueous leachates at 40g dry tissue $\textrm{L}^{-1}$ (g $\textrm{L}^{-1}$) from leaves showed the highest inhibition against alfalfa, and followed by stems and roots. Alfalfa root growth was significantly inhibited by methanol extracts of the same plants as the concentration increased. The effect of residue incorporation into soil on seedling growth of com, soybean, barnyard grass and eclipta was examined in the greenhouse, and results showed that the leaf residues at 200g $\textrm{kg}^{-1}$ by plant parts inhibited shoot dry and root dry weights of test plants by 60-80%. By means of HPLC, causative allelopathic substances present in plant parts of sweet potato "Sinyulmi" were identified as coumarin, trans-cinnamic acid, o-coumaric acid, p-coumaric acid, and chlorogenic acid. Total content of these compounds for leaves extracts were detected as the greatest amount in EtOAc fraction, especially trans-cinnamic acid was the greatest component. These results suggest that sweet potato plants have herbicidal potentials, and that their activities exhibit differently depending on plant parts.ant parts.

• Plant Resources
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• 제7권1호
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• pp.69-76
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• 2004

Lettuce (Lactuca sativa L.) is known to contain water-soluble substances that are biologically active. Aqueous or methanol extracts and residues from leaves of lettuce plants were assayed to determine their allelopathic effects, and the causative allelochemicals from fractions were quantified by means of HPLC analysis and bioassayed. Extracts from oven-dried leaf samples were more phytotoxic than those from freeze-dried samples. Leaf extracts of 40 g L$^{-1}$ were completely inhibitory on root growth of alfalfa (Medicago sativa L.), while root growths of barley (Hordeum vulgare L.) and soybean (Glycine max L.) were less sensitive. Early seedling growth of both alfalfa and barnyard grass (Echinochloa crus-galli) was significantly reduced by methanol leaf extracts. The major allelopathic substances analyzed by HPLC were coumarin, trans-cinnamic acid, o-coumaric acid, p-coumaric acid and chlorogenic acid. Of them p-coumaric acid was found as the greatest amount (8.9 mg 100 g$^{-1}$ ) in the EtOAc fraction; only coumarin was found in all the fractions. Hexane and EtOAc fractions of L. sativa reduced alfalfa root growth more than did BuOH and water fractions. These results suggest that lettuce had potent herbicidal activity, and that its activity differed depending on type and amount of causative compounds by fraction.

• 한국수자원학회논문집
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• 제47권10호
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• pp.973-983
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• 2014

본 연구는 밭경지 현장실험을 통해 다양한 초생대 초종을 적용하여 밭의 비점오염저감효과 분석 및 초생대에 적용 가능한 적합한 초종을 선정하고자 하였다. 경북 군위군에 위치한 면적 $1,500m^2$, 경사 5%의 밭경지를 선정하여 시험포를 조성하였으며, 시험포내에는 대조구 1개와 초생대 처리구 6개로 구성된 총 7개의 시험구를 조성하였다. 츄파, 피, 바랭이, 잔디, 톨페스큐, 켄터키블루그라스를 포함하는 6개의 초종을 선정하여 초생대 실험을 수행하였다. 현장실험 결과 대조구 대비 초생대의 유출저감효과는 6.1~77.8%였으며, 비점오염저감효과는 TS의 경우 15.6~90.3%, T-P의 경우 49.9~96.6%, T-N의 경우 6.7~91.1%를 나타내었다. 전체 오염인자 중에 초생대로 인해 전반적으로 높은 비점오염저감 효과를 나타낸 것은 TS, T-P, T-N, SS인 반면, BOD, TOC와 $NO_3^-$는 낮은 저감효과를 보였다. 비점오염저감 및 유지관리측면에서 가장 유리한 초생대 초종은 잔디로 평가되었다. 본 연구결과를 통해 우리나라 농촌지역 밭 비점오염저감을 위한 관리기법으로 초생대가 효과적으로 활용가능하리라 사료되며, 보다 장기적이고 다각적인 현장실험을 통해 초생대 현장적용을 위한 설계 지침서 개발이 요구된다.

• Applied Biological Chemistry
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• 제36권5호
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• pp.381-386
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• 1993

새로운 25종의 Imazethapyr 유도체, (2-(4-isopropyl-4-methyl-5-oxo-2-imidazolin-2-yl)-3-(N-methyl-N-(X)치환-phenylaminooxoacetyl)-5-methylpyridine)들을 합성하여 치환기(X) 변화에 따른 발아 전 후, 피(Echinochla crus-galli.)의 제초활성에 미치는 3-(N-mothy-N-(X)치환-phenylaminoozoacetyl) group의 영향을 검토한 바, 발아 전보다 발아 후의 제초활성에 더 큰 영향을 미침을 알 수 있었다. 발아 후의 제초활성은 X-치환기의 전자밀게 효과와 입체상수 $(E_s)$에 의존적이었으며 가장 큰 제초활성을 나타내는 화합물로는 $bulky(E_s<0)$하고 전자밀게$(\sigma<0)$가 치환된 화합물, 15(4-t-butyl group)와 20(3,5-dimethyl group)이었다. 그리고 높은 제초활성을 나타낼 것으로 예상되는 화합물의 조건들이 검토되었다.

• Applied Biological Chemistry
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• 제50권4호
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• pp.316-320
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• 2007

Chaetomium sp.배양체를 acetone에 침지하여 추출한 후 n-hexane, $CHCl_3$, EtOAc, n-BuOH 및 물로 분획하였다. 이중 EtOAc 분획을 silica gel 및 HPLC(ODS)를 이용하여 3종의 활성물질 A.C-3, A.C-4 및 A.C-5를 분리하였다. 각 화합물의 화학구조를 NMR 및 MS등의 스펙트럼 데이터와 문헌검색을 통하여 chaetoglobosin 유도체인 chaetoglobosin F, chaetoglobosin C 및 chaetoglobosin E로 동정하였다. A.C-3, A.C-4 및 A.C-5의 논피에 대한 유근신장 저해활성 검정 결과, $IC_{50}$값은 각각 66, 65, $67{\mu}g/ml$이었다.

• 농약과학회지
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• 제8권2호
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• pp.145-149
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• 2004

새로운 구조의 2-[4-(6-chloro-2-benzoxazolyloxy)phenoxy]-propionamide 유도체를 합성하여 밭조건하에서 발아후 경엽처리하여 제초 활성을 시험하였다. 합성된 대부분의 화합물은 피에 대해 높은 제초 활성을 나타내었고, 그 중에서 2-[4-(6-chloro-2-benzoxazolyloxy)phenoxy]-N-(2-fluoro-phenyl)-N-methyl propionamide는 벼에 좋은 선택성을 보였다.

• Applied Biological Chemistry
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• 제38권1호
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• pp.90-94
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• 1995

벼(Oryza sativa L.)를 위시하여 논잡초인 피(Echinochloa crus-galli)와 물달개비(Monochoria vaginalis Presl)에 대한 phenylvinylsulfone유도체(S)들의 제초활성을 측정 한 바, 발아 전후에 벼(Oryza sativa L.)이외의 잡초에 대하여 현저하게 속효성이고 선택적인 제초활성을 나타내었다. (S)의 phenyl기에 X-치환기가 변화함에 따른, 구조와 제초활성과의 관계(SAR)를 양자 약리학적 방법으로 분석한 바, 피의 경우에는 ${\pi}$상수가 클수록(${\pi}$<0) 그리고 LUMO가 음의 값으로 증가할수록 제초활성이 증가 하였다. 한편, 물달개비의 경우에는 ${\pi}$상수의 적정값(optimal value)이 1.10이었으므로 이 값에 가까울수록 제초활성이 클 것이며 HOMO에 의존적임을 알 수 있었다. 따라서 X-치환기로 전자끌게가 치환됨으로써 ${\pi}$상수가 크고(${\pi}$<01.10) 음의 값으로 HOMO와 LUMO가 클수록 고활성을 나타낼 수 있는 화합물의 조건들에 대하여 검토되었으며 실험사실을 합리적으로 설명할 수 있는 제초활성 작용기작(mode of action)을 가정 하였다.