• Journal of Applied Biological Chemistry
• /
• 제48권4호
• /
• pp.187-192
• /
• 2005

Influence of herbicide oxadiazon on soil microbial activity and nitrogen dynamics was evaluated. Soil samples were treated with oxadiazon at field and tenfold field rates and incubated. Organic amendment was added as an additional substrate for soil microorganisms. Tenfold field rate oxadiazon stimulated substrate-induced respiration (SIR) and dehydrogenase activity (DHA) in amended soil as compared to unamended soil and control treatment. Soil urease activity was not affected by oxadiazon treatment. In both amended and unamended soils, treatment of the herbicide at higher rate had not significant influence on $NH_4$-N and $NO_3$-N concentrations. Higher dose of oxadiazon was degraded in both soils, but dissipation rate in amended soil was higher than unamended soil, with half-lives ($t_{1/2}$) of 23.1 and 138.6 days, respectively. Recommended field rate did not affect microbial activity and nitrogen dynamics in soil ecosystem. Results showed influence of oxadiazon on cycling processes of nitrogen in soil was not significant however its effect on microbial activity was a tendency depending on addition of organic amendment to soil.

• 한국잡초학회지
• /
• 제16권1호
• /
• pp.28-35
• /
• 1996

갈대방제용 선택성 제초제를 스크리닝하기 위한 대조약제로서의 tetrapion의 특성을 온실 및 포장실험을 통하여 조사하였다. 1. Tetrapion을 처리한 식물은 잎이 휘면서 황화되고 생장이 억제되는 증상을 나타내었는데 처리농도가 높을 때에는 식물체 전체가 고사되었다. 2. Tetrapion은 목화를 제외한 모든 작물에 심한 약해를 일으켰으며 벼에 대해서는 직파 벼나 이앙벼의 경우 모두 약해를 일으켰다. 3. Tetrapion의 효과는 광엽 잡초보다 화본과 잡초에 대해 크게 나타났다. 4. Tetrapion은 경엽처리시보다 토양처리시에 더 우수한 효과를 나타내었다. 5. 포장실험시 tetrapion의 갈대방제효과는 처리시기와 포장의 토성에 따라 큰 차이가 있었으며 40kg/ha 이상의 고농도로 tetrapion을 처리하였을 경우에 갈대가 효과적으로 방제되었다. 이러한 결과는 억새의 경우에서도 유사한 경향이었다. 6. Tetrapion은 온실에서 키운 갈대에 대해 토양 및 경엽처리시 모두 우수한 방제효과를 나타내어 갈대방제용 제초제의 스크리닝에 사용할 수 있는 대조약제로서의 가치가 있었다.

• 한국잡초학회지
• /
• 제15권4호
• /
• pp.247-253
• /
• 1995

The herbicide butachlor [N-(butoxymethyl)-2-chloro-N-(2,6-di-methylphenyl) acetamide] is widely used by farmers as a tool for weed management of transplanted rice(Oryza sativa L.) in Taiwan. The herbicide did not stop germination of rice and weed seeds, but strongly inhibited the subsequent growth of young shoots and roots. The inhibition was also strong on established seedlings. However, they could recover to normal growth after the herbicide effect disappeared. Butachlor greatly decreased the endogenous indole-3-acetic acid (IAA) but increased the endogenous abscisic acid (ABA) contents of rice seedlings. Addition of lAA into growth medium (Hoagland's solution) partly relieved growth inhibition. Pretreatment of both gibberellic acid ($GA_3$) and IAA 24 hours before butachlor treatment almost completely alleviated the butachlor-interfere with GA and/or IAA metabolism or their action resulting in the growth inhibition of rice. Butachlor was readily absorbed by rice roots. During 24 hours of uptake experiment, 32% of the applied herbicide was absorbed. Pretreatment of the herbicide for 2 days did ncx affect the absorption. Of the absorbed herbicide, 80% remained in roots, only 20% transported into shoots, and more than 50% was metabolized to water soluble substances. Thin-layer chromatographic (TLC) analysis indicated that the Rf value of the most abundant metabolite was butachlor-glutathione conjugate. Rice, barnyardgrass (Echinochloa crus-galli (L.) Beauv.), and monochoria (Monochoria vaginalis Presl) seedlings contained relatively high level of non-protein thiols, while the glutathione S-transferase (GST) activity was found highest in rice, barnyardgrass the next, monochoria the lowest. The difference in GST activity among these species might be related to their sensitivity to butachlor.

• 한국작물학회지
• /
• 제23권3호
• /
• pp.31-46
• /
• 1978

In order to secure the proper use of herbicides that are frequently used in Korea, the behavior of herbicides in various type of soil were studied. This study includes the variation of phytotoxicity, leaching and movement, and residual activity period of herbicides depending upon the type of soil etc. Experiments were also conducted to establish a guideline for the selection of herbicides according to the type of soil and the proper use of each herbicide in various type of soil in Korea. Experimental results showed that the behavior of herbicides could be characterized based on the series or kind of herbicides and devided into two major groups. One group (nitrofen. CNP, benthiocarb and butachlor) of herbicides showed relatively little crop injury and was very dependable. The action of this group was not remarkably influenced by soil components, rainfall and the quantity of herbicide used with the type of soil that had small adsorption capacity such as most of soil in Korea. The other group(simazine, 2, 4-D. linuron, alachlor and simetryne) showed a wide variation in it's action and retained potentially injurious effect. This group was very susceptable to using condition as well as the type of soil itself. Based on the results of various experiments the disappearance of the residual activity period of major herbicides used in upland and paddy field and the related factors were explained. It is believed that the results of this study can be used as a base for the establishment of a guideline for the proper use of each herbicide and can suggest a direction of developing new herbicides.

• Environmental Engineering Research
• /
• 제12권4호
• /
• pp.136-147
• /
• 2007

In an effort to identify possible microbes for seeking bioagents for remediation of herbicide-contaminated soils, seven species of phototrophic nonsulfur bacteria (Rhodobacter capsulatus and sphaeroides, Rhodospirillum rubrum, Rhodopseudomonas acidophila, blastica and viridis, Rhodomicrobium vannielii) were grown in the presence of the herbicide, butachlor, and bacterial growth rates and nitrogen fixation were measured with different carbon sources. Under general conditions, all species showed 17-53% reductions in growth rate following butachlor treatment. Under nitrogen-fixing conditions, Rb. capsulatus and Rs. rubrum showed 1-4% increases in the growth rates and 2-10% increases in nitrogen-fixing abilities, while the other 5 species showed decreases of 17-47% and 17-85%, respectively. The finding that Rp. acidophila, Rp. blastica, Rp. viridis and Rm. vannielii showed stronger inhibitions of nitrogenase activity seems to indicate that species in genera Rhodobacter and Rhodospirillum are less influenced by butachlor than those in Rhodopseudomonas and Rhodomicrobium in terms of nitrogen-fixing ability. Overall, nitrogenase activity was closely correlated with both growth rate and glutamine synthetase activity (representing nitrogen metabolism). When the carbon sources were compared, pyruvate (three carbons) was best for all species in terms of growth rate and nitrogen fixation, with malate (four carbons) showing intermediate values and ribose(five carbons) showing the lowest; these trends did not change in response to butachlor treatment. We verified that each of the 7 species had a plasmid ($12.2{\sim}23.5\;Kb$). We found that all 7 species could use butachlor as a sole carbon source and 3 species were controlled by plasmid-born genes, but it is doubtful whether plasmid-born genes were responsible to nitrogen fixation.

• Biomolecules & Therapeutics
• /
• 제10권4호
• /
• pp.224-229
• /
• 2002

Triazine herbicide has been reported to directly suppress the immune response. In the present study, we examined various functions of murine peritoneal macrophages that were isolated and stimulated with LPS after simazine (300 and 600 mg/kg body weight), a triazine herbicide, was administered every day for 4 weeks. Simazine decreased the capacity of phagocytosis, compared to those of carboxymethylcellulose (CMC)-treated control group. In addition, the production of NO and TNF-$\alpha$ was decrcased in macrophages of simazinetreated mice. However, the production of hydrogen peroxide ($H_{2}O_{2}$) was not altered. In vitro tumoricidal activity of in vivo simazine-treated macrophages was reduced against target cell. B 16 melanoma. Taken together, these results suggested that simazine might have the immunosuppressive effect on macrophages after in vivo exposure, which was related to the reduction of tumoricidal activity.

• 미생물학회지
• /
• 제14권3호
• /
• pp.128-128
• /
• 1976

19 pesticides including 12 insecticides, 2 herbicides and 5 fungicides have been tested for mutagenic activity in the Salmonella/microsome system. It was found that insecticides, DDVP, Trichlorfon, Sumithion, Naled, fungicide, TMTD and herbicide NIP induced base substitute mutation and herbicide MO frameshift mutation. Mutagenicity of Sumithion and NIP was appeared only after rat microsomal enzyme activation and that of TMTD was increased after the microsomal enzyme activation.

• 미생물학회지
• /
• 제14권3호
• /
• pp.123-134
• /
• 1976

19 pesticides including 12 insecticides, 2 herbicides and 5 fungicides have been tested for mutagenic activity in the Salmonella/microsome system. It was found that insecticides, DDVP, Trichlorfon, Sumithion, Naled, fungicide, TMTD and herbicide NIP induced base substitute mutation and herbicide MO frameshift mutation. Mutagenicity of Sumithion and NIP was appeared only after rat microsomal enzyme activation and that of TMTD was increased after the microsomal enzyme activation.

• Applied Biological Chemistry
• /
• 제43권1호
• /
• pp.52-56
• /
• 2000

Fenoxaprop-ethyl계 화합물의 amide 형태인 일련의 2-(4-(6-chloro-2-benzoxazolyloxy)phenoxy)-N-Phenylpropionamide 유도체 중 N-phenyl 고리상 X-치환체들이 변화함에 따른 구조와 수답에서 발아 전(pre)과 후(post), 벼(Oryza sativa L.)에 미치는 약해와의 관계(SAR)를 Free-Wilson 방법과 Hansch방법을 이용하여 정량적으로 검토하였다. 대체적으로 발아 전, 벼에 대한 약해는 N-phenyl 고리상 para-치환된 1 치환체들과 2,3,4-치환된 3 치환체로서 소수성의 적정값, $({\pi})_{opt}=0.91$을 가지는 전자밀게가 영향을 미친 반면에 발아 후에는 meta치환된 1 치환체들과 2,3-치환된 2 치환체로서 적정값(({\pi})_{opt}=0.5)$의 소수성을 갖는 fluoro, acetyl 및 carboxyl등, 주로 전자 끌게 들이 비교적 영향을 미쳤다. 그리고 기질물질은 발아 전 보다 발아 후의 벼에 대하여 더 큰 약해를 미치고 있슴을 알았다. SAR식에 따라 온실내에서 가장 약해를 별 나타내는 화합물은 2-methyl-3-methoxy-4-cyano치환체로 예상되었다. 그리고 가수분해 반응의 유형은 친핵성 첨가제거 $(Ad_{Nu-E})$ 반응에 따른 궤도조절 반응으로 진행되었으며 비(H) 치환체에 대한 분자 정전기 전위(MEP)에 대하여 검토하였다.

• 한국잡초학회지
• /
• 제9권3호
• /
• pp.230-237
• /
• 1989

Bleaching herbicides(oxyfluorfen, oxadiazon, paraquat)의 작용발현에 영향을 미치는 온도 및 광의 효과를 조사한 결과 oxyfluorfen 과 oxadiazon의 제초활성은 $10-35^{\circ}C$에서 온도가 증가될수록 높았으며 온도의 효과는 제초작용 발현단계(photooxidation) 보다는 그 이전 단계에서 더욱 큰 영향이었다. 처리약제 모두 광도가 높을수록 활성이 강하였으며 paraquat 는 광질간의 활성차이가 없었으나 oxyfluorfen 및 oxadiazon 은 챙색광에서 높은 활성을 보였고 이들 두 약제에 대한 광의 효과는 광합성 및 호흡의 전자전달계나 carotenoid 생합성 보다는 chlorophyll 생합성 과정과 일정한 관련이 있다.