• Title/Summary/Keyword: protoporphyrinogen oxidase

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Purification and Characterization of Bacillus subtilis Protoporphyrinogen Oxidase and Pre-equilibrium Behavior During Oxidation of Protoporphyrinogen IX

  • Jeong, Eun-Ju;Han, Ok-Soo
    • BMB Reports
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    • v.34 no.1
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    • pp.39-42
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    • 2001
  • Previous studies indicate that B. subtilis protoporphyrinogen oxidase is poorly inhibited by diphenyl ether herbicides. To better understand the basis of this insensitivity, the enzyme was overexpressed as a soluble protein in E. coli, purified and characterized. The mechanism of oxidation of B. subtilis protoporphyrinogen IX was studied and the enzyme kinetic parameters were determined for protoporpyrinogen IX; $K_m$, and $k_{cat}$ were $6.3\;{\mu}M$ and $0.028\;h-^1$, respectively. The enzyme required flavin adenine dinucleotide as a cofactor and its activity was enhanced by 1 mM n-octylglucopyranoside. The nonenzymatic oxidation rate was dependent on the concentration of protoporphyrinogen IX, suggesting that the reaction involves a pre-equilibrium step followed by a rate-limiting step.

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Physiology and Growth of Transgenic Tobacco Plants Containing Bacillus subtilis Protoporphyrinogen Oxidase Gene in Response to Oxyfluorfen Treatment (Bacillus subtilis Protoporphyrinogen Oxidase 유전자 형질전환 담배의 Oxyfluorfen 처리에 대한 생리 · 생장반응)

  • Lee, J.J.;Kuk, Y.I.;Chung, J.S.;Lee, S.B.;Choi, K.W.;Han, O.S.;Guh, J.O.
    • Korean Journal of Weed Science
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    • v.18 no.3
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    • pp.237-245
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    • 1998
  • The transgenic tobacco (Nicotiana tabacum cv. Xanthi) plants containing Bacillus subtilis protoporphyrinogen oxidase gene with cauliflower mosaic virus 35S promoter have recently been generated by using Agrobacterium-mediated gene transformation. The nontransgenic and the transgenic tobacco plants were compared with respect to responses to diphenyl ether herbicide oxyfluorfen and under various environmental conditions. Both cellular leakage and lipid peroxidation caused by oxyfluorfen were found to be less in the transgenic than in the nontransgenic plants. Growth responses of the transgenic plants under various temperature, light, and water conditions were almost the same as those of the nontransgenic plants, although the transgenic plants exhibited slightly more retarded growth under low light or saturated water condition. These results revealed that the transgenic tobacco plants containing B. subtilis protoporphyrinogen oxidase gene under cauliflower mosaic virus 35S promoter were relatively resistant to oxyfluorfen and exhibited normal growth pattern. Possible mechanism of resistance to oxyfluorfen in the transgenic plants is also discussed.

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Expression Site of Protoporphyrinogen Oxidase Influences on Herbicide Resistance in Transgenic Rice (형질전환 벼에서 Protoporphyrinogen Oxidase의 발현 위치가 제초제 저항성에 미치는 영향)

  • Jung, Sun-Yo
    • Korean Journal of Weed Science
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    • v.30 no.3
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    • pp.225-232
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    • 2010
  • The effect of Protox expression site on herbicidal resistance was investigated in wild-type and transgenic rice plants imposed by peroxidizing herbicide oxyfluorfen. The transgenic rice systems involved the plastidal expression of Arabidopsis protoporphyrinogen oxidase (Protox; AP line) and the dual expression of Myxococcus xanthus Protox in chloroplasts and mitochondria (TTS line). The oxyfluorfen-treated TTS4 line showed the lower levels of cellular leakage and malonyldialdehyde and the sustained capacity of 5-aminolevulinic acid synthesis, compared to the oxyfluorfen-treated AP and wild-type lines. During oxyfluorfen action, the TTS4 line had greater herbicide resistance than the AP1 line, indicating that the dual expression of M. xanthus Protox in chloroplasts and mitochondria prevented the accumulation of photodynamic protoporphyrin IX more effectively than the expression of Arabidopsis Protox only in chloroplasts. These results suggest that the ectopic expression of Protox in mitochondria greatly contributes to the herbicidal resistance in rice plants.

Synthesis and Herbicidal Activities of Hydantoin Derivatives Possessing Amide Subgroup (아미드 치환체를 갖는 히단토인계 화합물의 합성과 제초활성 연구)

  • Ko, Young-Kwan;Chung, Keun-Hoe;Ryu, Jae-Wook;Woo, Jae-Chun;Koo, Dong-Wan;Choi, Jung-Sub;Kim, Jun-Young;Kim, Tae-Joon;Kwon, Oh-Yeon;Chung, Bong-Jin;Kim, Dae-Whang
    • The Korean Journal of Pesticide Science
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    • v.10 no.2
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    • pp.153-156
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    • 2006
  • As an ongoing research program for the development of environmentally friendly new herbicide, several hydantoin derivatives 5a - 5i possessing amide subgroup were synthesized and shown to have interesting herbicidal activities exhibiting symptoms as Protoporphyrinogen IX oxidase inhibitor under postemergence upland greenhouse screening. Among derivatives tested, compound 5h showed superior herbicidal activity against upland problem weed, digitaria sanguinalis and aeschynomene indica to reference compound fluthiacet-methyl.

Synthesis and Herbicidal Activities of Tetrahydroindazole Derivatives Possessing Hydroxyalkyl Subgroup (하이드록시알킬 치환체를 갖는 테트라하이드로인다졸계 화합물의 합성과 제초활성 연구)

  • Ko, Young-Kwan;Chung, Kun-Hoe;Ryu, Jae-Wook;Woo, Jae-Chun;Koo, Dong-Wan;Choi, Jung-Sup;Kim, Jun-Young;Kim, Su-Ho;Kim, Tae-Joon;Choi, In-Young;Seok, Mee-Young;Choi, Jun-Hyuk;Chung, Bong-Jin
    • The Korean Journal of Pesticide Science
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    • v.12 no.2
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    • pp.201-205
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    • 2008
  • As an ongoing research program for the development of environmental friendly new soil-surface treatment herbicide, several tetrahydroindazole derivatives 6a - 6h possessing hydroxyalkyl subgroup were synthesized and shown to have interesting herbicidal activities exhibiting sumptoms as protoporphyrinogen IX oxidase inhibitor under pre-emergence upland greenhouse screening. Among derivatives tested, compound 6f showed superior herbicidal activity against problem weeds.

Different Physiological Activity of Selected Rice Cultivars to Diphenylether Herbicide, Oxyfluorfen - III. Differential Protoporphyrinogen Oxidase(Protox) Activity and Protoporphyrinogen IX(PPIX) Accumulation (Oxyfluorfen에 대한 내성(耐性) 및 감수성(感受性) 벼품종(品種)의 생리활성(生理活性) 기구 (機構) - III. Protoporphyrinogen oxidase(Protox)활성(活性)과 Protoporphyrinogen IX(PPIX) 축적(蓄積))

  • Kuk, Y.I.;Guh, J.O.;Chun, J.C.
    • Korean Journal of Weed Science
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    • v.16 no.2
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    • pp.150-159
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    • 1996
  • This study was conducted to investigate the inhibition of protox activity and the PPIX accumulation of the oxyfluorfen-tolerant and-susceptible rice cultivars with barnyardgrass, a typical susceptible weed in accordance by oxyfluorfen treatment. The susceptible rice cultivars and barnyardgrass showed more inhibition of protox activity due to the treatment of oxyfluorfen than the tolerant rice cultivars. Especially in the concentration at $10^{-6}$M treatment, protox activity of the susceptible rice cultivars and barnyardgrass were the completely inhibited but the tolerant rice cultivars kept 32~59% of activity compared to the control. As the treatment concentration increased, the content of PPIX accumulation increased and it increased untill four hours of light exposure but it tended to decrease these after. The content of PPIX accumulation by the treatment of oxyfluorfen was more pronounced in the light condition than in the dark. Under the light and dark conditions, the susceptible rice cultivars and barnyardgrass showed more PPIX accumulation than the tolerant rice cultivate. Especialiy the susceptible barnyardgrass had more than the rice. With the treatment of GC and DA, tetrapyrrole biosynthesis inhibitor, the herbicidal activity by oxyfluorfen was inhibited, and the susceptible rice cultivars and barnyardgrass tended to have less effective than the tolerant rice cultivars and the content of chlorophyll or PPS accumulation tended to be similar.

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Mechanism of Protoporphyrinogen Oxidase-inhibiting Herbicide, Oxyfluorfen Tolerance in Squash leaves of Various Ages (Protoporphyrinogen Oxidase 저해형 제초제 Oxyfluorfen에 대한 호박 엽령별 내성기작)

  • Kuk, Yong-In;Yun, Young-Beom
    • Korean Journal of Weed Science
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    • v.30 no.2
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    • pp.111-121
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    • 2010
  • Differential tolerance to protoporphyrinogen oxidase (Protox)-inhibiting herbicides, oxyfluorfen was observed between leaf ages in squash. Physiological responses to oxyfluorfen, including leaf injury, cellular leakage, accumulation of tetrapyrroles, and antioxidative enzymes activity, were investigated in leaf age classes of squash to identify mechanisms of oxyfluorfen tolerance. Leaf 1, 2, and 3 injuries for Joongangaehobak were >10,000, 1,286, and 1.6-fold higher than that of leaf 4, after treatment of oxyfluorfen. On the other hand, leaf 1, 2, and 3 injuries for Sintowjahobak were 725, 366, and >0.6-fold higher than that of leaf 4, after treatment of oxyfluorfen. However, in contrast to oxyfluorfen treatment results, leaf injury of squash leaf 4 treated with paraquat was much smaller than in leaves 1, 2 and 3. Electrolyte leakage from the tissues treated with oxyfluorfen was higher in the youngest leaf (Leaf 4) than in the older leaves 1, 2, and 3. Differential leaf response to oxyfluorfen of squash appears to be due in large part to differences in protoporphyrin IX (Proto IX), Mg-Proto IX, and Mg-Proto IX monomethyl ester accumulation in treated leaves. In contrast, leaf 4 had higher activities of superoxide dismutase, catalase, peroxidase, ascorbate peroxidase, and glutathione reductase than leaf 1 after treatment with oxyfluorfen. However, the induction in antioxidant activity in leaf 4 was not enough to overcome the toxic effects of a Protox inhibitor, oxyfluorfen, so the leaf eventually died.

Growth and Yield Response of Transgenic Rice Plants Expressing Protoporphyrinogen Oxidase Gene from Bacillus subtilis

  • Kuk, Yong-In;Chung, Jung-Sung;Sunyo Jung;Kyoungwhan Back;Kim, Han-Yong;Guh, Ja-Ock
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.48 no.4
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    • pp.326-333
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    • 2003
  • Transgenic rice plants expressing a Bacillus subtilis protoporphyrinogen oxidase (Protox), the last shared enzyme of the porphyrin pathway in the expressed cytoplasm or the plastids, were compared with non-trangenic rice plants in their growth characteristics such as tiller number, plant height, biomass, and yield. Transgenic rice plants of $\textrm{T}_3$ generation had 8 to 15 % and 25 to 43% increases in tiller number compared to non-transgenic rice plants at 4 and 8 weeks after transplanting(WAT); similar values were observed for $\textrm{T}_4$ generation at 4 and 8 WAT. However, the plant height in both $\textrm{T}_3$ and $\textrm{T}_4$ generations was similar between transgenic rice plants and non-transgenic rice plants at 4 and 8 WAT. Transgenic rice plants had 13 to 32% increase in above-ground biomass and 9 to 28% increase in grain yield compared to non-transgenic rice plants, demonstrating that biomass and yield correlate with each other. The increased grain yield of the transgenic rice plants was closely associated with the increased panicle number per plant. The percent of filled grain, thousand grains and spikelet number per panicle were similar between transgenic and non-transgenic rice plants. Generally, the growth and yield of transgenic generations ($\textrm{T}_2$, $\textrm{T}_3$, and $\textrm{T}_4$) and gene expressing sites (cytoplasm-expressed and plastid-targeted transgenic rice plants) were similar, although they slightly varied with generations as well as with gene expressing sites. The transgenic rice plants had promotive effects, indicating that regulation of the porphyrin pathway by expression of B. subtilis Protox in rice influences plant growth and yield.

Fitness cost and competitive ability of transgenic herbicide-tolerant rice expressing a protoporphyrinogen oxidase gene

  • Chun, Young Jin;Kim, Dae In;Park, Kee Woong;Jeong, Soon-Chun;Park, Sangkyu;Back, Kyoungwhan;Kim, Chang-Gi
    • Journal of Ecology and Environment
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    • v.36 no.1
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    • pp.39-47
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    • 2013
  • The expression of transgenic traits in genetically modified crops is sometimes associated with decreases in crop performance or fitness. These decreases in performance or fitness of transgenic plants in unfavourable conditions may provide valuable information about the ecological consequences of transgene escape. In a glasshouse trial, we tested the cost associated with resistance to herbicides by comparing the growth, yield, and competitive ability of transgenic rice with its parental non-transgenic line. This new line was developed for constitutive overexpression of protoporphyrinogen oxidase (PPO) to increase resistance to herbicides. We evaluated nine agronomic traits of transgenic and non-transgenic rice grown in a replacement series design over four densities. Competitive ability was also assessed between transgenic and non-transgenic plants by analyzing their relative yields based on biomass and seed weight data. Our results indicated that non-transgenic plants showed greater performance than did the transgenic plants when those genotypes were grown in mixtures. The non-transgenic rice plants exhibited superior competitive ability at certain combinations of planting densities and genotype proportions. These results suggest that PPO-herbicide resistance incurs some costs in plant performance and competitive ability.