• 제목/요약/키워드: lignin biosynthesis

검색결과 27건 처리시간 0.02초

Shear Effects on Production of Lignin Peroxidase by Phanerochaete chrysosporium

  • Sang, Byeong-In;Kim, Yong-Hwan;Yoo, Young-Je
    • Biotechnology and Bioprocess Engineering:BBE
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    • 제1권1호
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    • pp.26-31
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    • 1996
  • Since biosynthesis of lignin peroxidase from Phanerochaete chrysosporium was known to be sensitive to shear, it is interesting to understand the effects of the shear sensitivity for the overproduction of lignin peroxidase. In stirred-tank fermentor, the shear-sensitivity in lignin peroxidase biosynthesis was quantified by using Kolmogorov length scale. It was found that agitation at 80$\mu$m Kolmogorov length scale is advantageous for the production of lignin peroxidase from P. chrysosporium. To overcome the shear sensitivity in lignin peroxidase biosynthesis caused by the agitation,P. chrysosporium was immobilized on various solid carriers. The nylon-immobilized P. chrysosporium was chosen in the present study as a way to overcome the shear sensitivity at the ranges of above 50$\mu$m Kolmogorov length scale. The adhesion force between immobilized cell and carrier can be predicted by thermodynamic approach and used as a criteria to select an adequate carrier materials for immobilization.

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애기장대 MYB7 유전자의 리그닌 생합성 억제 조절 (AtMYB7 Acts as a repressor of lignin biosynthesis in Arabidopsis)

  • 김원찬
    • Journal of Applied Biological Chemistry
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    • 제59권3호
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    • pp.215-220
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    • 2016
  • 식물의 이차생장의 결과로 생산되는 바이오매스의 대부분은 식물의 이차세포벽에 축적된다. 식물의 이차세포벽은 크게 셀룰로스, 헤미셀룰로스, 리그닌이라는 3가지 물질로 구성되며 이들 중 페놀성 복합 화학 물질인 리그닌은 셀룰로스나 헤미셀룰로스와 달리 알코올 발효과정의 저해 물질로이다. 따라서, 식물의 이차세포벽 생합성의 과정을 조절함으로 전체 바이오매스의 생산량과 조성을 바이오 에너지 생산을 위해 최적 조건으로 조절함으로써 바이오 에탄올 생산을 최대화할 수 있을 것이다. 본 연구에서는 애기장대 유래 MYB7 유전자를 CaMV35S 프로모터 조절 하에서 과별현되게 한 식물체와 식물의 전사조절에서 하위 특정 유전자의 발현을 저해시키는 것으로 잘 알려진 SRDX 융합 단백질 즉, MYB7-SRDX 과발현체를 제작하여 그 특성을 조사하였다. 그 결과 MYB7 전사조절 인자가 리그닌의 생합성을 억제 조절한다는 결과를 관찰하였다. 이는 MYB7 전사조절인자를 이용하면 바이오 에탄올 발효과정에 저해 물질로 작용하는 리그닌을 경감시킬 수 있는 기초 자료로 사용할 수 있을 것이다.

종의 포플라수종에서 리그닌생합성에 관계된 OMT유전자의 발현 (Seasonal Expression of OMT Gene in Relation to Lignin biosynthesis in two Poplar Species)

  • 박용구;박희성;최장원;설일환;정일경;신동일
    • 생명과학회지
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    • 제8권4호
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    • pp.443-448
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    • 1998
  • 리그닌함량이 감소한 펄프소재의 육성을 위해 OMT유전자와 리그닌생합성 간의 관계를 2종의 포플라 수종을 이용하여 실험하였다. OMT유전자의 발현은 리그닌생합성이 가장 많이 일어나는 developing secondary xylem에서 높앗다. 이 사부조직에서의 리그닌함량의 증가는 봄에 성장을 개시할 때부터 증가하기 시작하여 8월 말 경에 가장 높았다. 이러한 리그닌의 증가는 OMT유전자의 발현 증가와 일치하였으며, 이는 OMT유전자가 리그닌생합성에서 매우 중요한 역할을 함을 나타내는 것이다.

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Resin Flow, Symptom Development, and Lignin Biosynthesis of Two Pine Species in Response to Wounding and Inoculation with Fusarium circinatum

  • Kim, Ki-Woo;Lee, In-Jung;Kim, Chang-Soo;Eom, In-Yong;Choi, Joon-Weon;Lee, Don-Koo;Park, Eun-Woo
    • The Plant Pathology Journal
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    • 제26권4호
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    • pp.394-401
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    • 2010
  • Resin flow, symptom development, and lignin biosynthesis in response to wounding and fungal inoculation were investigated in Pinus rigida and Pinus densiflora. The two-year-old seedling stems were subjected to three types of treatments: (i) wounding without inoculation, (ii) wound-inoculation with a conidial suspension of Fusarium circinatum, and (iii) pre-wounding woundinoculation with the fungus 20 days after the initial wounding. Resin flow from wounding sites was more evident in P. rigida than P. densiflora in all treatments. The wound-inoculation with the fungus induced almost two-fold higher levels of resin flow than the other treatments in both species. The pre-wounding woundinoculation appeared to result in a decrease in pitch canker development in the two pine species. Some reductions in disease severity were observed in the prewounding wound-inoculated P. rigida, showing a mean disease severity of less than 85%, compared with approximately 100% in the wound-inoculated stems. Disease severity was approximately 50% in the woundinoculated P. densiflora, whereas 10% in the pre-wounding wound-inoculated stems. Higher amounts of lignin were found from bark (ca. 40%) than from xylem (ca. 30%). The wound-inoculated bark and the pre-wounding wound-inoculated bark exhibited higher amounts of lignin among the other treatments. These results suggest that the wound-inoculation apparently prompt the increase in resin flow and lignin biosynthesis from the two pine species, and the prior wounding may be involved in decreased disease severity against the further invasion of F. circinatum.

Roc10, a Rice HD-Zip transcription factor gene, modulates lignin biosynthesis for drought tolerance

  • Bang, Seung Woon;Lee, Dong-Keun;Jung, Harin;Chung, Pil Joong;Kim, Youn Shic;Choi, Yang Do;Suh, Joo-Won;Kim, Ju-Kon
    • 한국작물학회:학술대회논문집
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    • 한국작물학회 2017년도 9th Asian Crop Science Association conference
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    • pp.159-159
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    • 2017
  • Drought, a common environmental constraint, induces a range of physiological, biochemical and molecular changes in plants, and can cause severe reductions in crop yield. Consequently, understanding the molecular mechanisms of drought tolerance is an important step towards crop biotechnology. Here, we report that the rice (Oryza sativa) homeodomain-leucine zipper class IV transcription factor gene, ${\underline{R}ice}$ ${\underline{o}utermost}$ ${\underline{c}ell-specific}$ gene 10 (Roc10), enhances drought tolerance and grain yield by increasing lignin accumulation in ground tissues. Overexpression of Roc10 in rice significantly increased drought tolerance at the vegetative stages of growth and promoted both more effective photosynthesis and a reduction in water loss rate, compared with non-transgenic controls or RNAi transgenic plants. Importantly, Roc10 overexpressing plants had a higher drought tolerance at the reproductive stage of growth and a higher grain yield compared with the controls under field-drought conditions. Roc10 is mainly expressed in outer cell layers including the epidermis and the vasculature of the shoots, which coincides with areas of cell wall lignification. Roc10 overexpression elevated the expression levels of lignin biosynthetic genes in shoots, with a concomitant increase in the accumulation of lignin, while the overexpression and RNAi lines showed opposite patterns of lignin accumulation. We identified downstream target genes of Roc10 by performing RNA-seq and chromatin immunoprecipitation (ChIP)-seq analyses of shoot tissues. Roc10 was found to directly bind to the promoter of PEROXIDASEN/PEROXIDASE38, a key gene in lignin biosynthesis. Together, our findings suggest that Roc10 confers drought stress tolerance by promoting lignin biosynthesis in ground tissues.

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Tension Wood as a Model System to Explore the Carbon Partitioning between Lignin and Cellulose Biosynthesis in Woody Plants

  • Kwon, Mi
    • Journal of Applied Biological Chemistry
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    • 제51권3호
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    • pp.83-87
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    • 2008
  • Tension wood, a specialized tissue developed in the upper side of the leaning stem and drooping branches of angiosperm, is an attractive experimental system attractive for exploring the development and the biochemical pathways of the secondary cell wall formation, as well as the control mechanism of the carbon flux into lignin, cellulose, and hemicellulose. However, the mechanism underlying the induction and the development of the tension wood is largely unknown. Recently, several researchers suggested the possible roles of the plant growth hormones including auxin, gibberellin, and ethylene mainly based on the expression pattern of the genes in this specialized tissue. In addition, expressed sequence tag of Poplar and Eucalyptus provide global view of the genetic control underlying the tension wood formation. However, the roles of the majority of the identified genes have not yet been clearly elucidated. The present review summarized current knowledge on the biosynthesis of tension wood to provide a brief synopsis of the molecular mechanism underlying the development of the tension wood.

Induction and Stabilization of Lignin Peroxidase from Phanerochaete chrysosporium

  • Sang, Byeong-In;Kim, Yong-Hwan;Yoo, Young-Je
    • Journal of Microbiology and Biotechnology
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    • 제5권4호
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    • pp.218-223
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    • 1995
  • Veratryl alcohol which has been reported as an inducer for lignin peroxidase showed different effects on the enzyme biosynthesis in Phanerochaete chrysosporium depending on the addition time. Enzyme expression was optimally induced by adding veratryl alcohol when the carbon source began to be depleted. Hydrogen peroxide, to some extent, stimulated production of lignin peroxidase, but beyond a certain concentration, inactivated lignin peroxidase. Tween 80 induced the formation of small pellets, which were resistant to the deactivation by shear stress. Lignin peroxidase production was increased twice compared with that of the control by adopting all the optimal factors in the culture system.

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리그닌 화학구조 모델의 역사적 고찰 (Historical Consideration of Lignin Models for Native Lignin Structure)

  • 황병호
    • 임산에너지
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    • 제23권1호
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    • pp.45-68
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    • 2004
  • The word of lignin is derived from the Latin word 'ligum' meaning wood. Lignin is complex polymer consisting of coniferyl alcohol, sinapyl alcohol and p-coumaryl alcohol unit and has an amorphous, three dimensional network structure which is hard to be hydrolyzed by acid. Lignin is found in the cell wall of plants lignified. The mode of polymerization of these alcohols in the cell wall lead to a heterogeneous branched and cross-linked polymer in which phenyl propane units are linked by carbon-carbon and carbon-oxygen bonds. This polymerization of precursors, p-coumaryl alcohol, coniferyl alcohol and sinapyl alcohol to lignin is formed by enzymic dehydrolyzation. The reaction is initiated by an electron transfer which results in the formation of resonance-stabilized phenoxy radical. The combination of these radicals produces a variety of dimers, trimers and oligomers and so on. Lignin research has been divided into basic and practical application field. The basic studies contains biosynthesis, chemical structure, distribution in the cell wall and reactivity by reductants, oxidants and organic solvents. The application research will be approached the reaction of lignin in various pulp making involving pulp bleaching and its effect on pulp qualities. Lignin also will be studied for the production of fine chemicals, polymer products and the conservation into an energy source like petroleum oil because the amount of lignin produced in pulp making process is more than 51,000,000 tons per year in the world. Both basic and application research must lay emphasis on the development for the utilization of lignin and the pulping process. But these researches can not be completed without understanding lignin structure containing functional groups. Therefore, this paper was focused on the review of lignin formulation which has been studied since 1948 in chronological order. This review was based on monomers, dimers, trimers and tetramers of phenyl propane unit structures which were isolated and identified by different methods from various wood.ious wood.

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