• 제목/요약/키워드: Radiation-induced Degradation

검색결과 52건 처리시간 0.025초

The Role of Heat Shock Protein 25 in Radiation Resistance

  • Lee Yoon-Jin;Lee Su-Jae;Bae Sangwoo;Lee Yun-Sil
    • 한국환경성돌연변이발암원학회지
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    • 제25권2호
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    • pp.51-59
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    • 2005
  • Overexpression of HSP25 delayed cell growth, increased the level of $p21^{waf}$, reduced the levels of cyclin D1, cylcin A and cdc2, and induced radioresistance in L929 cells. We demonstrated that extracellular regulated kinase (ERK) and MAP kinase/ERK kinase (MEK) expressions as well as their activation (phospho-forms) were inhibited by hsp25 overexpression. To confirm the relationship between ERK1/2 and hsp25-mediated radioresistance, ERK1 or ERK2 cDNA was transiently transfected into the hsp25 overexpressed cells and their radioresistance was examined. HSP25-mediated radioresistance was abolished by overexpression of ERK2, but not by overexpression of ERK1. Alteration of cell cycle distribution and cell cycle related protein expressions (cyclin D, cyclin A and cdc2) by hsp25 overexpression were also recovered by ERK2 cDNA transfection. Increase in Bc1-2 protein by hsp25 gene transfection was also reduced by subsequent ERK2 cDNA-transfection. In addition, HSP25 overexpression reduced reactive oxygen species (ROS) and increased expression of manganese superoxide dismutase (MnSOD) gene. Increased activation of NF-kB (IkB degradation) was also found in hsp25-overexpressed cells. Moreover, transfection of hsp25 antisense gene abrogated all the HSP25-mediated phenomena. To further elucidate the exact relationship between MnSOD induction and NF-kB activation, dominant negative $I-kB\alpha(I-kB\alpha-DN)$ construction was transfected to HSP25 overexpressed cells. $I-kB\alpha-DN$ inhibited HSP25 mediated MnSOD gene expression. In addition, HSP25 mediated radioresistance was blocked by $I-kB\alpha-DN$ transfection. Blockage of MnSOD with antisense oligonucleotides in HSP25 overexpressed cells, prevented apoptosis and returned the ERK1/2 activation to the control level. From the above results, we suggest for the first time that reduced oxidative damage by HSP25 was due to MnSOD-mediated down regulation of ERK1/2.

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방사선조사를 받은 흰쥐 소장 점막의 손상과 재생과정 중 금속단백효소 및 억제자의 발현 (Expression of Matrix Metalloproteinase-2 and Tissue Inhibitor of Metalloproteinase-2 in Radiation Exposed Small Intestinal Mucosa of the Rat)

  • 곽현주;이경자;이정식
    • Radiation Oncology Journal
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    • 제21권1호
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    • pp.66-74
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    • 2003
  • 목적 : 금속단백효소(MMPs)는 세포외 기질의 분해가 주 기능이며 금속단백효소와 억제자(TIMPS)가 상처 치유 과정과 자외선 조사에 의한 피부노화에 관여한다는 것이 알려져 있다. 그러나 방사선조사 후 금속단백효소와 억제자의 발현에 관한 연구는 보고된 바 없다. 본 연구는 흰쥐의 소장에 방사선을 조사하여 금속단백효소와 억제자의 발현을 시간적으로 관찰하여 방사선에 의한 소장 점막 손상 및 재생과정과 금속단백효소와 억제자의 관계를 밝히고자하였다. 대상 및 방법 : 실험동물로 암, 수 구별 없이 생후 4~5개월, 체중 250~300 gm의 흰쥐(Spraque-Dawley) 30마리를 대상으로 하여 실험군으로 전복부에 8 Gy의 방사선을 조사한 후 1일, 2일, 3일, 5일, 7일, 14일에 각각 5마리씩 희생시켜 소장을 적출하여 사용하였고, 정상대조군은 각 시기별로 1마리씩 사용하였다. H&E 염색을 하여 조직병리검사를 하였고, MMP와 TIMP끌의 발현에 대해서는 면역조직화학염색, 면역블로팅, ELISA법으로 확인하였다. 결과 : 조직병리 소견상 방사선조사에 의한 소장 조직손상은 1일부터 관찰되어 2일과 3일에 현저하였고 재생은 3일에 관찰되어 5일에 현저하였다 면역조직화학염색 결과 MMP는 1일에 발현되어 3일, 5일에 가장 강하게 나타났으며 TIMP를는 1일에 나타나기 시작하여 5일에 가장 강하게 나타났다. 면역블로팅 결과 MMP◎는 3일과 5일에강하게 나타났으며 TIMP끌는 1, 3, 5, 7일에 같은 정도의 양성반응을 보였다. 혈액에서의 MMP와 TIMP의 ELISA 검사법에서는 대조군에 비해 방사선조사군에서 통계적으로 유의한 증가가 있었고 방사선조사 후 1, 2, 3, 5, 7, 14일 각각에서 유의한 차이가 있었으며 5일에 가장 높은 수치를 보였다. 결론 : 방사선조사 후 조직병리학적 검사에서 손상의 척도인 염증 반응과 재생의 척도인 유사분열 수의 변화가 면역조직화학염색, 면역블로팅, ELISA검사에 의한 MMP-2, TIMP의 증가와 일치하는 것으로 나타나 이들이 방사선 조사 후 조직 손상과 재생 기전에 역할을 하고 있음을 보여주었다.

Molecular Analysis of the Salmonella Typhimurium tdc Operon Regulation

  • Kim, Min-Jeong;Lim, Sang-Yong;Ryu, Sang-Ryeol
    • Journal of Microbiology and Biotechnology
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    • 제18권6호
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    • pp.1024-1032
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    • 2008
  • Efficient expression of the Salmonella Typhimurium tdc ABCDEG operon involved in the degradation of L-serine and L-threonine requires TdcA, the transcriptional activator of the tdc operon. We found that the tdcA gene was transiently activated when the bacterial growth condition was changed from aerobic to anaerobic, but this was not observed if Salmonella was grown anaerobically from the beginning of the culture. Expression kinetics of six tdc genes after anaerobic shock demonstrated by a real-time PCR assay showed that the tdc CDEG genes were not induced in the tdcA mutant but tdcB maintained its inducibility by anaerobic shock even in the absence of tdcA, suggesting that an additional unknown transcriptional regulation may be working for the tdcB expression. We also investigated the effects of nucleoid-associated proteins by primer extension analysis and found that H-NS repressed tdcA under anaerobic shock conditions, and fis mutation delayed the peak expression time of the tdc operon. DNA microarray analysis of genes regulated by TdcA revealed that the genes involved in N-acetylmannosamine, maltose, and propanediol utilization were significantly induced in a tdcA mutant. These findings suggest that Tdc enzymes may playa pivotal role in energy metabolism under a sudden change of oxygen tension.

Agastache rugosa Kuntze Attenuates UVB-Induced Photoaging in Hairless Mice through the Regulation of MAPK/AP-1 and TGF-β/Smad Pathways

  • Yun, Mann-Seok;Kim, Changhee;Hwang, Jae-Kwan
    • Journal of Microbiology and Biotechnology
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    • 제29권9호
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    • pp.1349-1360
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    • 2019
  • Chronic exposure to ultraviolet (UV) radiation, regarded as a major cause of extrinsic aging or photoaging characterized by wrinkle formation and skin dehydration, exerts adverse effects on skin by causing the overproduction of reactive oxygen species. Agastache rugosa Kuntze, known as Korean mint, possesses a wide spectrum of biological properties including anti-oxidation, anti-inflammation, and anti-atherosclerosis. Previous studies have reported that A. rugosa protected human keratinocytes against UVB irradiation by restoring the anti-oxidant defense system. However, the anti-photoaging effect of A. rugosa extract (ARE) in animal models has not yet been evaluated. ARE was orally administered to hairless mice at doses of 100 or 250 mg/kg/day along with UVB exposure for 12 weeks. ARE histologically improved UVB-induced wrinkle formation, epidermal thickening, erythema, and hyperpigmentation. In addition, ARE recovered skin moisture by improving skin hydration and transepidermal water loss (TEWL). Along with this, ARE increased hyaluronic acid levels by upregulating HA synthase genes. ARE markedly increased the density of collagen and the amounts of hydroxypoline via two pathways. First, ARE significantly downregulated the mRNA expression of matrix metalloproteinases responsible for collagen degradation by inactivating the mitogen-activated protein kinase/activator protein 1 pathway. Second, ARE stimulated the transforming growth factor beta/Smad signaling, consequently raising the mRNA levels of collagen-related genes. In addition, ARE not only increased the mRNA expression of anti-oxidant enzymes but also decreased inflammatory cytokines by blocking the protein expression of nuclear factor kappa B. Collectively, our findings suggest that A. rugosa may be a potential preventive and therapeutic agent for photoaging.

SKH-1 Hairless Mice에서의 히알루론산 경구 투여를 통한 피부 광노화 개선 효과 (Anti Photoaging Effects of Hyaluronic Acid following Oral Administration in SKH-1 Hairless Mice)

  • 이성진;서윤희;윤민규;유희종;최수영
    • 한국식품영양학회지
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    • 제28권6호
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    • pp.941-946
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    • 2015
  • 본 연구에서는 HA에 대하여 UVB로 주름을 유도시킨 hairless mice에게 경구 투여를 하였을 때, 주름 개선에 미치는 영향을 관찰하였다. 쥐는 UV를 쪼여 광노화를 진행하였으며, HA는 UVB에 노출시키기 4주 전부터 투여하여 총 14주 동안 투여하였다. 주름 개선 평가는 replica 제작하여 주름의 길이, 깊이, 개수, 두께로 평가하였다. 또한, 피부의 조직학적 평가를 통해 진피층 내 교원섬유와 탄력섬유의 양과 형태를 관찰하였다. 10주 동안의 HA를 급여하였을 때 주름의 깊이, 두께, 개수를 측정한 주름 개선 평가에서 세 항목 모두 개선되는 결과를 보였다. 특히 HA의 160 mg/kg 농도에서는 주름의 깊이는 $19.44{\pm}0.75{\mu}m$, 주름 수는 $654.00{\pm}98.34$, 주름두께는 $1.35{\pm}0.08mm$로 양성 대조군(RA)의 결과(주름깊이; $19.28{\pm}0.95{\mu}m$, 주름 수; $953.57{\pm}83.54$, 주름두께; $1.34{\pm}0.07mm$)와 비슷한 수치를 나타내며, 우수한 피부 광노화 개선효과를 보였다. 하지만, 주름길이의 결과에서는 유의적 차이를 나타내지 않았다. HA의 섭취로 인한 교원섬유 및 탄력섬유 염색을 통한 조직학적 평가에서는 UV에 의해 밀도가 엉성하고 배열이 불규칙적이던 섬유들이 개선된 것을 관찰할 수 있었다. 이상의 결과로 보아 HA를 경구 투여 시 UV로부터 유도된 광노화 억제 및 피부주름 개선에 효능이 있음을 확인하였다.

두날리엘라 살리나 추출물의 피부 열노화 억제 효과 (Inhibitory Effects of Dunaliella salina Extracts on Thermally-Induced Skin Aging)

  • 주지혜;석지현;홍인기;김남경;최은미
    • 대한화장품학회지
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    • 제42권1호
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    • pp.57-64
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    • 2016
  • 자외선과 유사하게 열에 의한 콜라겐 분해와 비정상적인 탄력섬유의 축적을 증가시키는 현상을 열노화라 칭한다. 두날리엘라 살리나는 녹조류로 베타카로틴을 많이 함유하고 있어 건강식품으로 많이 이용되고 있으나 열에 의해 유도된 피부노화에서의 효능은 알려진 바 없다. 본 연구에서는 두날리엘라 살리나 에탄올 추출물의 항-열노화 효능을 확인하였다. 열을 가한 피부섬유아세포를 이용하여 MMP-1과 type I procollagen 발현을 ELISA를 이용해 확인하였다. 두날리엘라 살리나 추출물이 열에 의해 증가된 MMP-1 단백질 발현량을 감소시키며, type I procollagen 단백질 발현량은 증가시킨다는 사실을 확인하였다. 추가적으로, 두날리엘라 살리나 추출물에 의해 콜라겐 합성 과정에 관여하는 것으로 알려진 HSP47 mRNA의 발현이 증가함을 확인하였다. 또한, 두날리엘라 살리나 추출물이 염증매개인자(TGF-${\beta}$, IL-12 등)의 발현을 감소시킴을 확인하였다. 다음으로 두날리엘라 살리나 추출물이 탄력섬유의 구성성분인 tropoelastin과 fibrillin-1 단백질 발현과 MMP-12 발현 조절을 통해 열에 의해 유도된 일광탄력섬유증을 조절하는 효능을 확인하였다. 이 결과를 통해 두날리엘라 살리나 추출물이 열에 의해 유도된 피부열노화를 효과적으로 예방함을 확인하였다.

Forward Gene Mutation Assay of Seven Benzophenone-type UV Filters using L5178Y Mouse Lymphoma Cell

  • Jeon, Hee-Kyung;Sarma, Sailendra Nath;Kim, Youn-Jung;Ryu, Jae-Chun
    • Molecular & Cellular Toxicology
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    • 제3권1호
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    • pp.23-30
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    • 2007
  • The effects of high energy short wave solar radiation on human skin have received much publicity as the major cause of accelerated skin ageing and of skin cancers. To meet public demand, the cosmetic industry has developed sun protection factor products, which contain a variety of so-called "UV filters", among others benzophenone (BP) and its metabolites are the widely used UV filters. UV filters are also used to prevent UV light from damaging scents and colors in a variety of cosmetics products and to protect of plastic products against light-induced degradation. There are many variants of BP in use. In this respect, to regulate and to evaluate the hazardous effect of BP-type UV filters will be important to environment and human health. The genotoxicity of 7 BP-type UV filters was evaluated in L5178Y $(tk^{+/-})$ mouse lymphoma cells in vitro. BP, benzhydrol, 4-hydroxybenzophenone 2-hydroxy-4-methoxybenzophenone and 2, 4-dihydroxybenzophenone did not induce significant mutation frequencies both in the presence and absence of metabolic activation system. 2, 2'-Dihydroxy-4-methoxybenzophenone appeared the positive results at the highest dose, i.e. 120.4 ${\mu}g/mL$ only in the absence of metabolic activation system. And also, 2, 3, 4-trihydroxybenzophenone revealed a significant increase of mutation frequencies in the range of 138.1-207.2 ${\mu}g/mL$ in the absence of metabolic activation system and 118.3-354.8 ${\mu}g/mL$ in the presence of metabolic activation system. Through the results of MLA with 7 BP-type UV filters in L5178Y cells in vitro, we may provide the important clues on the genotoxic potentials of these BP-type UV filters.

Downregulation of $\textrm{NF}_{-{\kappa}}\textrm{B}$ activation in human keratinocytes by melanogenic inhibitors

  • Ahn, Kwang-Seok;Lee, Jinseon;Kim, Yeong-Shik
    • 대한화장품학회:학술대회논문집
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    • 대한화장품학회 2003년도 IFSCC Conference Proceeding Book I
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    • pp.780-803
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    • 2003
  • Exposure of skin cells, particularly keratinocytes to various nuclear factor-kappaB ($\textrm{NF}_{-{\kappa}}\textrm{B}$) activators [e.g. tumor necrosis factor-$\alpha$, interleukin-1, lipopolysaccharides, and ultraviolet light] leads to phosphorylation and degradation of the inhibitory protein, $\textrm{I}_{{\kappa}}\textrm{B}$. Liberated $\textrm{NF}_{-{\kappa}}\textrm{B}$ is translocated into the nucleus where it can change or alter expression of target genes, resulting in the secretion of extracellular signaling molecules including melanotrophic factors affecting melanocyte. In order to demonstrate the possible role of $\textrm{NF}_{-{\kappa}}\textrm{B}$ activation on the synthesis of melanotrophic factors from the keratinocytes, the activities of $\textrm{NF}_{-{\kappa}}\textrm{B}$ induced by melanogenic inhibitors (MIs) were determined in human HaCaT keratinocytes transfected with $\textrm{pNF}_{-{\kappa}}\textrm{B}$-SEAP-NPT plasmid. Transfectant cells released the secretory alkaline phosphatase (SEAP) as a transcription reporter in response to the $\textrm{NF}_{-{\kappa}}\textrm{B}$ activity and contain the neomycin phosphotransferase (NPT) gene for the dominant selection marker for geneticin resistance. MIs such as niacinamide, kojic acid, hydroquinone, resorcinol, arbutin, and glycolic acid were preincubated with transfectant HaCaT cells for 3 h and then ultraviolet B (UVB) was irradiated. $\textrm{NF}_{-{\kappa}}\textrm{B}$ activation was measured with the SEAP reporter gene assay using a fluorescence detection method. Of the Mis tested, kojic acid ($IC_{50}$/ = 60 $\mu$M) was found to be the most potent inhibitor of UVB-upregulating $\textrm{NF}_{-{\kappa}}\textrm{B}$ activation in transfectant HaCaT cells, which is followed by niacinamide ($IC_{50}$/= 540 $\mu$M). Pretreatment of the transfectant HaCaT cells with the Mis, especially kojic acid and niacinamide, effectively lowered $\textrm{NF}_{-{\kappa}}\textrm{B}$ binding measured by electrophoretic mobility shift assay. Furthermore, these two inhibitors remarkably reduced the secretion level of IL-6, one of melanotrophic factors, triggered by UV-radiation of the HaCaT cells. These observations suggest that Mis working at the in vivo level might act partially through the modulation of the synthesis of melanotrophic factors in keratinocyte.

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X線照射에 따르는 Deoxycytidineuria와 CdR-aminohydrolase의 活性變化와의 連關性 (Correlation between Deoxycytidineuria and CdR-aminohydrolase Activity following X-Irradiation)

  • Man Sik kang;Rhee, Juong-Gile;Cho, Joong-Myung
    • 한국동물학회지
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    • 제18권4호
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    • pp.163-172
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    • 1975
  • 생쥐에 400 및 800 R의 X線을 一時全身照射한 뒤, 몇가지 臟器에서 Dische 陽性物質의 放出量과 CdR-aminohydrolase의 活性變化 및 尿중의 CdR量을 照射후의 時間經過에 따라 측정하여 放射線照射후 deoxycytidineuria의 增加機構의 一面을 究明하려고 시도했다. CdR-aminohydrolase의 活性度는 照射후 1時間째에 小腸과 肝에서 顯著한 감소를 보였으며, 5$\\sim$12시간 사이에 정상水準으로 복귀되었다가 3日째에 最大의 증가를 나타냈다. 한편, 脾臟과 血液의 경우는 對照群과 照射群에서 모두 극미한 活性만이 관찰되었다. Dische 陽性物質의 放出量은 小腸의 경우 照射후 3$\\sim$12시간 사이에 증가를 보였으며 6$\\sim$9시간에 最大値를 나타냈다. 이에 반해서 肝, 脾臟 및 賢臟의 경우는 小腸에 비해 1/20 이하에 불과하였으며, 이들 조직은 照射후 증가하는 deoxycytidineuria에 직접 寄與하지는 않는 것으로 생각된다. Deoxycytidineuria는 照射후 9$\\sim$12시간에 最大値를 보였는데, 이의 相當量이 小腸에 연유하는 것으로 믿어지고, 특히 小腸의 CdR-aminohydrolase의 活性度의 변화와 깊은 關連이 있는 것으로 생각된다. 즉 放射線照射후 DNA分解産物중 CdR이 CdR-aminohydrolase의 活性이 격감하는 시기에 조직으로부터 血液으로 放出되고, 血液내에서는 별다른 量的변화를 거치지 않고 尿에 섞여 排泄되는 것으로 思料된다.

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Microprogation And Environment Conditions Affecting On Growth Of In Vitro And Ex Vitro Of A. Formosanus Hay

  • Ket, Nguyen-Van;Paek, Kee-Yoeup
    • 한국자원식물학회:학술대회논문집
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    • 한국자원식물학회 2002년도 심포지엄
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    • pp.29-30
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    • 2002
  • The goal of this research was to develop the effectiveness of in vitro culture method for A. formosanus and study the environment in vitro conditions affecting on growth. The first series of experiments were examined to investigate the response of three different basal media, MS (Murashige and Skoog, 1962), Knudson (KC; Knudson, 1946) and modified hyponex on growth and multiplication during in vitro culture. Multiple shoot proliferation was induced in shoot tip explants on Hyponex (H3) media supplemented with BA (1 mg1$\^$-1/) or TDZ (1-2 mg1$\^$-1/). Addition of activated charcoal (1%) to the TDZ containing medium promoted rapid shoot tip proliferation (11.1 shoots per explant) but the same medium had an opposite effect resulting in poor proliferation in the nodal explants. However, the regenerated shoots had slow growth rate and failed to elongate. This problem was overcome by transferring the shoot clumps to a hormone free H3 media supplemented with 2% sucrose and 0.5% activated charcoal. Using bioreactor culture for scaling up was also shown the best way for multiple shoot induction and growth of this plant. The second series of experiments was studied to investigate the effect of physical environment factors on growth of in vitro plantlets. The Anoectochilus formosanus plantlets were cultured under different air exchange rate (0.1, 0.9, 1.2h$\^$-1/), without sucrose or supplement 20g.1$\^$-1/ (photoautotrophic or photomixotrophic, respectively), and different photosynthesis photon flux (40, 80, 120 ,${\mu}$mol.m$^2$.s$\^$-1/- PPF). Under non-enrichment CO$_2$ treatment, slow growth was observed in photoautotrophical condition as compared with photomixotrophical condition on shoot height, fresh weigh and dry weight parameters; High air exchange (1.2.h-l) was found to be inadequate for plant growth in photomixotrophical condition. On the contrary, under CO$_2$, enrichment treatment, the plant growth parameters were sharply (visibly) improved on photoautotrophic treatments, especially on the treatment with air exchange rate of 0.9.h-1. The growth of plant in photoautotrophic condition was not inferior compared with photomixotrophic, and the best growth of plantlet was observed in treatment with low air exchange rate (0.9.h-1). Raising the PPF level from 80 to 120${\mu}$mol.m$\^$-2/.s$\^$-1/ decreased the plant height, particularly at 120${\mu}$mol.m$\^$-2/.s$\^$-1/ in photoautotrophic condition, fresh weight and dry weight declined noticeably. At the PPF of 120${\mu}$mol.m$\^$-2/,s$\^$-1/, chlorophyll contents lowed compared to those grown under low PPF but time courses of net photosynthesis rate was decreased noticeably. Light quality mainly affected morphological variables, changes of light quality also positively affected biomass production via changes in leaf area, stem elongation, chlorophyll content. Plant biomass was reduced when A. formosanus were grown under red LEDs in the absence of blue wavelengths compare to plants grown under supplemental blue light or under fluorescent light. Stem elongation was observed under red and blue light in the present experiment. Smaller leaf area has found under blue light than with other lighting treatments. Chlorophyll degradation was more pronounced in red and blue light compared with white light or red plus blue light which consequent affected the photosynthetic capacity of the plant. The third series of experiment were studied to investigate the effect of physical environment factors on growth of ex vitro plants including photosynthesis photon flux (PPF), light quality, growing substrates, electrical conductivity (EC) and humidity conditions. In the present experiments, response of plant on PPF and light quality was similar in vitro plants under photosynthesis photon flux 40${\mu}$mol.m,$\^$-2/.s$\^$-1/ and white light or blue plus red lights were the best growth. Substrates testing results were indicated cocopeat or peat moss were good substrates for A. formosanus growth under the greenhouse conditions. In case of A. formosanus plants, EC is generally maintained in the range 0.7 to 1.5 dS.m-1 was shown best results in growth of this plant. Keeping high humidity over 70% under low radiation enhanced growth rate and mass production.

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