• 생명과학회지
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• 제21권7호
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• pp.969-975
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• 2011

본 연구에서는 식물뿌리의 굴중성 반응에 있어서 식물호르몬과 AtEXPA3 유전자와의 관계를 밝히고자 하였다. AtEXPA3 유전자의 RT-PCR을 통한 발현분석 결과 잎, 근출엽, 뿌리 꽃 등 생장이 활발한 조직에서 발현률이 높게 나타났으며, 굴중성 자극과 BRs, IAA에 의해서도 발현이 증가되었다. 또한 ethylene 생합성 저해제인 AVG를 처리하면 굴중성 반응이 현저히 억제되었는데 이는 ethylene 그 자체도 BR과 IAA처럼 굴중성을 촉진시키는 활성을 갖고 있음을 의미한다. 한편 호르몬을 처리하지 않은 AtEXPA3 RNAi mutant에서 굴중성 반응이 억제되는 현상은 애기장대 뿌리의 생장에 관여하는 AtEXPA3의 조절 인자로 BRs, auxin, ethylene 등의 식물호르몬이 관여하고 있음을 나타낸다. 아울러 BRs signaling mutant에서 변화된 굴중성(bri1-301, bak1에서 감소, BRI-GFP에 서 증가) 반응의 감소와 증가는 굴중성 반응이 BRs의 신호전달 과정을 통하여 일어남을 의미한다. 결론적으로 애기장대 뿌리의 굴중성 반응은 식물호르몬에 의한 AtEXPA3 유전자의 발현 증가의 결과로 인해 애기장대 뿌리의 생장이 촉진되어 나타나는 결과라 하겠다.

• Journal of Plant Biotechnology
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• 제30권2호
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• pp.161-165
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• 2003

The effect of NAA and Benzyladenine(BA) for determination times on the formation of adventitious shoots, roots trichmoes and calli in MS basal medium was investigated in leaf segments from ecotype 'Nosses' of Arabidopsis thalliana. Adventitious shoots, roots, trichomes and calli were formed fromed from leaf segments in a wede range of NAA and BA. The optimal combination of hormones for adventitious shoots formation, 20mg/L NAA for trichome formation, 100mg/L for callus formation. Inductive times for formation of adventitious shoots, roots, trichomes and calli were determined at 14, 4, 6 and 18 days respectively by periodical transfer of leaf segments from hormines containing media to hormone free medium.

• Molecules and Cells
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• 제45권5호
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• pp.294-305
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• 2022

E3 ligase BRUTUS (BTS), a putative iron sensor, is expressed in both root and shoot tissues in seedlings of Arabidopsis thaliana. The role of BTS in root tissues has been well established. However, its role in shoot tissues has been scarcely studied. Comparative transcriptome analysis with shoot and root tissues revealed that BTS is involved in regulating energy metabolism by modulating expression of mitochondrial and chloroplast genes in shoot tissues. Moreover, in shoot tissues of bts-1 plants, levels of ADP and ATP and the ratio of ADP/ATP were greatly increased with a concomitant decrease in levels of soluble sugar and starch. The decreased starch level in bts-1 shoot tissues was restored to the level of shoot tissues of wild-type plants upon vanadate treatment. Through this study, we expand the role of BTS to regulation of energy metabolism in the shoot in addition to its role of iron deficiency response in roots.

• Journal of Plant Biotechnology
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• 제47권4호
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• pp.283-288
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• 2020

Although the evolution of Arabidopsis thaliana and humans diverged approximately 1.6 billion years ago, recent studies have demonstrated that protein function and cellular processes involved in disease response remain remarkably conserved. Particularly, γ-secretase, a multisubunit protein complex that participates in intramembrane proteolysis (RIP) regulation, is also known to mediate the cleavage of more than 80 substrates including the amyloid precursor protein (APP) and the Notch receptor. Although the genes (PS1/2, APH-1, PEN-2, and NCT) coding for the γ-secretase complex components are present in plant genomes, their function remains largely uncharacterized. Given that the deposition of 42 amino acid long amyloid-β peptides (hAβ₄₂) is thought to be one of the main causes of Alzheimer's disease, we aimed to examine the physiological effects of hAβ₄₂ peptides on plants. Interestingly, we found that Arabidopsis protoplast death increased after 24 h of exposure to 3 or 5 µM hAβ₄₂ peptides. Furthermore, transgenic Arabidopsis plants overexpressing the hAβ₄₂ gene exhibited changes in primary root length and silique phyllotaxy. Taken together, our results demonstrate that hAβ₄₂ peptides, a metazoan protein, significantly affect Arabidopsis protoplast viability and plant morphology.

• 생명과학회지
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• 제22권4호
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• pp.559-564
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• 2012

식물생장과 발달에 중요한 역할을 하는 phytochrome이 ethylene 생합성에 미치는 영향을 조사하기 위하여 여러 빛 조건에서 키운 phyA, phyB, phyAB에서 ethylene 생합성과 생합성에 관여하는 enzyme activity를 측정하였다. White light에서 키웠을 때 모든 mutant에서 ethylene 생합성이 감소되었다. 특히 double mutant에서는 wild type과 비교하여 37%가 감소하였다. Dark에서 키웠을 때에는 wild type만 감소하였고, mutant에서는 감소효과가 나타나지 않았다. Red light에서 키웠을 때 double mutant에서 급격한 감소가 일어났다. Far-red light 에서 키웠을 때는 phyB만 감소가 일어나지 않았다. Ethylene 생합성에 관여하는 enzyme인 ACO 활성 패턴과는 달리ACS 활성 패턴은 ethylene 생성 패턴과 유사하게 나타났다. 이 결과를 바탕으로 ethylene 생합성에는 phytochrome A와 B 모두 중요한 작용을 하며 특히 $P_r$ 형태의 phytochrome이 ethylene 생성량을 조절한다는 것을 제시한다. 또한 phytochrome은 ethylene 생합성 단계에서 AdoMet가 ACC로 전환되는 단계에서 조절하는 것을 제시한다.

• Plant Biotechnology Reports
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• 제4권1호
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• pp.53-59
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• 2010

A specific deleted version of ARABIDOPSIS RESPONSE REGULATOR1 (ARR1) lacking the signal receiver domain (1.152 amino acids)-coding sequence, referred to as $ARR1{\Delta}DDK$, was amplified using Arabidopsis thaliana cDNA prepared from adult leaves and transferred into the genome of Nicotiana tabacum cv. Samsun under the transcriptional control of a ${\beta}$-estradiol-inducible expression system. The ectopic expression of $ARR1{\Delta}DDK$ affected the morphology of transgenic seedlings and their segments in vitro. In the presence of an inducer, ${\beta}$-estradiol, ectopic expression of $ARR1{\Delta}DDK$ induced only the formation of soft, pseudo-bulbous tissue in the root tip region of intact seedlings, which appeared similar to callus generated on a hypocotyl segment in the presence of 2,4-D and 6-benzyladenine (BA), both at $1\;{\mu}M$. Those callus tissues on the root tip region could not generate shoots unless $1\;{\mu}M$ BA was supplied. In segment culture, ectopic expression of $ARR1{\Delta}DDK$ induced calluslike tissue around the cut-end of cotyledon and hypocotyl segments with occasional shoot formation, suggesting that the expression of $ARR1{\Delta}DDK$ could substitute for the effects of cytokinin on these segments. Additionally, treatment with only ${\beta}$-estradiol induced NtWUS, a WUS ortholog in tobacco, which was detected during the process of callus tissue formation in the root tip region and also in cotyledon or hypocotyl segments. These findings suggest that the NtWUS might be associated in the transdifferentiation process caused by the functional regulation of $ARR1{\Delta}DDK$ in transgenic tobacco seedlings.

• Journal of Ginseng Research
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• 제48권2호
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• pp.220-228
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• 2024

Background: Panax ginseng, one of the valuable perennial medicinal plants, stores numerous pharmacological substrates in its storage roots. Given its perennial growth habit, organ regeneration occurs each year, and cambium stem cell activity is necessary for secondary growth and storage root formation. Cytokinin (CK) is a phytohormone involved in the maintenance of meristematic cells for the development of storage organs; however, its physiological role in storage-root secondary growth remains unknown. Methods: Exogenous CK was repeatedly applied to P. ginseng, and morphological and histological changes were observed. RNA-seq analysis was used to elucidate the transcriptional network of CK that regulates P. ginseng growth and development. The HISTIDINE KINASE 3 (PgHK3) and RESPONSE REGULATOR 2 (PgRR2) genes were cloned in P. ginseng and functionally analyzed in Arabidopsis as a two-component system involved in CK signaling. Results: Phenotypic and histological analyses showed that CK increased cambium activity and dormant axillary bud formation in P. ginseng, thus promoting storage-root secondary growth and bud formation. The evolutionarily conserved two-component signaling pathways in P. ginseng were sufficient to restore CK signaling in the Arabidopsis ahk2/3 double mutant and rescue its growth defects. Finally, RNA-seq analysis of CK-treated P. ginseng roots revealed that plant-type cell wall biogenesis-related genes are tightly connected with mitotic cell division, cytokinesis, and auxin signaling to regulate CK-mediated P. ginseng development. Conclusion: Overall, we identified the CK signaling-related two-component systems and their physiological role in P. ginseng. This scientific information has the potential to significantly improve the field-cultivation and biotechnology-based breeding of ginseng.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2018년도 춘계학술발표회
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• pp.17-17
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• 2018

Panax ginseng Meyer is a perennial medicinal plant, the roots of which has been used in the traditional formulations in Oriental countries. To understand its floral transition, we isolated Flowering Locus T (FT) from ginseng, the bioinformatics analysis of PgFT has revealed a considerable homology to the higher plants, with the essential amino acids for FT function are conserved. The phylogenetic analysis has shown that the PgFT is belonged to the shrub classes of plants and closest kin to Jatropha curcas FT. The expression profiling from juvenile (2-year-old) were abundant in leaves as well as in root and was concentrated in the secondary leaflet and stem bottom in adult (4-year-old) ginseng plant tissues, moreover PgFT transcript displayed photoperiod dependent oscillation. The ectopic expression of PgFT in Arabidopsis thaliana, exhibit precocious flowering and several floral pathway integrators were up-regulated, interestingly their root length was increased in the transgenic seedlings. Therefore, we could conclude that PgFT encodes a florigen that acts as a key regulator in the flowering pathway in ginseng and hypothesize that, it might involve in the underground organ development as well. We believe our finding could provoke future studies on the physiology and development in P. ginseng.

• 식물병연구
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• 제16권1호
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• pp.81-85
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• 2010

산성비 수준의 고농도 수소이온 스트레스인 pH 5.6-4.0 처리는 애기장대 생장에 크게 해를 주지 않았으며 강산성인 pH 3.5 이하에서 수소이온 농도가 높아질수록 식물 뿌리 및 줄기의 생장이 위축되었으며 특히 뿌리가 줄기보다 더 민감하게 반응하였다. 엽록소 함량은 pH 5.6-4.0까지 pH가 낮아질수확 증가히였다. pH 4.0에서 내려갈수록 점진적으로 엽록소 함량이 감소되는 경향을 보였으며 카로티노이드도 엽록소와 같은 경향을 보였으나 pH 3.5에서 함량이 가장 높았다. 안토시아닌은 pH가 낮아질 수록 계속 증가하여 pH 3.0에서 가장 많이 축적되었으며 pH 2.5에서는 급격히 감소되었다. 스트레스 강도가 세어 질수록 엽록소 대비 식물체내 카혹티노이드 및 안토시아닌 함량이 증가한다는 것은 엽록소를 보호하기 위한 식물의 생리적 반응으로 여겨진다. 그러나 안토시아닌과 카로티노이드는 수소이온 농도에 따른 식물체내 함량의 변화가 상이하여서 고수소이온 스트레스에서 식물의 보호하는 기작이 다를 것으로 에상된다.

• The Plant Pathology Journal
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• 제33권6호
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• pp.614-618
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• 2017

The root-knot nematode Meloidogyne incognita infects a variety of plants, including Arabidopsis thaliana. During migration, root-knot nematodes secrete different proteins to modify cell walls, which include pectolytic enzymes. However, the contribution of host cell wall proteins has not been described during this process. The function of two DUF642 cell wall proteins, BIIDXI (BDX, At4g32460) and TEEBE (TEB, At2g41800), in plant development could be related to the regulation of pectin methyl esterification status in the cell walls of different tissues. Accordingly, the expression of these two genes is up-regulated by auxin. BDX and TEB were highly induced during early M. incognita inoculation. Moreover, cell wall localization of the proteins was also induced. The cell wall localization of BDX and TEB DUF642 proteins during M. incognita early inoculation suggested that these two proteins could be involved in the regulation of the degree of pectin methylation during cell separation.