• 식물병연구
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• 제29권3호
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• pp.234-242
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• 2023

이른 봄에 개나리 꽃잎과 잎에 수침상 병반이 나타나서 조직이 괴저하며 마르고 증상이 가지까지 확산되었다. 감염된 가지에는 궤양이 생기며 5월 초부터 윗부분이 말라 죽는데, 가지 기부까지 말라 죽는 경우는 매우 드물었다. 마름 증상을 보이는 가지 조직으로부터 균을 분리하여 병원성을 확인하였다. 대부분의 시료로부터 같은 균이 분리되었는데, potato dextrose agar 배지에서 흰색 균총을 만들었으며 23℃에서 생육이 가장 활발하였고 크기가 다양한 균핵을 많이 만들었다. 개나리의 각 기관에 균사와 균핵 현탁액을 접종한 병원성 검정에서 병원균은 꽃을 감염하며, 잎이나 가지는 감염하지 않는 것으로 나타났다. 꽃에 나타난 증상은 시간이 지남에 따라 잎과 가지로 확산되며 감염 조직을 고사시켰다. 병원균을 동정하기 위하여 ITS, LSU, Tub2, CAL 등 네 가지 유전자의 염기서열을 분석한 결과 Septotinia속으로 동정되었다. 본 연구는 개나리 가지마름병(가칭)에 대한 국내 첫 보고인 동시에 Septotinia속이 식물병원균임을 밝히는 국내 첫 보고이다.

• 식물조직배양학회지
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• 제22권1호
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• pp.7-11
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• 1995

종자발아 후 5일된 양배추 그린챌린져 배축으로부터 분리된 원형질체로부터 완전한 식물체를 재분화 시켰다. Kao배지와 B5 배지를 기본으로 한 기존의 몇가지 배지에서 원형질체를 배양한 결과 변형시킨 BS배지에서 Plating efficiency는 낮았으나 식물체 재분화율은 가장 높게 나타나 거의 원형질체 배양배지 조성, 생장조절제 농도 등이 재분화에 상당한 영향을 주는 것으로 나타났다. 또한 사용된25가지 종류의 재분화 배지중에서 MS배지에 l% sucrose zeatin 3 mg/L, 1.6% T.C. agar가 첨가된 배지에서 재분화율이 가장 좋았다. 식물체 재분화에 미치는 PVP (polyvinyl Polypyrrolidone)와 agar 농도의 영향으로는 PVP는 큰 효과가 없었고 agar농도를 1.6%로 2배 증가시켰을 때 재분화율이 다소 높아졌다. 현재까지 재분화된 식물체는 150여 개체로서 포장에서 재배중에 있다.

• 아시안잔디학회지
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• 제22권2호
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• pp.141-148
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• 2008

본 연구는 과학적인 잔디관리의 기초자료를 얻고자 월동 전 잔디의 양분함량을 분석하였다. 월동 전 크리핑 벤트그래스, 켄터키 블루 그래스 및 한국잔디의 단위면적당 건물 중은 지상부 비율은 각각 12%, 27%, 25% 이고, 지하부 비율은 각각 88%, 73%, 75% 이었다. 잔디 조직 중 함유된 다량원소의 순서는 N > K > Ca > P > Mg > Na 이며, 질소, 칼륨, 칼슘, 인의 함량이 90%를 차지하였다. 잔디 식물체의 조직 부위별 함유된 양분 비율은 켄터키 블루그래스, 벤트그래스 및 한국잔디의 지상부에는 각각 28%, 17%, 34%, 지하부에는 각각 72%, 83%, 66%를 함유하고 있었다. 이러한 결과들을 통해 월동 전 잔디는 조직중 전체 함유 양분의 70% 정도를 지하부에 저장하고 있음을 알 수 있었고, 월동 준비 전 크리핑 벤트그래스, 켄터키 블루그래스 및 한국잔디를 관리함에 있어 질소, 인산, 가리 뿐 아니라 칼슘비료의 시비도 필요함을 알 수 있었다.

• 한국초지조사료학회지
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• 제41권3호
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• pp.162-167
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• 2021

Aluminum (Al) stress in acidic pH is known to decrease the growth and productivity of alfalfa. However, not much is known about how the application of silicon (Si) affects the Al stress response in alfalfa. This study was conducted to evaluate the effect of exogenous application of Si on the growth of alfalfa seedlings exposed to Al stress in pots. Alfalfa seedlings grown in pots for 2 weeks were treated either Al stress (pH 4.0, 0.2 mM Al) or Al stress + Si (1 mM) for 5 days, lengths and biomass of shoot and root, and chlorophyll and carotenoid contents in leaf tissues were analyzed respectively. Al stress treatment inhibited shoot and root growth, and decreased fresh and dry weights, and chlorophyll content in leaves, but increased carotenoid content. In contrast, when alfalfa seedlings treated with Al stress combined with Si, delayed growth caused by Al stress of shoot and root of alfalfa seedlings was restored, dry weight was increased and chlorophyll content of leaf tissue was increased, but carotenoid content was decreased. These results suggest that Si has a function of alleviating Al toxicity in alfalfa, of which it exhibits a mitigating effect by a function that overlaps with some of the intracellular functions of carotenoids.

• 한국작물학회지
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• 제38권4호
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• pp.366-370
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• 1993

본 연구는 기내에서 두릅의 잎조직배양을 통한 효율적인 종묘대량증식체계를 확립하기 위한 기초연구로서 엽내으로부터 캘루스 유기 및 식물체 재분화를 시도한 결과이다. 1. 유연조직으로부터 캘루스 유기는 1.0mg/1 Thidiazuron 첨가배지에서 70%의 유기율을 보였다. 2. 0.1～0.2mg/1 Dicamba 및 1.0mg/1 Picloram 첨가가 캘루스의 증식에 효과가 있었다. 3. 호르몬 첨가배지에서는 식물체 재분화가 이루어지지 않은 반면 Hormon-free 배지에서 shoot 및 root의 분화가 이루어져 완전한 식물체를 얻었다.

• The Plant Pathology Journal
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• 제21권4호
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• pp.355-360
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• 2005

Sulfur, an important component of plants, is regulated by a variety of stresses in sulfate assimilation and metabolism. Increase has been observed in the expression of O-acetylserine(thiol)lyase (OASTL) through two-dimensional electrophoresis with the shoot tips of Arabidopsis infected by beet severe curly top geminivirus (BSCTV). With the three- to six-fold increases in the transcript expression of OASTL, serine acetyltransferase (SAT) and $\gamma$-glutmylcysteine synthetase (GSH) were induced over the mock-inoculated organization in each organization through real-time RT-PCR analysis. The expression of those genes might affect the accumulation of anthocyanin in symptomatic tissues and the induction of abnormal callus-like structures formed by additional cell divisions as typical disease symptoms of BSCTV-infected Arabidopsis. This is the first report to describe the collaborative induction of OASTL, SAT, and GSH in virus-infected plants. The changed expressions of OASTL, SAT, and GSH in Arabidopsis infected with BSCTV raises new aspects regarding the biological function of symptomatic tissues related to sulfate metabolism.

• Journal of Ginseng Research
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• 제5권1호
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• pp.35-40
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• 1981

Explants of mature root tissues and calli derived from root and cotyledon of Panax ginseng were cultured in vitro on Murashige and Skoog medium supplemented with 2, 4-dichlorophen-oxyacetic acid(3,4-D), naphthaleneacetic acid(NAA), benzyladenine, and gibberellic acid to assess their capacity to regenerate organs. Root formation at high percentage (46.2-61.1%) was obtained 20-30 days after culturing on media supplemented with combinations of NAA(5 mg/l) and kinetin (1 mg/l), And calli derived from cotyledon produced numerous embryoids in media($\frac{1}{2}$MS) containing 2,4-D(0.5 mg/l) and kinetin (0.5 mg/l). Reculture of these embryoids in media($\frac{1}{2}$MS) enriched with 1 mg/l of benzyladenine and 1 mg/l of gibberellic acid resulted in more plantlet regeneration.

• Journal of Plant Biology
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• 제29권2호
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• pp.129-133
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• 1986

Transections of the stem region close to the shoot apex show the occurrence of an outer, complete ring of procambium and an inner group of discrete procambial strands. From the outer ring, small, discrete vascular bundles and vascular cambium originate, while the inner group forms the discrete, medullary vascular bundles with intrafascicular cambium. Secondary thickening is essentially due to the activity of the cylinder or complete ring of vascular cambium that originates from the procambium. The medullary intrafascicular cambia also form some secondary tissues. The vascular cambium produces secondary xylem inwards and secondary phloem outwards as in the normal secondary thickening process. The distinctive feature, however, is perpetual discreteness of the medullary vascular bundles. No successive series of cambia or secondary vascular bundles are found.

• Journal of Plant Biology
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• 제39권4호
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• pp.249-256
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• 1996

Beet curly top virus is the DNA virus that is providing useful for basic studies of the infection of Arabidopsis thaliana with viral host and provides a system for studying both resistance and the molecular basis of symptom development. An importnat aspect of symptom development observed in BCTV-infected A. thaliana (ecotype Sei-O) was the induction of cell division on phloem and surrounding cortex cells. Analysis of the expression of GUS reporter gene activity in transgenic plants containing constructs with promoter of the auxin-inducible saur gene showed that saur promoter activity was induced concomitantly in symptomatic tissues at the inflorescence shoot tips of the transgenic lines. The auxin sensitivity tests showed that hypersusceptible ecotype, Sei-O produced more amounts of callus than susceptible ecotype, Col-O. These studies indicated that changes in auxin concentration were involved in the induction of cell division in BCTV-infected plants and clearly demonstrated that there was a strong correlation between auxin-induced gene expression and the activation of cell division.

• Journal of Ecology and Environment
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• 제45권3호
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• pp.143-151
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• 2021

Background: Plants are able to optimize defense responses induced by various herbivores, which have different feeding strategies. Local and systemic responses within a plant after herbivory are essential to modulate herbivore-specific plant responses. For instance, leaf-chewing herbivores elicit jasmonic acid signaling, which result in the inductions of toxic chemicals in the attacked leaf (tissue-specific responses) and also in the other unattacked parts of the plant (systemic responses). Root herbivory induces toxic metabolites in the attacked root and alters the levels of transcripts and metabolites in the unattacked shoot. However, we have little knowledge of the local and systemic responses against stem-boring herbivores. In this study, we examined the systemic changes in metabolites in the wild tobacco Nicotiana attenuata, when the stem-boring herbivore Trichobaris mucorea attacks. Results: To investigate the systemic responses of T. mucorea attacks, we measured the levels of jasmonic acid (JA), JA-dependent secondary metabolites, soluble sugars, and free amino acids in 7 distinct tissues of N. attenuata: leaf lamina with epidermis (LLE), leaf midrib (LM), stem epidermis (SE), stem pith (SP), stem vascular bundle (SV), root cortex with epidermis (RCE), and root vascular bundle (RV). The levels of JA were increased in all root tissues and in LM by T. mucorea attacks. The levels of chlorogenic acids (CGAs) and nicotine were increased in all stem tissues by T. mucorea. However, CGA was systematically induced in LM, and nicotine was systematically induced in LM and RCE. We further tested the resource allocation by measuring soluble sugars and free amino acids in plant tissues. T. mucorea attacks increased the level of free amino acids in all tissues except in LLE. The levels of soluble sugars were significantly decreased in SE and SP, but increased in RV. Conclusions: The results reveal that plants have local- and systemic-specific responses in response to attack from a stem-boring herbivore. Interestingly, the level of induced secondary metabolites was not consistent with the systemic inductions of JA. Spatiotemporal resolution of plant defense responses against stem herbivory will be required to understand how a plant copes with attack from herbivores from different feeding guilds.