• Molecules and Cells
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• 제19권3호
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• pp.342-349
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• 2005

Cytokinins are adenine derivatives that regulate numerous plant growth and developmental processes, including apical and floral meristem development, stem growth, leaf senescence, apical dominance, and stress tolerance. However, not much is known about how cytokinin biosynthesis and metabolism is regulated. We identified a novel Arabidopsis gene, ALL, encoding an aldolase-like enzyme that regulates cytokinin signaling. An Arabidopsis mutant, all-1D, in which ALL is activated by the nearby insertion of the 35S enhancer, exhibited extreme dwarfism with rolled, dark-green leaves and reduced apical dominance, symptomatic of cytokinin-overproducing mutants. Consistent with this, ARR4 and ARR5, two representative primary cytokinin-responsive genes, were significantly induced in all-1D. Whereas SHOOT MERISTEMLESS (STM) and KNAT1, which regulate meristem development, were also greatly induced, expression of REV and PHV that regulate lateral organ polarity was inhibited. ALL encodes an aldolase-like enzyme that belongs to the HpcH/HpaI aldolase family in prokaryotes and is down-regulated by exogenous cytokinin, possibly through a negative feedback pathway. We propose that ALL is involved in cytokinin biosynthesis or metabolism and acts as a positive regulator of cytokinin signaling during shoot apical meristem development and determination of lateral organ polarity.

• 한국작물학회지
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• 제40권3호
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• pp.334-339
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• 1995

옥수수의 육성과정이나 교잡종 생산시에 암술봉투를 씌우기 전에 상부이삭이 출사하는 경우에는 출사한 개체를 버리지 않고 출사한 이삭을 제거하면 하부이삭이 발육하므로 종자 생산을 기대 할 수 있다. 본 실험은 7개의 자식계통을 공시하여 출사된 상부이삭의 제거가 하부이삭의 개화와 종자생산에 대한 반응을 검토하고자 실시하였으며 그 결과를 요약하면 다음과 같다. 1. 상부이삭을 제거하였을 때 하부이삭의 출사기는 상부이삭보다 4일 정도 지연되었으며 자식계통간에 차이가 있었다. 2. 하부이삭의 적장은 상부이삭에 비하여 평균 36% 정도 짧았으며, 자식계통 NC246은 하부 이삭이 발육출사되지 않아 자식계통간의 차이를 나타냈다. 3. 하부이삭의 이삭열수와 열당립수는 각각 28%, 37% 적었고 수당립수는 43% 적었으며. 자식계통간의 감소 범위는 0∼82% 이었다. 4. 수양구성 요소중에서 100입중의 감소 정도가 가장 적었고, 수장과 수양구성 요소에 대한 변리계수는 상부이삭에 비하여 하부이삭에서 약 2배 정도 컸다.

• 통합자연과학논문집
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• 제1권3호
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• pp.234-246
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• 2008

Korean terminologies on stem structures in plant morphology, written incorrectly in many books, were analysed to propose accurately expressed terminologies. 35 books in areas such as general biology, plant biology, plant morphology, and biological dictionaries and glossaries were selected to analyse the accuracy of the terminologies for seed structures, e.g., shoot and shoot system, rhizome, apical dominance, anticlinal and periclinal divisions, and intercalary and lateral meristems. The definition and etymology of the terminologies were traced in 4 textbooks of plant anatomy and 2 dictionaries of biology and botany written in English. On the basis of the definition, etymology, and principles for terminology formation according to the International Organization for Standardization (ISO 704:2000), reasonably expressed Korean terminologies were proposed. All of the 8 terminologies examined in this study were included in the glossary of biological terminologies, published by the Korean Association of Biological Sciences in 2005, and designated as an editorial source for science and biology textbooks for middle and high schools by Ministry of Education in 2007. However, the only 1 of the 8 terminologies described in the glossary were consistent with the proposed expression in the present study. These inconsistencies indicated the need for a reassessment of this glossary of biological terminologies. The validity of the proposed Korean terminologies was tested in a questionnaire sent to 17 professors teaching plant morphology or/and taxonomy at universities. A mean of 91.9% of the total respondents agreed with the Korean expressions proposed in this study. The new, proposed terminologies would facilitate mutual understanding between teachers and students of plant biology.

• 농업과학연구
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• 제6권1호
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• pp.21-26
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• 1979

salvia의 생장억제(生長抑制)와 측지발달(側枝發達), 개화반응(開花反應) 등(等)에 관(關)한 dikegulac과 ancymidol의 효과(效果)를 비교(比較)하기 위하여 salvia 품종(品種) Bonfire를 공시(供試)하여 dikegulac 0.06%, 0.12%(엽면살포(葉面撒布))와 ancymidol 50 ppm, 100 ppm(엽면살포(葉面撒布)) 및 0.1 mg/pot, 0.5 mg/pot(토양주입(土壤注入))을 처리(處理)하였다. dikegulac 처리(處理)는 정아(頂芽)의 생장(生長)을 저해(沮害)하여 초장(草長)을 감소(減少)시키고 측지(側枝)의 발달(發達)을 유도(誘導)하여 개화경수(開花莖數)를 증가(增加)시켰으나 개화기(開花期)는 지연(遲延)시켰다. 또 잎의 엽록소(葉綠素) 함량(含量)을 증가(增加)시켜 관상가치(觀賞價値)를 증대(增大)시켰는데 특(特)히 chlorophyll a의 함량(含量)이 월등(越等)히 높아졌다. ancymidol 처리(處理)는 정아(頂芽)의 생장(生長)을 저해(沮害)하지 않고 초장(草長)을 감소(減少)시켜 개화기(開花期)에는 거의 영향(影響)하지 않았으나 개화경(開花莖) 증가(增加)에는 0.1 mg 토양주입구(土壤注入區)를 제(除)하고는 거의 효과(效果)가 없었다. 또 잎의 엽록소(葉綠素) 함량(含量)이 ancymidol 처리(處理)에 의해 현저(顯著)히 증가(增加)되었는데 dikegulac 처리구(處理區)와 마찬가지로 chlorophyll a의 함량(含量)이 현저(顯著)히 높아졌다. dikegulac은 salvia에서 매우 효과적(效果的)인 화학적(化學的) 적심제(摘心劑)로 사용(使用)될 수 있음을 알 수 있었다.

• 한국작물학회지
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• 제43권4호
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• pp.223-227
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• 1998

The objectives of this study were to find the sprouting condition and to establish the optimum production methods of plug seedlings in yacon (Polymnia sonchifolia Poepp. & Endl.). The sprouting ratio was greatest at $30\pm 1^{\circ}C$ at 20 days after planting. Crowns with single buds were more effective than those with two or more buds for sprouting, which might be due to the apical dominance. Planting the shoots separated from crown after sprouting in the single- and double-layer polyethylene-covered greenhouses reduced seedling period with 25% and 50%, respectively. Planting the shoots after sprouting was more effective than planting the crown buds. Double-layer polyethylene-covered green-house was good for plug seedling production than open field or single-layer polyethylene-covered greenhouse. The bed soils composed of clay loam : compost or sand : compost (1:l=v:v) were more effective to produce plug seedlings than only clay loam, sand or compost. Seedlings could be produced at 30 days after planting in our studies.

• The Korean Journal of Ecology
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• 제14권3호
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• pp.305-316
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• 1991

Growth hadit and demograph in a mature population of polygonatum and polygonatum humile in kanghwa island were studied for two growing seasons. Shoots of two species emerged early spring from the growing apices of the underdground rhizomes which had persisted for up to 1~5 year.after flowering, the ramets produced two rhizome buds at the shoot base. Bacause of the apical dominance in the rhizome system, a new rhizome was developed from only one bud, an actual bud,and the other latent buds were suppressed sothat remained dormant. The latent dud produced a new rhizome only when the actual dud was severed by the herbivores or by the physical obstacles. Therefore, the ramet number is not increased by the new rhizome from the latent bud. however, new ramets dould sometimes grow from latent buds which had been produced more than a year ago. Production of these ramets was main means increasing the ramet numbew and widening the potential zone of exploitation. Changes in size class of each ramet were noyiceable after a tear in small size-classes. Small ramets replaced themselves with larger-sized ramet, while large ramets with similar-sized or smallar-sized ramets. ramet numbers were average 0.82and 1.14 times of those fromthe previous year inp. involucratum and p. humile, though there was between-site variation. Almost all the ramets in the quadrats were alive during the growing season. when the entire rhizome systems were excavater next spring, there were many rhizomesegments without shoots, especially in p. involucratum. therefore, the drcrease of ramet number in p. involucratum in probably due to the climatic factors of winter.

• 한국잡초학회지
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• 제14권4호
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• pp.233-238
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• 1994

올방개 괴경(塊莖) 눈의 맹아특성(萌芽特性), 중경(中莖)과 뿌리위치(位置)의 변화(變化) 및 재생력(再生力) 등을 구명하여 방제약제개발(防除藥劑開發) 및 사용기술(使用技術)에 관한 기초자료(基礎資料)를 제공(提供)하기 위하여 1993년 실내(室內) 및 온실시험(溫室試驗)을 수행하여 다음과 같은 결과(結果)를 얻었다. 1. 대부분(大部分)의 괴경(塊莖)은 보통 1개의 눈만 맹아(萌芽)하고 앞의 눈이 제거(除去)되면 다음 눈이 순차적으로 맹아(萌芽)하는 정아우세성(頂芽優勢性)과 2개 이상의 중경(中莖)이 동시(同時)에 신장(伸長)하지 않는 경합관계(競合關係)가 인정(認定)되었다. 2. 제초제(除草劑)(pyrazosulfuron)처리(處理)에 의해서 정아(頂芽)는 전부 고사(枯死)하였으나 제1, 제2측아(側芽)는 각각 50%와 90%가 생존(生存)하였으며 제3측아(側芽)는 거의 맹아(萌芽)하지 않는 상태(狀態)로 생존(生存)하였다. 3. 토양(土壤) 10-15cm의 심층(深層)에 있는 괴경(塊莖)은 2-5cm 깊이의 표층(表層)에 있는 괴경(塊莖)에 비하여 1주일(週日) 늦게 출현(出現)하였고 출현율(出現率)도 35% 정도 낮았다. 4. 심토(深土)에서 발생(發生)하는 올방개일수록 중경(中莖)과 근부위치(根部位置)가 깊어지므로 발생(發生)깊이에 따라 약제반응(藥劑j反應)이 달라질 수 있었다. 5. 토양(土壤) 10cm와 15cm 깊이의 심층(深層)에서 발생(發生)할 경우(境遇) 중경신장(中莖伸長)이 정지(停止)되어 출현(出現)하지 못한 괴경(塊莖)의 비율(比率)이 각각 25%와 30%로서 심층(深層) 경(莖)의 출현율(出現率)이 낮았다. 6. 식물체(植物體)에서 늦게 떼어낸 괴경(塊莖)일수록 재생(再生)이 늦었으나 초장(草長) 20cm(줄기 6-9개)일 때 떼어낸 괴경(塊莖)일지라도 약 2주후(週後)에는 모두 재생(再生)하였다.

• Journal of Plant Biotechnology
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• 제5권4호
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• pp.215-219
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• 2003

Optimal shoot regeneration and transformation conditions of root type chicory (Cichorium intybus L. var. sativus cv Cesare) were studied. Leaf explants were co-cultured with Agrobacterium tumefaciens, which contained NPTII as a selectable marker and a rice homeotic gene, OsMADS1, that encodes a MADS-domain-containing transcription factor. After one day of co-cultivation, explants were transferred to selection media consisting of MS basal medium supplemented with 0.5 mg/L BAP, 0.1 mg/L IAA, 70 mg/L kanamycin, and 250 mg/L cefotaxime. PCR and Southern blot analyses revealed stable integration of the OsMADS1 gene in the chicory genome. Four-teen original transgenic plants ($T_o$ plants) were acclimatized in the greenhouse and examined for their morphological characters. Most of the transgenic plants showed altered morphologies, such as short, bushy, and early-flowering phenotypes with reduced apical dominance. Additionally, half of the transgenic plants exhibited altered leaf shapes, and 4 out of 14 plants were sterile. These phenotypes were inherited by the next generation. Northern blot analysis confirmed expression of the OsMADS1 gene in both floral and vegetative organs.

• 한국환경생태학회지
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• 제10권1호
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• pp.160-168
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• 1996

오대산 국립공원의 두로봉, 상왕봉 지구를 중심으로 분포하고 있는 천연림의 생육현황과 구조를 파악하고자, 이 지역에 19개의 방형구(10*10m)를 설치하여 식생을 조사하였다. 고산지대에 생육중인 주목과 분비나무를 대상으로 생육현황표를 이용하여 잎의 변색, 낙엽율, 줄기, 신초와 소지, 정아우세, 수세 등의 항목을 조사하였다. Cluster 분석한 결과 두 개의 군집(주목군지보가 신갈나무-사스래나무군집)으로 분류되었다. 수종간의 상관관계에서는 주목과 미역줄나무, 마가목; 분비나무와 신갈나무; 호랑버들과 부게꽃나무; 신갈나무와 참빗살나무 등의 수종들간에는 높은 저으이 상관이 인정되었고, 주목과 분비나무, 신갈나무 및 사스래나무; 분비나무와 미역줄나무 등의 수종들간에는 높은 부의 상관이 인정되었다. 조사대상지의 종다양도(H')는 1.2499~0.9608로 나타났다. 분비나무의 생육현황조사의 점수평균은 6.1점이며, 고사목의 비율이 10.9%였다. 주목의 생육현황조사의 점수평균은 17.3점이었고, 피해유형은 정단부를 비롯한 가지의 고사, 줄기의 동공, 줄기가 구부러지는 것 등의 세 가지였다.

• Molecules and Cells
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• 제27권2호
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• pp.183-190
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• 2009

The plasma membrane-localized BRASSINOSTEROID-INSENSITIVE1 (BRI1) and BRI1-ASSOCIATED KINASE1 (BAK1) are a well-known receptor pair involved in brassinosteroids (BR) signaling in Arabidposis. The formation of a receptor complex in response to BRs and the subsequent activation of cytoplasmic domain kinase activity share mechanistic characteristics with animal receptor kinases. Here, we demonstrate that BRI1 and BAK1 are BR-dependently phosphorylated, and that phosphorylated forms of the two proteins persist for different lengths of time. Mutations of either protein abolished phosphorylation of the counterpart protein, implying transphosphorylation of the receptor kinases. To investigate the specific amino acids critical for formation of the receptor complex and activation of BAK1 kinase activity, we expressed several versions of BAK1 in yeast and plants. L32E and L46E substitutions resulted in a loss of binding of BAK1 to BRI1, and threonine T455 was essential for the kinase activity of BAK1 in yeast. Transgenic bri1 mutant plants overexpressing BAK1(L46E) displayed reduced apical dominance and seed development. In addition, transgenic wild type plants overexpressing BAK1(T455A) lost the phosphorylation activity normally exhibited in response to BL, leading to semi-dwarfism. These results suggest that BAK1 is a critical component regulating the duration of BR efficacy, even though it cannot directly bind BRs in plants.