• Title/Summary/Keyword: Root primordia

Search Result 21, Processing Time 0.025 seconds

Studies on Rooting of Taxus cuspidata Cuttings by Electric Treatment (전기처리에 의한 주목의 삽목발근에 관한 연구)

  • 정진철;최정호;장규관
    • Journal of the Korean Institute of Landscape Architecture
    • /
    • v.22 no.2
    • /
    • pp.123-132
    • /
    • 1994
  • Tow-year-old Taxus cuspidata shoot cuttings were treated with various electrical impacts of cathode on their base and anode on their apex by normal and reverse source. The cuttings were previously treated with 200ppm IBA for 12 hours and the rooting percentage, the length, and the weight of roots were checked. The auxin contents of cuttings were also examined by high-performance liquid chromatography. The results obtained on this study are as follows; 1. Normal treatment, cathode into the base and anode into apex, seemed to accelerate rooting while reverse treatment showed less effective than normal treatment on rooting, but both treatments were more effective than control. 2. The impact of electrical treatment at 30mV for 30min has a remarkable effect on the percentage rooting, the length, and the weight of roots. 3. Root primordia were formed at the basipetal end of cuttings where the end of primary pith ray meets the cambium in control treatment and formed at the basal part of cuttings irregularly in electrical treatment. 4. High-performance liquid chromatography showed electrical treatment was more effective on auxin accumulation than control, and 30mV-30min was the most effective on auxin accumulation.

  • PDF

Relationship between cotyledon Number and Vascular System in Carrot Seedling (당근 유식물체에서 자엽수와 유관속계의 관련성)

  • 김경식
    • Korean Journal of Plant Resources
    • /
    • v.11 no.1
    • /
    • pp.30-39
    • /
    • 1998
  • Carrot seedling emgryos showing variations in cotyledon number were selected and anatomical comparisons of the embryo vascular systems were performed between the variants and normal two cotyledonary (5) embryos from 800 seedings germinated . Externally, all of the four and six cotyledonary embryos had two cotyledonary petioles. Each of the cotyledonary petioles divided into two or three on the upper part fo the petiole which result in four and six cotyledons, respectively. However, the embryos had three different cotyledonary petioles in the three cotyledonary embryos. On the basis of the pattern of vascular system, the four and six cotyledonary embryos had the same basic vascular system as fnormal two cotyledonary embryos, Therefore the cotyledon number abnormality could result from the branching split of the abnormally thickened upper part of the cotyledonary petiole. However, the three cotyledonaryembryos had a different vascular system from the normla two cotyledonary embryos. They could be regarded as different varieties form the two cotyledon embryos. All embryos observed had short cylindrical plumule sheath which formed by the fusion of the cotyledon bases. The presence of plumule sheath strontgly implied that the initiation of the cotyledons was not from the two localized primordia but from the circular proimordiu formed at the blobular stageof embryo, and it is not consistent with current views of cotyledon initiation. On the formation of the primary vascular system of carrot seedlings, it is suggested that the primary vascular system of the plumule was formed independently from that of the root-hypocotyle-cotyledon system.

  • PDF

Temporal and Spatial Downregulation of Arabidopsis MET1 Activity Results in Global DNA Hypomethylation and Developmental Defects

  • Kim, Minhee;Ohr, Hyonhwa;Lee, Jee Woong;Hyun, Youbong;Fischer, Robert L.;Choi, Yeonhee
    • Molecules and Cells
    • /
    • v.26 no.6
    • /
    • pp.611-615
    • /
    • 2008
  • DNA methylation is an epigenetic mechanism for gene silencing. In Arabidopsis, MET1 is the primary DNA methyltransferase that maintains CG DNA methylation. Plants having an overall reduction of MET1 activity, caused by a met1 mutation or a constitutively expressed MET1 antisense gene, display genome hypomethylation, inappropriate gene and transposon transcription, and developmental abnormalities. However, the effect of a transient reduction in MET1 activity caused by inhibiting MET1 expression in a restricted set of cells is not known. For this reason, we generated transgenic plants with a MET1 antisense gene fused to the DEMETER (DME) promoter (DME:MET1 a/s). Here we show that DME is expressed in leaf primordia, lateral root primoridia, in the region distal to the primary root apical meristem, which are regions that include proliferating cells. Endogenous MET1 expression was normal in organs where the DME:MET1 a/s was not expressed. Although DME promoter is active only in a small set of cells, these plants displayed global developmental abnormalities. Moreover, centromeric repeats were hypomethylated. The developmental defects were accumulated by the generations. Thus, not maintaining CG methylation in a small population of proliferating cells flanking the meristems causes global developmental and epigenetic abnormalities that cannot be rescued by restoring MET1 activity. These results suggest that during plant development there is little or no short-term molecular memory for reestablishing certain patterns of CG methylation that are maintained by MET1. Thus, continuous MET1 activity in dividing cells is essential for proper patterns of CG DNA methylation and development.

Regulation of Leaf Polarity during Leaf Development (잎의 발생과정에 있어서의 극성제어)

  • Cho, Kiu-Hyung;Jun, Sang-Eun;Tsukaya , Hirokazu;Kim, Gyung-Tae
    • Korean Journal of Plant Taxonomy
    • /
    • v.38 no.1
    • /
    • pp.51-61
    • /
    • 2008
  • Leaves are indeterminate organs and possess a lot of genes which is involved in establishing leaf polarities. These polarities are regulated relatively early during leaf development and defined relative to the factors intrinsic to the primordia and interactions with the shoot apical meristem (SAM). Recently, several genes that control the polarity of lateral organs have been identified. Our genetic study of deformed root and leaf1 (drl1) mutant, which produces narrow, filament‐like leaves and defective meristems, revealed that DRL1 is involved in the regulation of SAM activity and leaf polarity. The DRL1 gene was found to encode a novel protein showing homology to Elongator‐associate protein (EAP) of yeast KTI12. The amino acid sequence of DRL1 is universally conserved in prokaryotes and eukaryotes. DRL1 and the plant DRL1 homologs clearly formed a monophyletic clade, suggesting the evolutionary conservation of DRL1 homologs was maintained in the genomes of all land plants.

Shoot Proliferation and Plant Regeneration from Suspension-Cultured Cells of Dianthus gratianopol (패랭이꽃속 Dianthus gratianopol의 현탁배양세포로부터 Shoot 증식과 식물체 재분화)

  • Kim Joon-Chul
    • Journal of Plant Biotechnology
    • /
    • v.32 no.4
    • /
    • pp.301-306
    • /
    • 2005
  • Conditions for efficient organogenesis and plant regeneration from Dianthus gratianopol suspension cultured cells were established. Shoot-forming calli of glossy surface, pale green and knobby type were selected from leaf explant-derived calli and were suspension-subcultured every week in CP liquid medium with 1.0 mg/L 2,4-D and 0.5 mg/L BAP. Combinations of 1.0 mg/L 2,4-D and 0.5 mg/L BAP, and 1.5 mg/L 2,4-D and 0.5 mg/L BAP were effective for the induction of regenerative callus from the suspension cultured cell clusters. Multiple shoot primordia were initiated from the green spots of these regenerative callus and formed shoots on MS medium with 1.0 mg/L TDZ and 0.5 mg/L PAA. Shoot regeneration frequency (calli regenerating at least one shoot) was about 87%. For plant regeneration, proliferated shoots were excised and transferred to MS medium with 0.1 mg/L NAA for root initiation after 9 weeks of culture. The regenerants were potted in soil and formed the flowering buds and petals. Also, adventitious shoots were formed from the excised green shoot primordia of regenerative callus and these shoots proliferated successfully and regenerated to whole plants.

Study on Practical Micropropagation of Juiube Cultivars through Axillary Bud Culture (액아배양(腋芽培養)에 의한 신품종(新品種) 대추나무의 실용적(實用的)인 대량증식(大量增殖)에 관(關)한 연구(硏究))

  • Kim, Deok Sik;Lee, Sei Pyo
    • Journal of Korean Society of Forest Science
    • /
    • v.77 no.4
    • /
    • pp.445-452
    • /
    • 1988
  • This study was conducted to establish practical micropropagation of jujube cultivars ('Geumsumg', 'Bokjo') by axillary bud culture. The results are summerized as follows : 1. Addition of activated charcoal to half-strength Murashige and Skoog(MS) medium supplemented with 0.5mg/l benzylaminopurine(BAP) enhanced shoot and root growth. At 500mg/l activated charcoal level 'Geumsung' showed best result, and shoot length and the number of multiple shoot were 6.4cm and 10.0, respectively. At 1,000mg/l activated charcoal level 'Bokjo showed best result, and shoot length and the number of multiple shoot were 7.5cm and 12.4, respectively. 2. As indole-3-butyric acid(IBA) concentration increased, rooting and callus growth of microshoot were enhanced. The optimum IBA concentration for shoot elongation and multiplication was 1.0mg/l. 3. Growth responses of shoot-tip and axillary bud segments between two jujube cultivars were different. 'Geumsung' showed that axillary bud explants were about twice better than shoot-tip explants for shoot multiplication, but 'Bokjo' showed that shoot-tip explants mere better than axillary bud explants for shoot elongation and multiplication. 4. In acclimatization processes of plantlets produced in vitro, the survival of plantlets with only root primordia in soil medium was better than that of plantlets with several routs resulting in 97.8%. 5. In cutting of in vitro-derived microshoot, paclobutrazol was more effective than IBA, naphth-aleneacetic acid(NAA) and $Rooton^{(R)}$ in rooting and root growth.

  • PDF

Morphological Characteristics of Growth of Rice and Barnyardgrass under Various Cropping Patterns - II. Difference in Anatomical Characteristics (재배양식(栽培樣式)에 따른 벼와 피의 생장(生長) 및 해부형택학적(解剖形態學的) 차이(差異) - II. 재배양식(栽培樣式)에 따른 벼와 피간(間)의 해부학적(解剖學的) 차이(差異))

  • Chon, S.U.;Guh, J.O.;Park, S.J.
    • Korean Journal of Weed Science
    • /
    • v.14 no.2
    • /
    • pp.128-143
    • /
    • 1994
  • At 5 DAS/T, leaf primordia of rice stems that were grown under dry condition in transverse sections were strongly stained while those under water condition had many aerenchyma cells well developed. On the other hand, leaf primordia and large air spaces in stem of transplanted rice were well developed. Rice in leaf anatomy had small and fine epidermal cells, chlorophyllous mesophylls, and bulliform cells but had no chlorophyllous vascular bundle sheath cells, while barnyardgrass leaf had large, rough and irregularly arranged epidermal cells, chlorophyllous vascular bundle sheath cells, and non-bulliform cells but had no chlorophyllous mesophylls. Epidermal cells of transplanted rice, however, were well developed, differentiated and sclerified. Cross sections of rice root under dry condition showed cell contents, regularly arranged cells, non-intercellular spaces and non-aerenchyma while under water condition had well-developed intercellular spaces, aerenchyma cells, small and densely arranged epidermis, sclerified exodermis and sclerenchyma cells. But root anatomy of transplanted rice consisted of finely, regularly arranged epidermis, well-developed intercellular spaces and nucleous cells.

  • PDF

Morphological Characteristics of Growth of Rice and Barnyardgrass under Various Cropping Patterns - V. Difference in Morphological and Anatomical Response to Thiobencarb (재배양식(栽培樣式)에 따른 벼와 피의 생장(生長) 및 해부형태학적(解剖形態學的) 차이(差異) - V. 재배양식(栽培樣式)에 따른 제초제(除草劑) Thiobencarb에 대(對)한 벼와 피간(間)의 해부형태학적(解剖形態學的) 반응(反應) 차이(差異))

  • Chon, S.U.;Guh, J.O.;Kwon, S.L.
    • Korean Journal of Weed Science
    • /
    • v.14 no.3
    • /
    • pp.212-222
    • /
    • 1994
  • Thiobencarb retarded the growth of new leaves in only barnyardgrass under dry condition while under water condition the shoot growth of broadcast rice, and both shoot and root growth of barnyardgrass was considerably inhibited. Root elongation of rice and barnyardgrass was severely inhibited only under water condition, while that of transplanted rice was slightly inhibited. Inhibition of shoot and root growth in broadcast, drilled rice and barnyardgrass under water condition was much higher than that under dry condition, whereas the inhibition was less in transplanted rice than direct seeded rice. Microscopically, thiobencarb severely inhibited shoot growth and development of barnyardgrass by inducing tubular-like leaves. The cells of the shoot apices of treated barnyardgrass seedling under dry condition was vacuolated and irregularly arranged. Under water condition, leaf primordia of broadcast rice was constricted, barnyardgrass showed tubular-like leaves, inhibited apices elongation and vacuolated cells(visually lack cytoplasm).

  • PDF

Effect of BA Concentrations and Culture Methods on in Vitro Plant Multiplication from Shoot-Tip Culture of Wasabia japonica (고추냉이 정단배양에 있어서 BA 농도 및 배양방법에 따른 기내증식 효과)

  • Park, Yun-Young;Cho, Moon-Soo;Lee, Young-Deuk;Chung, Jong-Bae;Park, Shin;Jeong, Byeong-Ryong;Park, Sang-Gyu
    • Journal of Plant Biotechnology
    • /
    • v.34 no.1
    • /
    • pp.1-6
    • /
    • 2007
  • Effect of BA concentrations and culture methods on in vitro plant multiplication from shoot-tip cultures of Wasabia japonica was studied. Shoot-tips with leaf primordia and apical meristem were cultured on MS basal medium for all the experiments. Liquid medium for 2 weeks followed by semi-solid medium for 4 weeks containing 1.0 mg/L BA was the best to number of shoots (22.8) and shoot length (3.5 cm). Shoots proliferated could be divided into ca. 5 to 11 of cultures for the multiplication of plantlets. Divided plantlets showed root formation (90%) well onto MS basal medium without growth regulators like IBA and NAA. After rooting, all the plantlets transferred into the pots containing composed soil (bio-media Co., peatmoss $8{\sim}10%$, coir dust $66{\sim}70%$, zeolite $13{\sim}17%$, vermiculite $3{\sim}7%$, perlite $2{\sim}4%$) and grown well into whole plants with multiple shoots.

STUDIES ON THE TISSUE CULTURE OF PANAX GINSENG

  • Harn C
    • Proceedings of the Ginseng society Conference
    • /
    • 1974.09a
    • /
    • pp.9-22
    • /
    • 1974
  • Unlike the tissue culture in animals and human being, in higher plants various parts of the plant are cultured for varied purposes, and they are named variously depending on which parts are used as explants or what purposes they are cultured for. Followings are some of the names of culture used frequently: organ culture, tissue culture, callus culture, single cell culture, meristem culture, mericlone culture, ovary culture, ovule culture, embryo culture, endosperm culture, anther culture, pollen culture, protoplast culture, etc.. As the names of the culture indicate, in some kinds of culture the explants used for culture are actually not tissues, but organs, single cells, or protoplasts. It seems, however, convenient to call all of the above-mentioned cultures grossly as tissue culture. Several kinds of tissue culture were attempted using Panax ginseng as material and some of the results were summarized below. 1. Callus culture After dormancy of the sed was broken, whole embryo or parts (hypocotyl, cotyledon and epicotyl) of partly grown embryo were cultured in the media supplemented with growth regulators. Rapid swelling occurred in a few weeks, but most of the swelling was observed only in the basal part of epicotyl, changes in the other parts of embryo appearing in much later stages. The swelling or increase in size, however, was resulted not from the divisions of cells, but from the mere expansion of cell. Real calli were formed about two months after inoculation of explants. Callus tissues developed from cortex, pith, and vascular bundle in the cases of hypo- and epicotyl, from mesophyl tissue in the case of cotyledon. Shoots developed more easily from cotyledons regardless of whether they are detached from or attached to the embryo proper. 2. Culture in the Knudson C medium When cotyledons, detached from or attached to the embryo proper, were cultured in the growth regulator-free Knudson C medium comprision only several kinds of mineral compounds and sucrose, shoot primordium or callus developed profusely and finally plantlets were produced directly from shoot primordium or indirectly through callus. In this medium epidermal cells as well as mesophyl cells of the cotyledon became meristematic and divided, changing into multinucleate cells or multicellular bodies, developing eventually into either shoot primordia or calli. 3. Anther culture Anthers were cultured in the media supplemented with various growth regulators applied singly or in combinations. Callus was formed mostly in the connective tissue of anther. Cells of anther wall layers changed in appearance, but no division occurred. Microspores of all stages in development were not changed, ruling out the possibility that microspore-originated callus might be formed. 4. Isolation of protoplast Protoplasts were isolated from young root, leaf, and epicotyl, using 0.7M D-mannitols as osmoticum and using macerozyme and cellulase respectively for maceration and digestion of the cell wall. Production in large number of naked intact protoplast was rather difficult as compared with other plant species. Fusion of protoplasts occurred infrequently mainly due to the fewer number of naked protoplasts in the solution.

  • PDF