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1.
Shinjiro Ogita Hamako Sasamoto Edward C. Yeung Trevor A. Thorpe 《In vitro cellular & developmental biology. Plant》2001,37(2):268-273
Summary Embryogenic tissues of sugi (Cryptomeria japonica) were induced on a modified Campbell and Durzan (CD) medium containing 1 μM 2,4-dichlorophenoxyacetic acid (2,4-D) and 600 mg l−1 glutamine, and subcultured in the medium of the same composition for over 1 yr. This resulted in a mixed culture of embryogenic
and non-embryogenic cells. When embryogenic cells were isolated and cultured independently, their capacity to form embryogenic
aggregates was lost. Thus, the non-embryogenic cells present within a mixed culture system were essential to the formation
of embryogenic aggregates. When embryogenic tissues were isolated and cultured independently on a high glutamine-containing
(2400 mg l−1) medium, dry weights and endogenous levels of glutamine increased, and the tissue could generate a large number of embryogenic
aggregates. Amino acid analysis of embryogenic and non-embryogenic cells from the maintenance culture indicated a higher level
of glutamine was present in the latter. The high endogenous level of glutamine in the non-embryogenic portion of mixed cell
masses may be the supplier of glutamine for maintaining the embryogenic property of the tissues. 相似文献
2.
Summary First divisions of embryogenic cells were studied in leaves of plantlets of aCichorium hybrid (C. intybus L. ×C. endivia L.) cultured in vitro in a liquid agitated medium, at 35 °C in the dark. Stages of reactivation of competent cells were characterized by increase of nucleus and nucleolus diameter, migration of the nucleus in the centre of the cell and thickening of the cell wall. The first division of reactivated embryogenic cells was symmetrical and anticlinal in regard to the xylem vessels orientation. Embryogenic structures consisted in I-type tetrads or in rows of 4–8 cells. Then the divisions occurred in thickness at one end, without polarization or formation of a suspensor-like structure.Abbreviations EC
embryogenic cell
- ES
embryogenic structure 相似文献
3.
Summary Primary embryogenic callus ofDrosera rotundifolia and long-term cultured embryogenic callus ofZea mays possess a conspicuous extracellular matrix (ECM) around and between embryogenic cells. The structural arrangement of ECM depends on the developmental stage of the embryogenic cells. Single embryoid cells were covered with, and connected by net-like material. However, surface cells of young globular embryoids were covered with a coherent layer of ECM which forms bridges with net-like material between the cells which was gradually reduced to coarse strands. When protodermis was formed on the surface of globular embryoids, the ECM disappeared completely. The ECM network was never observed on the surface of heart- and torpedo-shaped embryoids. Safranine (especially 0.1%) stabilized the structure of ECM. Digestion with pronase E and proteinase K indicated that the ECM contains proteinaceous components. Similar developmental patterns of ECM were observed in dicotyledonous and monocotyledonous examples. The ECM represents a stable morphological structure even during long-term embryogenic culture in maize.Abbreviations 2,4-D
2,4-dichlorophenoxyacetic acid
- Dicamba
3,6-dichloro-o-anisic acid
- ECM
extracellular matrix
- KIN
kinetin
- SEM
scanning electron microscopy
- TEM
transmission electron microscopy 相似文献
4.
Samaj J Salaj T Matúsová R Salaj J Takác T Samajová O Volkmann D 《Plant cell reports》2008,27(2):221-229
Arabinogalactan proteins (AGPs) are important proteoglycans regulating somatic embryogenesis in diverse plant species. Embryogenic
cells of somatic embryos are covered by special extracellular cell wall layer called extracellular surface matrix network
(ECMSN) at their early developmental stages. Here we show that highly embryogenic cell line AC78 of hybrid fir (Abies alba × Abies cephalonica) differs from very low-embryogenic cell line AC77 in the abundance, subcellular localization and deposition of subset of
secreted AGPs. A specific AGP epitope containing Gal residues and reacting to Gal4 antibody is secreted and deposited into
ECMSN, which covers the surface of the embryogenic cells showing high embryogenic and regeneration capacity in the cell line
AC78. On the other hand, this Gal4 AGP epitope was not secreted and/or found on the surface of meristematic cells showing
low embryogenic and regeneration capacity in the cell line AC77, as well as on the surface of non-embryogenic suspensor cells
and callus cells in both cell lines AC77 and AC78. As a positive control, we have used another AGP epitope LM2 (containing
glucuronic acid) showing no significant differences in these two Abies hybrid lines. This study defines specific AGPs containing β-(1→6)-galactotetraosyl group as a first molecular component of
ECMSN covering embryogenic cells in gymnosperms.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
5.
Sacco C. de Vries Hilbert Booij Peter Meyerink Gert Huisman H. Dayton Wilde Terry L. Thomas Ab van Kammen 《Planta》1988,176(2):196-204
Embryogenic suspension cultures of domesticated carrot (Daucus carota L.) are characterized by the presence of proembryogenic masses (PEMs) from which somatic embryos develop under conditions of low cell density in the absence of phytohormones. A culture system, referred to as starting cultures, was developed that allowed analysis of the emergence of PEMs in newly initiated hypocotyl-derived suspension cultures. Embryogenic potential, reflected by the number of FEMs present, slowly increased in starting cultures over a period of six weeks. Addition of excreted, high-molecular-weight, heat-labile cell factors from an established embryogenic culture considerably accelerated the acquisition of embryogenic potential in starting cultures. Analysis of [35S]methionine-labeled proteins excreted into the medium revealed distinct changes concomitant with the acquisition of embryogenic potential in these cultures. Analysis of the pattern of gene expression by in-vitro translation of total cellular mRNA from starting cultures with different embryogenic potential and subsequent separation of the [35S]methionine-labeled products by two-dimensional polyacrylamide gel electrophoresis demonstrated a small number of abundant in-vitro-translation products to be present in somatic embryos and in embryogenic cells but absent in nonembryogenic cells. Several other in-vitro-translation products were present in explants, non-embryogenic and embryogenic cells but were absent in somatic embryos. Hybridization of an embryoregulated complementary-DNA sequence, Dc3, to RNA extracted from starting cultures showed that the corresponding gene is expressed in somatic embryos and PEMs but not in non-embryogenic cells.Abbreviations 2,4-D
2,4-dichlorophenoxyacetic acid
- cDNA
complementary DNA
- PAGE
polyacrylamide gel electrophoresis
- PEM
proembryogenic mass 相似文献
6.
Summary This paper investigates maintenance and proliferation of somatic embryogenesis systems for Ulmus minor and U. glabra. Proliferation occurred with subculture of embryogenic calluses. The calluses were mainly formed by friable nodules composed
of meristematic cells organized into proembryogenic cell masses (PEMs) and thin-walled vacuolated parenchymatic cells. Cotyledonary
embryos, with procambial strands and differentiation of their vascular tissues as well as visible root meristems, were identifiable
after 18d of culture on a proliferation medium with 0.44 μM benzyladenine (BA). The shoot meristem was only occasionally well developed. Somatic embryo multiplication from elm embryogenic
calluses is a clearly asynchronic system, and PEMs as well as embryos at all stages of development are observed simultaneously
at the end of subculture period. Factors affecting the proliferation of elm embryogenic callus, such as culture medium, carbon
source and genotype, were studied. Basal medium (MS) or medium supplemented with 0.44 μM BA produced the highest number of somatic embryos. Somatic embryo production was higher with sucrose or glucose than with
maltose, and significant differences were also found among the four embryogenic lines tested. The use of liquid medium with
filter paper support is an essential step for the survival of isolated somatic embryos during the germination stage. The addition
of 0.22 μM BA′ to liquid MS medium was the best treatment for germination and plantlet conversion of elm somatic embryos. 相似文献
7.
Francisco Quiroz-Figueroa Marcela Mndez-Zeel Felipe Snchez-Teyer Rafael Rojas-Herrera Victor M. Loyola-Vargas 《Journal of plant physiology》2002,159(11):1267
Somatic embryogenesis (SE) is a very useful system for studying the differentiation process in plants and involves gene regulation at several levels. During SE induction in Coffea arabica cv. Catura Rojo two types of cell clusters, embryogenic (EC) and non-embryogenic (NEC), were observed. The goal of this work was to compare the most relevant characteristics between EC and NEC for a better understanding of the mechanism driving SE. Morphohistological observations indicated a correlation between the morphological features of clusters and their embryogenic competence. On the other hand, no variation at the DNA level, studied by AFLP, were found to explain the disparity in embryogenic competence of clusters, but gene expression, observed by RNA differential display, and SDS-PAGE showed differences that can explain that disparity. Our results lead us to propose that differential gene expression can modulate the embryogenic capacity of coffee cells and that the number of genes turned off in somatic cells to allow for the change from a somatic to an embryogenic state, is higher than those genes that are turned on. 相似文献
8.
We identified and isolated a monoclonal antibody (MAb 3G2) raised against extracellular proteins from microcluster cells of
orchard grass (Dactylis glomerata L.) embryogenic suspension culture. MAb 3G2 recognized with high specificity an antigen ionically bound within the primary
cell wall and in the culture medium of microcluster cells. Two-dimensional polyacrylamide gel analysis and blotting of proteins
on PVDF membrane showed that MAb 3G2 detected a single polypeptide of apparent molecular mass of 48 kDa and an isoelectric
point (pI) of 5.2, designated EP48. A transient expression during somatic embryogenesis was observed for EP48. Indirect immunofluorescence
showed that this protein highly accumulated in the cell walls of some single cells, microclusters and partly in proembryogenic
masses (PEMs), but not in globular embryos of the embryogenic cell line and microclusters from the non-embryogenic cell line.
Signal intensity varied between individual cells of the same population and in successive stages of somatic embryo development.
Screening of several D. glomerata L. embryogenic and non-embryogenic cell lines with MAb 3G2 indicated the presence of ECP48 in only embryogenic suspension
cultures at early stages of embryo development long before morphological changes have taken place and thus it could serve
as an early marker for embryogenic potential in D. glomerata L. suspension cultures. 相似文献
9.
10.
Induction of somatic embryogenesis and adventitious shoots from immature leaves of cassava 总被引:4,自引:0,他引:4
Direct somatic embryogenesis was successfully achieved from immature leaves of cassava (Manihot esculenta Crantz) cultured on induction medium containing 2,4-dichlorophenoxyacetic acid or naphthaleneacetic acid. Changing the duration of induction or changing plant growth regulators resulted in differences in regeneration of somatic embryos or adventitious shoots. The results showed that auxin was a key factor for inducing embryogenic cells. The embryogenic cells were mainly induced within 4–12 days. Only if the embryogenic cells were induced, the auxin enhanced formation of somatic embryo whereas 6-benzylaminopurine stimulated development of adventitious shoots. Histological examinations supported the conclusion. 相似文献
11.
M. M. H. Kristensen J. I. Find F. Floto J. D. MØller J. V. NØrgaard P. Krogstrup 《Protoplasma》1994,182(1-2):65-70
Summary The development of somatic embryos in an embryogenic suspension culture ofPicea sitchensis was followed every day for two weeks after thawing from liquid nitrogen (LN2). Only a few cells, primarily located at the periphery of the embryonic region of the embryos, survived cryopreservation in LN2. Surviving cells were classified into two groups: embryogenic cells (EC) and non-embryogenic cells (NEC), based on their morphology and embryogenic competence. The dense cytoplasmic EC underwent organized growth and differentiation with first divisions occurring after 24 h, and embryo formation 6–8 days after thawing from LN2. No evidence of asymmetrical divisions or free-nuclear stages was found during somatic embryo formation. NEC had less dense cytoplasm with numerous small vacuoles. One to five days after thawing the NEC became progressively more vacuolated and elongated. Histological examination revealed no mitotic activity in NEC, and six days after thawing NECs were seen as single cells or unorganized cell aggregates. Two weeks after thawing the appearance of the cryopreserved cultures was comparable to that of the untreated cultures.Abbreviations EC
embryogenic cells
- ECC
embryogenic cell clusters
- FDA
fluorescein diacetate
- GMA
glycol methacrylate
- LN2
liquid nitrogen (–196°C)
- NEC
non-embryogenic cells 相似文献
12.
Gorpenchenko TY Kiselev KV Bulgakov VP Tchernoded GK Bragina EA Khodakovskaya MV Koren OG Batygina TB Zhuravlev YN 《Planta》2006,223(3):457-467
Expression of the Agrobacterium rhizogenes rolC gene in Panax ginseng callus cells results in formation of tumors that are capable to form roots. The selection of non-root forming tumor clusters
yielded the embryogenic 2c3 callus line, which formed somatic embryos and shoots independently of external growth factors.
Although the 2c3 somatic embryos developed through a typical embryogenesis process, they terminated prematurely and repeatedly
formed adventitious shoot meristems and embryo-like structures. A part of the shoots and somatic embryos formed enlarged and
fasciated meristems. This is the first indication of the rolC gene embryogenic effect and, to our knowledge, the first indication that a single gene of non-plant origin can induce somatic
embryogenesis in plants. 相似文献
13.
O. M. -F. Zaghmout 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1994,89(5):577-582
A procedure for culturing protoplasts from slowly growing embryogenic calli of wheat was developed. The procedure was dependent on the ability to isolate large numbers of culturable protoplasts from slowly growing embryogenic callus. Approximately 68% of the isolated protoplasts divided, and 22% formed colonies; of the latter, 67% continued to proliferate. Plating efficiency was reduced when protoplasts were transformed by polythylene glycol, electroporation, and/or Agrobacterium. Intact cells were also directly transformed by electroporation. Direct electroporation of the Agrobacterium binary vector into intact cells resulted in a significant increase of GUS activity over the control. 相似文献
14.
Somatic embryogenesis and plant regeneration of turf-type bermudagrass: Effect of 6-benzyladenine in callus induction medium 总被引:17,自引:0,他引:17
In order to optimize tissue culture conditions for bermudagrass, an important warm-season turfgrass species, tissue culture
responses of young inflorescences of a hybrid bermudagrass cultivar `Tifgreen' (Cynodon dactylon×Cynodon transvaalensis) and a common bermudagrass cultivar `Savannah' (Cynodon dactylon) were investigated. When cultured on Murashige and Skoog medium with 4.52 to 13.57 μM (1–3 mg l-1) 2,4-D, young inflorescence segments yielded non-embryogenic calli which were unorganized and had loosely associated, long
tubular cells on the surface. However, inclusion of 6-benzyladenine (BA) in callus induction medium at a level of 0.044 μM
(0.01 mg l-1) induced formation of a compact, nodular embryogenic structure on approximately 20% of the calli. Calli with such a compact
embryogenic structure were highly regenerable. When young inflorescences smaller than 0.75 cm were cultured, the embryogenic
structure yielded green plantlets with regeneration rates of 79.5% and 83.3%, respectively for the two cultivars. All 96 plants
regenerated from calli induced in the BA-containing medium were green and morphologically normal. The embryogenic nature of
the compact structure was confirmed by scanning electron microscopy.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
15.
U. K. S. Shekhawat T. R. Ganapathi L. Srinivas V. A. Bapat T. S. Rathore 《Plant Cell, Tissue and Organ Culture》2008,92(3):261-271
An efficient method for Agrobacterium-mediated genetic transformation of embryogenic cell suspension cultures of Santalum album L. is described. Embryogenic cell suspension cultures derived from stem internode callus were transformed with Agrobacterium
tumefaciens harbouring pCAMBIA 1301 plant expression vector. Transformed colonies were selected on medium supplemented with hygromycin
(5 mg/l). Continuously growing transformed cell suspension cultures were initiated from these colonies. Expression of β-glucuronidase
in the suspension cultures was analysed by RT-PCR and GUS histochemical staining. GUS specific activity in the transformed
suspension cultures was quantified using a MUG-based fluorometric assay. Expression levels of up to 105,870 pmol 4-MU/min/mg
of total protein were noted in the transformed suspension cultures and 67,248 pmol 4-MU/min/mg of total protein in the spent
media. Stability of GUS expression over a period of 7 months was studied. Plantlets were regenerated from the transformed
embryogenic cells. Stable insertion of T-DNA into the host genome was confirmed by Southern blot analysis. This is the first
report showing stable high-level expression of a foreign protein using embryogenic cell suspension cultures in S. album.
U. K. S. Shekhawat and T. R. Ganapathi contributed equally to this work. 相似文献
16.
Summary The cell ultrastructure in three types of callus obtained from leaf explants ofAesculus hippocastanum L. has been studied. Remarkable differences have been shown between the cells of the forerunner E1 callus and those of the callus arising from it, according to the culture conditions.The peculiar characteristics of E1 are the scarcity of intercellular spaces and the occurrence of autophagic vacuoles in the cells.An embryogenic friable callus (E2) is formed in time when E1 is maintained on solid culture medium. The E2 cells show cytological features typical of a higher metabolic level and contain starch. Diffused middle lamella digestion leads to the detachment of small embryogenic cell aggregates consisting of vacuolated parenchymatous-like cells and small meristematic cells which may be regarded as embryoids initials.Shaking E1 in the same liquid medium and subsequent culture on solid medium lead to the differentiation of a non-embryogenic callus (NE), whose cells are very large and highly vacuolated, devoid of starch and with organelle-rich cytoplasm. The NE callus shows a high degree of growth, but does not attain embryogenic competence in time.Abbreviations
c
cell
-
cr
crystal
-
cw
cell wall
-
d
dictyosome
-
er
endoplasmic reticulum
-
m
mitochondrion
-
mb
microbody
-
n
nucleus
-
p
plastid
-
s
starch
-
v
vacuole 相似文献
17.
Q. C. Liu H. Zhai Y. Wang D. P. Zhang 《In vitro cellular & developmental biology. Plant》2001,37(5):564-567
Summary Using 15 Chinese and Japanese cultivars of sweetpotato, Ipomoea batatas (L.) Lam., we succeeded in developing an efficient plant regeneration system from embryogenic suspension cultures. The embryogenic
callus derived from shoot apices of the 15 cultivars was used to initiate embryogenic suspension cultures in Murashige and
Skoog (MS) medium containing 9.05 μM 2,4-dichlorophenoxyacetic acid (2,4-D). Rapidly proliferating and well-dispersed embryogenic suspension cultures were established.
Cell aggregates 0.7–1.1 mm in size from embryogenic suspension cultures were transferred to solid MS medium supplemented with
9.05 μM of 2,4-D and formed embryogenic callus with somatic embryos. The embryogenic callus with somatic embryos was further transferred
to MS medium supplemented with 3.78 μM of abscisic acid, resulting in the germination of somatic embryos. Within 20 wk after the initiation, the frequencies of
cell aggregates forming plantlets reached approximately 100% for the 15 tested cultivars. These plantlets, when transferred
to soil, showed 100% survival. No morphological variations were observed. 相似文献
18.
L. L. DeVerno P. J. Charest L. Bonen 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1994,88(6-7):727-732
outhern hybridization analysis using wheat mitochondrial gene-specific probes indicates that changes in mitochondrial genomic organization and the relative representation of certain genomic regions occur during in vitro somatic embryogenic cell culture ofLarix species. We observed differences in the mitochondrial (mt)DNA hybridization patterns between somatic embryogenic cell cultures and trees grown from seed forLarix leptolepis,L. decidua, and the reciprocal hybrids of these twoLarix species. This is the first study to describe the correlation of molecular changes in a gymnosperm mitochondrial genome with in vitro somatic embryogenic cell culture. Quantitative differences in mtDNA hybridization signals were also observed among a 4-year-old somatic embryogenic cell culture ofLarix ×eurolepis trees regenerated from this culture, and the seed source tree from which the somatic embryogenic cell cultures were initiated. 相似文献
19.
L. Q. Zhao S. X. Cui L. X. Zhang C. L. Zhang 《Plant Cell, Tissue and Organ Culture》2005,79(3):291-298
Adaptations to salt stress were studied in embryogenic cultures from two ecotypes of reed (Phragmites communisT.). In the 600 mM NaCl treatment, relative cell viability of dune reed embryogenic cultures from a desert region was 56% greater than the control, 198% greater than swamp reed embryogenic cultures. After treatment with different NaCl concentrations, their relative growth rates (RGRs), pyridine nucleotides, activities of antioxidant enzymes and plasma membrane H+-ATPase (EC 3.6.1.35) were determined. The results showed that NADPH content, NADPH/NADP+ ratio and the activity of plasma membrane H+-ATPase in dune reed embryogenic cultures were higher than those of the control in the present of 600 mM NaCl. The activities of peroxidase (POD, EC 1.11.1.7) and catalase (CAT, EC 1.11.1.6) increased more in dune reed embryogenic cultures than in swamp reed embryogenic cultures. Dune reed embryogenic cultures tolerated higher concentration of NaCl than swamp reed embryogenic cultures. Under high concentration of NaCl, the survival of dune reed embryogenic cultures might be due to reductive status maintenance and ions absorption regulation in the plant cells. This phenomenon would be a result of cross-adaptation in nature. 相似文献
20.
The inter-relationship between exogenous calcium (Ca2+) during cold pretreatment and cold-enhanced somatic embryogenesis was investigated using cell suspension cultures of Astragalus adsurgens Pall. Cell suspension was obtained from embryogenic callus and could be induced to form somatic embryos in the differentiation medium. Suspension cells, after cold-treatment at 8 °C for 2 to 3 wk, displayed an enhanced capacity for somatic embryogenesis as compared to those without cold pretreatment. Longer cold pretreatment (> 4 wk) resulted in the inhibition of somatic embryogenesis. The enhanced embryogenic response of cells to cold pretreatment was dependent on the Ca2+ level in the pretreatment medium. Ca2+ levels below 1 mM suppressed the cold-enhanced response. Addition of lanthanum into the pretreatment medium completely abolished the cold induced enhancement of somatic embryogenesis. These results suggest that embryogenic cells require a minimal concentration of Ca2+ during pretreatment for the expression of this cold-enhanced capacity for somatic embryogenesis in A.adsurgens and the influx of exogenous Ca2+ during pretreatment might also be involved. 相似文献