共查询到20条相似文献,搜索用时 15 毫秒
1.
P. Grappin C. Audeon M. -C. Chupeau M. -A. Grandbastien 《Molecular & general genetics : MGG》1996,252(4):386-397
A new transposable element of tobacco, Slide, was isolated from thetl mutant line, which shows somatic instability, after its transposition into a locus encoding nitrate reductase (NR). The Slide-124 element is 3733 bp long and its coding sequences show similarities with conserved domains of the transposases ofAc, Tam3 andhobo. Excision from the NR locus is detectable in somatic leaf tissues and Slide mobility is triggered by in vitro tissue culture. Slide excision events create footprints similar to those left byAc and Tam3. Tobacco lines derived from thetl mutant line seem characterized by unmethylated copies of a few members of the highly repetitive Slide family. Slide mobility was monitored in transient expression assays. In wild-type tobacco protoplasts, the complete Slide element, as well as a defective copy, is able to excise. The complete Slide element, but not the defective version, is able to excise in protoplasts of the heterologous species lettuce (Lactuca sativa). These results show that Slide carries the functions required for its own mobility, and represents the first autonomousAc-like element characterized inSolanaceae species. 相似文献
2.
Rosemary Carpenter Cathie Martin Enrico S. Coen 《Molecular & general genetics : MGG》1987,207(1):82-89
Summary In Antirrhinum majus the transposable element Tam3 has been described at two unlinked loci pallida and nivea, both of which are required for the production of anthocyanin pigment in flowers. In each case the element is inserted in the promoter region and gives a variegated phenotype. We show that the rate of Tam3 excision at both loci is greatly affected by temperature, being approximately 1000-fold higher at 15°C compared with 25°C. Tam3 is also controlled by an unlinked gene Stabiliser, which considerably reduces excision rate. We show that the high degree of sensitivity to temperature and Stabiliser is an intrinsic property of Tam3 which is not shared by an unrelated element, Tam1. The Tam3 insertion at nivea gives rise to a series of alleles which confer reduced pigmentation, novel spatial patterns and changed instability. These are probably a result of imprecise excision and rearrangements of the Tam3 element. 相似文献
3.
Summary Two stable derivatives of the highly unstable niv-53::Tam1 allele of Antirrhinum majus were analysed. In both derivatives the Tam1 element is integrated at the same site and in the same orientation as in the parental niv-53::Tam1 allele. In both cases the Tam1 element was found to carry a 5 bp deletion (CACTA) in one of its termini. This explains the excision deficiency of these two alleles of Tam1, niv-53::Tam1-46 and niv-53::Tam1-49. Niv-44::Tam2, another stable nivea mutation, carries the 5 kb element Tam2, which is not a derivative of Tam1 but possesses identical terminal inverted repeats. When the stable lines 46 and 49 were corssed with line 44, suprisingly, a high number of the flowers in the F1 displayed a variegated phenotype. Sequence analysis of two germinal revertants isolated from the heterozygote niv-53::Tam1-46/niv-44::Tam2 shows excision of the Tam2 element. This indicates that Tam2 is a defective element, which can be complemented by an active Tam1 element. However, the variegated F1 phenotype observed is not inherited monofactorially. Variegation is seen only at particular times of development of the F1 plants. These phenomena seem to involve both the Tam1 and Tam2 transposable elements. 相似文献
4.
V. M. Peschke R. L. Phillips 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1991,81(1):90-97
Summary Previous experiments have revealed that the maize transposable element Activator (Ac) may become active during tissue culture. The objective of the present study was to determine whether a second transposable element, Suppressor-mutator (Spm), could also be activated in tissue culture and detected in regenerated maize plants. Approximately 500 R1 progeny of 143 regenerated plants (derived from 49 embryo cell lines) were crossed as males onto an Spm-responsive tester stock. Spm activity was observed in two R1 progeny of a single regenerated plant. This plant had been regenerated from Type II (friable embryogenic) callus of an A188 × B73 genetic background after 8 months in culture; the absence of Spm activity in four other plants regenerated from this same callus demonstrates that Spm activity was not present before culturing. Approximately 20 Spm-homologous DNA sequences were detected in each of the inbreds used to initiate the tissue cultures; it is presumed that one of these became active to give rise to Spm activity. 相似文献
5.
M. Nakano Y. Hoshino M. Mii 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1996,92(2):170-172
Hypocotyl-derived protoplasts of Dianthus barbatus that had been pretreated with iodoacetamide were fused electrically with cell suspension culture-derived protoplasts of Gypsophila paniculata that could divide to form callus but could not regenerate shoots under the culture conditions used in this study. Electrofusion-derived calli which produced shoots were selected as putative somatic hybrids, and plantlets were subsequently regenerated from 2 of these selected calli. These plantlets, which in vitro produced flowers precociously, were identified as intergeneric somatic hybrids by nuclear ribosomal DNA analysis. Normal plants have not been established up to the present. 相似文献
6.
Summary Growth characteristics of tobacco protoplasts containing rolA linked to its own promoter, or the rolB, or rolC genes of Agrobacterium rhizogenes linked to the Cauliflower Mosaic Virus 35S RNA promoter were compared with those from untransformed plants. RolA protoplasts require auxin and cytokinin for callus formation. Protoplasts overexpressing rolB and C form callus in the absence of exogenously applied auxin and cytokinin, respectively. Long term callus growth requires auxin, but the requirement for cytokinin is not critical. Optimal transient expression of an auxin responsive promoter element occurred at lower external levels of auxin in rolB and rolC protoplasts compared with untransformed protoplasts. Addition of putrescine was required for auxin responsive transient gene expression in rolA protoplasts suggesting that polyamines, or their products affect gene expression in rolA plants.Abbreviations T-DNA
transferred DNA
- TL-DNA
left transferred DNA
- NAA
naphthalene acetic acid
- PEG
polyethylene glycol
- GUS
glucuronidase
- CaMV
cauliflower mosaic virus 相似文献
7.
Summary Plantlets were regenerated from protoplasts of in vitro shoot cultures and leaf-derived de novo shoots of the chrysanthemum Dendranthema zawadskii x D. grandiflora. Isolated protoplasts reformed cell walls and then began to divide within 24 hours of culture in streaky plate agarose lenses surrounded by liquid V-KM medium. Twenty one days after isolation, 1 mm diameter callus clumps were transferred to shoot regeneration medium. After a further 33 days leaves became visible. Elongated shoots were rooted on half strength hormone-free MS medium.Abbreviations BAP
6-benzylaminopurine
- IAA
3-indoleacetic acid
- MS
Murashige and Skoog (1962)
- NAA
1-naphthylacetic acid
- Pfr
Photon fluence rate
- V-KM
Binding and Nehls (1977) 相似文献
8.
R. L. Wright D. A. Somers R. L. McGraw 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1987,75(1):151-156
Summary Somatic hybrid plants were produced by fusion of birdsfoot trefoil (Lotus corniculatus) cv Leo and L. conimbricensis Willd. protoplasts. Birdsfoot trefoil etiolated hypocotyl protoplasts were inactivated with iodoacetate to inhibit cell division prior to fusion with L. conimbricensis suspension culture protoplasts. L. conimbricensis protoplasts divided to form callus which did not regenerate plants. Thus, plant regeneration from protoplast-derived callus was used to tentatively identify somatic hybrid cell lines. Plants regenerated from three cell lines exhibited additive combinations of parental isozymes of phosphoglucomutase, and L. conimbricensis-specific esterases indicating that they were somatic hybrids. The somatic chromosome number of one somatic hybrid was 36. The other somatic hybrid exhibited variable chromosome numbers ranging from 33 to 40. These observations approximate the expected combination of the birdsfoot trefoil (2n=4x=24) and L. conimbricensis (2n=2x=12) genomes. Somatic hybrid flowers were less yellow than birdsfoot trefoil flowers and had purple keel tips, a trait inherited from the white flowered L. conimbricensis. Somatic hybrids also had inflorescence structure that was intermediate to the parents. Fifteen somatic hybrid plants regenerated from the three callus lines were male sterile. Successul fertilization in backcrosses with birdsfoot trefoil pollen has not yet been obtained suggesting that the hybrids are also female sterile. This is the first example of somatic hybridization between these two sexually incompatible Lotus species.Formerly USDA-ARS, St. Paul, Minn, USA 相似文献
9.
Summary Protoplasts isolated enzymatically from precultured cotyledonary leaves ofB. oleracea var.botrytis and cultured in KM8p medium (Kao andMichayluk 1975) underwent sustained divisions in about 0.1% population to eventually produce callus, whereas mesophyll protoplasts from either field grown orin vitro raised plants failed to divide. The callus readily differentiated on Murashige-Skoog medium as modified for shoot culture (Binding 1974) to give rise to shoot and roots. 相似文献
10.
Development and Characterization of a Nonmorphogenetic Cell Line of Wheat (Triticum aestivum) 总被引:1,自引:1,他引:0
Arron C. Guenzi Kay Scheets J. Larry Green John P. Fellers 《Plant Cell, Tissue and Organ Culture》2004,78(1):23-28
This study was conducted to compare characteristics of a wheat (Triticum aestivum L.) cell line to those of the maize (Zea mays L.) black Mexican sweet (BMS) cell line and to compare protoplasts isolated from suspension cells of these cell lines. The
wheat cell line was established from immature-embryo derived callus of the experimental line ‘ND7532’ and was conditioned
for growth in suspension culture. For both cell lines, measurements of packed cell volume (PCV), fresh weight (FW), and dry
weight (DW) were taken at 3 day intervals from suspension cultures. Measurements of FW of calluses cultured from suspension
cells of both cell lines were taken at 6 day intervals. The morphogenetic potential of the wheat ND7532 cell line was tested
in both callus and suspension cultures using media promoting regeneration and/or organogenesis. Growth rates of ND7532 cells
in suspension culture were comparable to those of BMS cells. However, relative growth rates of calluses recovered from ND7532
suspension cells were slower than those of calluses recovered from BMS suspension cells. The ND7532 cell line has very limited
morphogenetic potential and has been maintained as rapidly growing callus tissue for 11 years. Yields of protoplasts from
suspension cells of the two cell lines were comparable, though ND7532 protoplasts were typically smaller. The wheat cell line
has is now designated ND7532-NM (nonmorphogenetic) and is available for cellular and molecular biology research. 相似文献
11.
E. Nenz F. Pupilli F. Damiani S. Arcioni 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1996,93(1-2):183-189
Interspecific somatic hybrid plants were obtained by symmetrical electrofusion of mesophyll protoplasts of Medicago sativa with callus protoplasts of Medicago arborea. Somatic hybrid calli were picked manually from semi-solid culture medium after they were identified by their dual color in fluorescent light. Twelve putative hybrid calli were selected and one of them regenerated plants. The morphogenesis of the somatic hybrid calli was induced by the synthetic growth regulator 1,2 benzisoxazole-3-acetic acid. Somatic hybrid plants showed intensive genome rearrangements, as evidenced by isozyme and RFLP analysis. The morphology of somatic hybrid plants was in general intermediate between the parents. The production of hybrids by protoplast fusion between sexually incompatible Medicago species is related to the in vitro respon siveness of the parental protoplasts. The possibility of using somatic hybrid plants in alfalfa breeding is discussed. 相似文献
12.
Summary Axenic shoot cultures ofCapsicum annuum cv.California Wonder were used as the source for isolation of protoplasts from mesophyll cells. Protoplasts underwent sustained mitotic activity and proliferated to form callus masses on NT or DPD medium enriched with 2,4-D, NAA and BAP each at 1 mg/l level. The callus could be differentiated into whole plants on the differentiation media and plants floweredin vitro under long day conditions. 相似文献
13.
Andrew Hudson Rosemary Carpenter Enrico S. Coen 《Molecular & general genetics : MGG》1987,207(1):54-59
Summary The nivea locus of Antirrhinum majus encodes the enzyme chalcone synthase required for the synthesis of red anthocyanin pigment. The stable allele niv-44 contains an insertion in the nivea gene (Tam2) which has all the structural features of a transposable element. We have shown that this insertion can excise from the nivea locus when niv-44 is combined with another allele (niv-99) in a heterozygote. Activation of Tam2 excision is caused by a factor tightly linked to the niv-99 allele and may be due to complementation between Tam2 and a related element, Tam1. Factors which repress the excision of Tam2 and Tam1 are also described. Repression is not inherited in a simple mendelian way. Many stable mutations may be due to the insertion of transposable elements. Our data suggest that their stability may be due to the absence in the genome of activating factors and to the presence of repressors. 相似文献
14.
High frequency callus formation from maize protoplasts 总被引:3,自引:0,他引:3
S. R. Ludwig D. A. Somers W. L. Petersen R. F. Pohlman M. A. Zarowitz B. G. Gengenbach J. Messing 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1985,71(2):344-350
Summary A solid feeder layer technique was developed to improve callus formation of Black Mexican Sweet maize (Zea mays L.) suspension culture protoplasts. Protoplasts were plated in 0.2 ml liquid media onto a cellulose nitrate filter on top of agarose-solidified media in which Black Mexican Sweet suspension feeder cells were embedded. Callus colony formation frequencies exceeding 10% of the plated protoplasts were obtained for densities of 103–105 protoplasts/ 0.2 ml, which was 100- to 1,000-fold higher than colony formation frequencies obtained for conventional protoplast plating methods such as liquid culture or embedding in agarose media. Compared with conventional methods, the feeder layer method gave higher colony formation frequencies for three independently maintained Black Mexican Sweet suspension lines. Differences among the three lines indicated that colony formation frequencies might also be influenced by the suspension culture maintenance regime and length of time on different 2,4-dichlorophenoxyacetic acid concentrations. The callus colony formation frequency reported is an essential prerequesite for recovering rare mutants or genetically transformed maize protoplasts. 相似文献
15.
Summary
Entomophthora muscae (C.) Fres. can be grownin vitro as protoplasts. Light and electron microscopical studies of thein vitro developed protoplasts have demonstrated the absence of an organized wall over the protoplasmic Con A-positive membrane at all stages of growth. The cytological organization is typical of the Entomophthorales with condensed chromatin in the interphase nuclei and small eccentric metaphase spindles. Long strands of endoplasmic reticulum, microubules and vesicles surrounding the plasmalemma may be involved in maintaining the precise shape ofE. muscae protoplast. Starvation of the fungus induces the formation of hyphal bodies after deposition of Con A- and WGA-positive wall material at the plasmalemma surface.Abbreviations Con A
concanavalin A
- DH
Drosophila cell culture medium
- FITC
fluorescein isothiocyanate
- GLEN
glucose-lactal-bumin-yeast extract-NaCl culture medium for protoplasts
- HBL
hyphal body-like protoplasts
- MM
Mitsuhashi and Maramorosch' insect cell culture medium
- PATAg
periodic acid-thiocarbohydrazide-silver proteinate technique
- PBN
phosphate buffer with NaCl
- S
spherical protoplasts
- WGA
wheat germ agglutinin 相似文献
16.
Conditions have been developed that induce maize (Zea mays L.) protoplasts to re-synthesize cell walls and to initiate cell divisions. Two types of embryogenic maize callus were used as a source of protoplasts: a heterogeneous callus (Type I) derived from immature embryos after three weeks in culture, and a friable, rapidly growing callus (Type II) selected from portions of the Type I callus. Many variables in the growth conditions of the donor tissue (type of medium, transfer schedule, age of callus), protoplast isolation solutions (pH, osmolarity, type and concentration of cell wall hydrolyzing enzymes, addition of polyamines) and conditions (amount of time in enzyme, amount of tissue per volume of enzyme incubation medium, agitation, preplasmolysis of source tissue, type of callus), and purification procedures (filtration and-or flotation), were found to affect both yield and viability of protoplasts (based upon fluorescein-diacetate staining). Our isolation procedure yielded high numbers of viable, uninucleated maize callus protoplasts which were densely cytoplasmic and varied in size from 20 to 50 m in diameter. Protoplasts plated in solid medium formed walls and divided several times. Of several gelling agents tested for protoplast propagation, only agarose resulted in protoplasts capable of sustained divisions leading to the formation of microcalli. Plating efficiency was established over a wide range of protoplast densities (103–107 protoplasts/ml). Highest plating efficiency (25%) was obtained at 1·106 protoplasts/ml). The resulting microcalli grew to be dense clusters of about 0.1–0.5 mm in diameter and then stopped growing. Nurse cultures of maize and carrot (Daucus carota L.), were used to establish that individual protoplasts (not contaminating cells or cell clusters) formed walls and divided. Nurse cultures also increased the efficiency of microcallus formation from protoplasts.Abbreviations 2,4-D
2,4-dichlorophenoxyacetic acid
- MS
Murashige and Skoog (1962) salts
- MS 1D
Murashige and Skoog salts with 1 mg/l 2,4-D
- MS 2D
Murashige and Skoog salts with 2 mg/l 2,4-D
- N6
medium of Chu et al. (1975)
- NN67-mod
medium of Nitsch and Nitsch (1967) as modified in the present paper
- FDA
fluorescein diacetate
- LMP
low melting point 相似文献
17.
Green fluorescent protein (GFP) was successfully used as a visual reporter at various stages of carrot (Daucus carota L.) transformation. GFP-fluorescence was non-invasively observed in protoplasts, callus and plants after the delivery of
mgfp5-er gene using two transformation methods: direct DNA transfer into polyethylene glycol (PEG) -treated protoplasts and inoculation
of root discs with Agrobacterium rhizogenes. Transient GFP-expression was detected in the treated protoplasts and monitored during the first week of the cell culture
until the stable level of expression was observed. It was useful for the comparison of protoplast susceptibility to DNA uptake
and the transgene expression as the fluorescence declined with various rates depending on the used carrot genotype and PEG-concentration.
GFP-monitoring in callus enabled the selection of stably expressing lines. It also allowed verification of the homogeneous
tissue composition with regard to the expression of the transgene. In plants, GFP-performance depended on the assayed tissue
and organ despite of the constitutive 35S promoter. The expression was visually detected in both vegetative and generative
parts, but particularly strong fluorescence was observed in leaf marginal meristems, petioles, stems, and styles. Those tissues
can be convenient for examination of the transgenic plants during their growth. The results encourage that GFP is a valuable
reporter and can be routinely used for optimization of transformation protocol, selection of transformants and monitoring
transgenic carrot. 相似文献
18.
Viable protoplasts of Taxus yunnanensis were isolated from friable, light yellow callus. Protoplast yield was dependent on callus age, with a maximum from 20-day-old
callus. Protoplasts were induced to undergo sustained divisions and to form cell colonies when cultured in medium consisting
of B5 salts, KM vitamin and organic components, 0.45 M fructose, 3.0 mg l-1 2,4-dichlorophenoxyacetic acid and 0.1 mg l-1 kinetin. The planting density was 2.5–3.0×105 protoplasts per ml of culture medium. Cell-free extract from callus enhanced protoplast division and the highest plating
efficiency was about 7%. Protoplast-derived colonies showed significant variations in both growth and paclitaxel content.
A negative correlation existed between paclitaxel accumulation in colonies and their growth to some extent (r = −0.4485).
Among 70 colonies isolated from the heterogeneous protoplast cultures, colony TY-7 accumulated the highest paclitaxel content.
Paclitaxel accumulation in colony TY-7 was not great enough to produce paclitaxel for commercial purposes, however, success
in inducing colony formation from T. yunnanensis protoplasts provides an opportunity to obtain cell lines with high paclitaxel productivity from mutagenized protoplast cultures.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
19.
Transgenic plants with the herbicide-resistance gene (bar gene) were obtained via organogenesis from isolated mesophyll protoplasts of Nierembergia repens after applying electroporation. Transient β-glucuronidase (GUS) activity of electroporated protoplasts assayed 2 days after
applying an electric pulse showed that optimum condition (transient GUS activity 319 pmol 4 MU/mg per min and plating efficiency
2.43%) for electroporation was 0.5 kV/cm in field strength and 100 μF in capacitance. The protoplasts electroporated with
the bar gene at this condition initiated formation of microcolonies on medium after 2 weeks. After 4 weeks of culture, equal volume
of fresh 1/2-strength Murashige and Skoog (MS) medium containing 0.2 mg/l bialaphos was added for selection of transformed
colonies. After 6 weeks of culture, growing colonies were transferred onto regeneration medium containing 1.0 mg/l bialaphos,
on which they formed adventitious shoots 1–2 months after electroporation. The adventitious shoots rooted easily after transfer
onto MS medium with bialaphos lacking plant-growth regulators. Transformation of these regenerants with the bar gene was confirmed by Southern analysis. Some of the transformants showed strong resistance to the application of bialaphos
solution at 10.0 mg/l. 相似文献
20.
Stephen R. Millam Alan T. H. Burns Trevor J. Hocking Ken J. Cattell 《Plant Cell, Tissue and Organ Culture》1988,12(3):285-290
A method is described for regenerating callus from mesophyll protoplasts of a winter variety of Brassica napus. The method combines the use of Ficoll in an initial liquid medium, enhancing early protoplast division and cell colony formation, with a transfer to an agarose system after 10 days culture to give rapid microcalli formation. Further transfers resulted in callus regeneration and the initiation of organogenesis. 相似文献