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101.
To identify conserved and functionally important features in the intergenic sequences of ribosomal DNAs, the nucleotide sequence of the 18–25S rRNA intergene region in tobacco rDNA was determined and compared to that of other higher plants. Unlike previous comparisons of more diverse organisms, sufficient sequence homology is retained in the higher plants to examine the evolutionary changes which make these regions diverse. Estimates of the secondary structure permit the identification of a core-like structure which appears to maintain the processed sites in close proximity and can be identified in the more divergent sequences. 相似文献
102.
Mauricio M. Bustos Fatma A. Kalkan Kathryn A. VandenBosch Timothy C. Hall 《Plant molecular biology》1991,16(3):381-395
An intron-less phaseolin gene [15] was used to express phaseolin polypeptides in transgenic tobacco plants. The corresponding amounts of phaseolin immunoreactive polypeptides and mRNA were similar to those found in plants transformed with a bean genomic DNA sequence that encodes an identical -phaseolin subunit. These results justified the use of the intron-less gene for engineering of the phaseolin protein by oligonucleotide-directed mutagenesis. Each and both of the two Asn residues that serve as glycan acceptors in wild-type phaseolin were modified to prevent N-linked glycosylation. Wild-type (wti–) and mutant phaseolin glycoforms (dgly
1, dgly
2 and dgly
1,2) were localized to the protein body matrix by immunogold microscopy. Although quantitative slot-blot hybridization analysis showed similar levels of phaseolin mRNA in transgenic seed derived from all constructs, seed from the dgly
1 and dgly
2 mutations contained only 41% and 73% of that expressed from the wild-type control; even less (23%) was present in seed of plants transformed with the phaseolin dgly
1,2 gene. Additionally, the profile of 25–29 kDa processed peptides was different for each of the glycoforms, indicating that processing of the full-length phaseolin polypeptides was modified. Thus, although targeting of phaseolin to the protein body was not eliminated by removal of the glycan side-chains, decreased accumulation and stability of the full-length phaseolin protein in transgenic tobacco seed were evident.Abbreviations bp
base pair(s)
- DAF
days after flowering
- GUS
-glucuronidase
- kb
kilobase
- kDa
kilodalton 相似文献
103.
The iaaM and iaaH genes of Agrobacterium tumefaciens and Agrobacterium rhizogenes play an important role in crown gall and hairy root disease. The iaaM gene codes for tryptophan monooxygenase which converts tryptophan into indole-3-acetamide (IAM). IAM is converted into the auxin indole-3-acetic acid (IAA) by indoleacetamide hydrolase, encoded by the iaaH gene. In functional studies on the activity of the iaa genes of the TB region of the A. tumefaciens biotype III strain Tm4, the frequently used 35S--glucuronidase (35S-UidA or GUS) marker gene was found to inhibit IAA synthesis and root induction encoded by the TB iaa genes. To exert this inhibition, the 35S-UidA gene must be cotransferred with the iaaH gene. The 35S promoter alone is sufficient to cause the inhibitory effect. 相似文献
104.
105.
Shoot apical meristems were used to establish regenerative axillary bud cultures of 9 muscadine grape cultivars. Meristems taken from 10 cm long shoots had less contamination (3%) and a higher survival rate (94%) than those from shorter or longer shoots. Of media tested, MS, 1/2 MS, and C2D resulted in equivalent shoot proliferation rates, whereas, WPM produced stunted shoots. When pooling results for 3 cultivars, 5, 10 and 20 M BA and 5 M TDZ produced the highest average number of shoots per cultured apex (3.4–3.8). However, shoots produced with TDZ were stunted and did not root well. For rooting of shoots directly in potting mix, a rooting powder pretreatment significantly increased the number of roots per shoot but did not affect percent rooting or root length. For rooting in vitro, 1 M NAA significantly increased all parameters measured. Although more shoots rooted in vitro than in vivo (77% vs. 46%), the latter was judged preferable since acclimatized plants were produced in less time and a major culture step was eliminated. Significant differences among cultivars were noted for measured responses in all experiments.Abbreviations BA
benzyladenine
- Kin
kinetin
- MS
Murashige & Skoog (medium)
- NAA
naphthaleneacetic acid
- TDZ
thidiazuron
- WPM
woody plant medium 相似文献
106.
Nicola J. Atkinson H. John Newbury Brian V. Ford-Lloyd 《Plant Cell, Tissue and Organ Culture》1991,27(1):77-79
A broadly applicable method for the successful induction of root systems in a number of cultivars of A. majus has been determined. This involves a double filter-paper bridge with a liquid medium for root induction and allows the transfer of culture-grown plantlets to a glasshouse environment with minimal disturbance to the plant as a whole. 100% survival of transferred plantlets has been achieved with the inclusion of a few simple precautions upon shoot transfer and during the initial stages of plant establishment in vivo. 相似文献
107.
High-level expression of a tobacco chitinase gene in Nicotiana sylvestris. Susceptibility of transgenic plants to Cercospora nicotianae infection 总被引:12,自引:0,他引:12
Jean-Marc Neuhaus Patricia Ahl-Goy Ursula Hinz Susan Flores Frederick Meins Jr. 《Plant molecular biology》1991,16(1):141-151
Endochitinases (E.C. 3.2.14, chitinase) are believed to be important in the biochemical defense of plants against chitin-containing fungal pathogens. We introduced a gene for class I (basic) tobacco chitinase regulated by Cauliflower Mosaic Virus 35S-RNA expression signals into Nicotiana sylvestris. The gene was expressed to give mature, enzymatically active chitinase targeted to the intracellular compartment of leaves. Most transformants accumulated extremely high levels of chitinase-up to 120-fold that of non-transformed plants in comparable tissues. Unexpectedly, some transformants exhibited chitinase levels lower than in non-transformed plants suggesting that the transgene inhibited expression of the homologous host gene. Progeny tests indicate this effect is not permanent. High levels of chitinase in transformants did not substantially increase resistance to the chitin-containing fungus Cercospora nicotiana, which causes Frog Eye disease. Therefore class I chitinase does not appear to be the limiting factor in the defense reaction to this pathogen. 相似文献
108.
A protoplast to plant system in roses 总被引:7,自引:0,他引:7
Derek Matthews John Mottley Imelda Horan Andrew V. Roberts 《Plant Cell, Tissue and Organ Culture》1991,24(3):173-180
High yields of protoplasts were isolated from embryogenic suspension cultures of Rosa persica x xanthina and Rosa wichuraiana using an enzyme mixture comprising 20 g l-1 cellulase Onozuka R10, 1 g l-1 Pectolyase Y-23 and 10 g l-1 hemicellulase. Agarose-immobilized protoplasts gave the most consistent growth at a plating density of 5×104 protoplasts ml-1 on the basic medium of Kao & Michayluk (KM8p) containing 2 mg l-1 naphthaleneacetic acid and 1 mg l-1 benzylaminopurine. At 25°C in the dark, 0.004% of R. persica x xanthina protoplasts developed into colonies. Using similar culture conditions, but with a plating density of 9×104 protoplasts ml-1, 0.017% of R. wichuraiana protoplasts developed into colonies. On transfer of R. persica x xanthina colonies to Schenk & Hildebrandt's medium containing 3 mg l-1 2,4-dichlorophenoxyacetic acid, globular and later stage embryos were formed. Approximately 30% of these embryos developed into plantlets on transfer to basal Schenk & Hildebrandt's medium. Further development of the plantlets took place on cellulose plugs (Sorbarods) soaked in Murashige & Skoog's medium containing 0.05 mg l-1 naphthaleneacetic acid, 0.05 mg l-1 indole-3-butyric acid and 0.1 mg l-1 benzylaminopurine. Rose breeding is now open to the full range of in vitro genetic manipulation techniques involving protoplast technology. 相似文献
109.
S. J. Ochatt 《Plant Cell, Tissue and Organ Culture》1991,25(2):161-167
Leaf protoplasts of axenic shoot cultures of Lonicera nitida cv Maigrun underwent sustained division to give multicellular colonies (microcalli) on a modified, ammonium-free MS (Murashige & Skoog) medium containing 0.5 mg l-1 NAA (1-naphthaleneacetic acid), 1.0 mg l-1 BAP (6-benzylaminopurine) and 150 mg l-1 casein enzymatic hydrolysate. Callus was produced upon transfer of cell colonies to MS medium with 2.0 mg l-1 NAA and 0.2 mg l-1 BAP. About 110 days from isolation protoplast-derived shoots were regenerated on a half-strength MS medium with 0.01 mg l-1 NAA, 5.0 mg l-1 BAP, 0.5 mg l-1 zeatin and a complex mixture of group B vitamins. The replacement of such mixture by 250 mg l-1 casein enzymatic hydrolysate promoted rhizogenesis in calli, with shoot buds being subsequently regenerated from the protoplast-derived roots. Micropropagation of protoplast-derived shoots (of either origin) was difficult, due to a strong apical dominance, but could be accomplished by transferring single-node explants to half-strength MS medium with 1.5 mg l-1 BAP. Such shoots were, in turn, successfully rooted and transferred to the glasshouse where they completed acclimatization.Abbreviations BAP
6-benzylaminopurine
- CPW
Power et al. (1989) medium
- 2,4-D
2,4-dichlorophenoxyacetic acid
- FDA
fluorescein diacetate
- F.P.E.
final plating efficiency
- f.wt.
fresh weight
- IAA
4-indole-3yl-acetic acid
- IBA
4-indole-3yl-butyric acid
- I.P.E.
initial plating efficiency
- MES
2-N-morpholinoethane sulfonic acid
- M.P.E.
intermediate plating efficiency
- MS
Murashige & Skoog (1962) medium
- NAA
1-naphthaleneacetic acid
- PVP-10
polyvinylpirrolidone
- Av MW 10,000, TIBA
2,3,5-tri-iodobenzoic acid
- Z
zeatin 相似文献
110.
Margarita Cacho Margarita Morán María Teresa Herrera Jorge Fernández-Tárrago 《Plant Cell, Tissue and Organ Culture》1991,25(2):117-123
The effects of the auxins 2,4-D, NAA and IAA either alone or in combination with kinetin or BA were investigated to assess the morphogenetic potential of leaf, root and hypocotyl explants of Digitalis thapsi. Calluses were obtained from the three explants in basal medium without the addition of growth regulators and in leaves, the calluses formed roots. Application of 2,4-D, NAA or BA increased callus formation. The presence of NAA induced root formation and that of BA induced shoot formation via callus interphase. Indole-3-acetic acid alone only induced the generation of roots in the hypocotyl callus. Kinetin was ineffective in all the explants tested. Combinations of NAA with kinetin or BA were more effective in inducing organogenesis in leaf explants. Optimum responses were obtained in hypocotyl and root explants by using IAA in combination with BA, the highest rate of shoot regeneration being observed in hypocotyl explants.Rooting of the differentiated shoots was readily achieved in media without growth regulators. Regenerated plantlets were transferred to soil and grew with a survival rate of 70%.Abbreviations BA
benzyladenine
- 2,4-D
2,4-dichlorophenoxyacetic acid
- IAA
indoleacetic acid, Kin-kinetin
- NAA
naphthaleneacetic acid 相似文献