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PubMed2006

Genetic transformation of Centaurium erythraea Rafn by Agrobacterium rhizogenes and the production of secoiridoids.

Hairy roots of Centaurium erythraea were obtained by infection with Agrobacterium rhizogenes strain LBA 9402. They spontaneously regenerated adventitious shoots in Woody Plant liquid medium without growth regulators. The shoots were grown continuously in Murashige and Skoog (MS) liquid or agar solidified media supplemented with 0.1 mg l(-1) indole-3-acetic acid and 1.0 mg l(-1) 6-benzylaminopurine. These shoots produced roots 4 weeks after transfer into agar-solidified MS medium without phytohormones. Regenerated plants grown and flowered under greenhouse conditions. The transgenic value of the regenerated plants was confirmed by the polymerase chain reaction amplification. Transformation by Agrobacterium rhizogenes alters plant morphology and production of secoiridoid glucosides. The level of secoiridoids was also modified by development stage of transformed plants. The total content of the compounds (expressed as the sum of gentiopicroside, sweroside and swertiamarin) in 10-week old pRi-transformed regenerants was 280 mg g(-1) dry weight and was 8-times the content in the sample of commercially available C. erythraea herb.

Centaurium↗

PubMed1996

Enhanced root production in Haplopappus gracilis grown under spaceflight conditions.

The production and growth of roots in two aseptically maintained clonal populations of Haplopappus gracilis (family Compositae), each with a distinctive pattern of root production, were studied after they had been exposed to space for 5 days aboard a NASA Space Shuttle. Total root production of both populations was 67-95% greater when compared with their Earth-grown controls. Roots were generated: (1) laterally from pre-formed roots, the tips of which had been severed at the time of plantlet insertion into a "horticultural foam" substrate supplied with a nutrient solution; (2) adventitiously from the basal or cut-end portion of shoots; (3) de novo, i.e. from primordial which were non-existent at the outset of the experiment. Roots grew in all directions in space but were uniformly positively gravitropic in ground controls. In space and on Earth, both clonal populations maintained their clone-specific root formation and growth characteristics and produced an equivalent amount of tissue when compared to each other. As on Earth, and as expected, there were fewer and shorter roots on plantlets that formed floral buds. The significance of altered moisture distribution in the "horticultural foam" substrate in space for root growth and the significance of our findings for growing plants in altered gravity environments are discussed.

Computer Simulation↗

PubMed2006

Strawberry (Fragaria x ananassa).

Genetic transformation in strawberry (Fragaria spp.) can be achieved by using the Agrobacterium-mediated procedure on leaves from in vitro proliferated shoots. Regardless of the sufficient regeneration levels achieved from leaf explants of some commercial strawberry genotypes, the regeneration of transformed strawberry plants remains difficult and seems to be strongly genotype dependent. In fact, the main factors that play an important role in the success of strawberry genetic transformation are the availability of both an efficient regeneration protocol and an appropriate selection procedure of the putative transgenic shoots. The strawberry genetic transformation protocol herein described relates to two genotypes resulting from our experience with the highest regeneration and transformation efficiency. The study includes an octoploid Fragaria x ananassa cultivar (Sveva) and a diploid F. vesca cultivar (Alpina W.O.). All the different steps related to the leaf tissue Agrobacterium infection, co-culture, and selection of regenerating adventitious shoots, as well as the following identification of selected lines able to proliferate and root on the selective agent (kanamycin), will be described.

Agrobacterium tumefaciens↗

PubMed2004

[Establishment of plantlet regeneration system of medicinal plant Aconitum coreanum].

OBJECTIVE: To set up the rapid propagation and plantlet regeneration system of medicinal plant Aconitum coreanum (Levi.) Rpaics. METHOD: Adventitious buds and regenerated plantlet were obtained by shoot tip culture through different media and combination of plant growth regulators. RESULT: MS medium was the optimal medium for differentiation and proliferation of shoot tip. MS medium with 6-BA 2 to approximately 5 mg/L was found to be most suitable for the induction of bud. MS with 6-BA 2 mg/L + GA3 1 to approximately 5 mg/L or adenine 1 to approximately 5 mg/L was best combination for the growth and proliferation of adventitious buds, and MS with IBA 0.5 to approximately 1 mg/L for the induction of root. CONCLUSION: Tip culture may be used as a useful method to get regenerated plantlet of Aconitum coreanum under certain conditions.

Aconitum↗

PubMedDate not supplied

[In vitro regeneration and callogenesis in tissue culture of floral organs of the genus Iris (Iridaceae)].

We tested the differentiation and morphogenetic capacity of floral organs of Iris ensata, I. setosa, and I. sanguinea cultured in vitro. Organogenesis through direct formation of shoots from explants, callogenesis, and floral organogenesis were demonstrated in I. ensata callus culture in vitro. These processes depended on the plant species and on the content of phytohormones in the medium. Adventitious shoots proved to develop on the basal part of the perianth tube and on the apical part of the ovary, while roots were not formed. Direct organogenesis was induced by the following phytohormones: alpha-naphthylacetic acid and 6-benzylaminopurine for I. ensata and 2,4-dichlorophenoxyacetic acid and 6-benzylaminopurine for I. setosa and I. sanguinea; while callogenesis was induced by 2,4-dichlorophenoxyacetic acid. The obtained data indicate that development of adventitious structures from iris floral organs requires the presence of 6-benzylaminopurine in the growth medium.

Adenine↗

PubMed2004

In vitro morphogenesis in zygotic embryo cultures of neem (Azadirachta indica A. Juss.).

Immature zygotic embryo cultures of neem yielded highly regenerative cultures, with the response varying with the embryo stage at culture. Early dicotyledonous stage embryos were the most responsive followed by torpedo stage embryos. The embryo cultures differentiated three types of regenerants: somatic embryos (SEs), shoot buds and neomorphs. SEs exhibited morphological abnormalities such as pluricotyledony, fusion of cotyledons and absence of cotyledons. Although these SEs showed secondary embryogenesis, the occurrence of normal dicotyledonous embryos was extremely rare. On MS basal medium 3% of SEs developed a long tap root but a plumular shoot did not appear. However, it was possible to regenerate plantlets from immature zygotic embryo cultures of neem via neomorph formation and adventitious shoot bud formation. The transplantation survival of these plants was more than 80%.

Azadirachta↗

PubMed2005

[Plant regeneration from callus of Changiums myrnioides].

OBJECTIVE: To set up the callus culture system of Changiums myrnioides and the plantlet regeneration system by the proliferation and differentiation of callus. METHOD: The segment of stems used as the explants were cultured on dedifferentiation and differentiation medium supplied with different auxin and cytokinin. RESULT: MS medium with NAA 0.5 - 1.0 mg/L + KT 0.1 mg/L was best combination for the induction of callus, MS medium with 6 - BA 1 - 2 mg/L + GA 1 - 2 mg/L was suitable for the differentiation of adventitious buds, and MS medium with IBA 0.5 - 1 mg/L was suitable for the induction of root. CONCLUSION: Callus culture may be used as a useful method to get regenerated plantlet of Changiums myrnioides under certain condition.

Apiaceae↗

PubMed1995

The control of ingress of albumin into developing enamel from adjacent dentine of the rat incisor.

The present study used an immunohistochemical approach to map the distribution of albumin within the dentine adjacent to the developing enamel of both impeded and unimpeded rat incisors to determine if the dentine could be a possible route of entry for this protein into the developing enamel matrix. In dentine adjacent to the secretory and transition stages of the developing enamel, the dentinal tubules were labelled only over approximately the pulpal quarter of their length. The bulk of the dentine showed no labelling. However, labelling within the dentine appeared at the ADJ at a position approximately 2.5 mm occlusal to the distal root of the first molar, adjacent to enamel with no visible residual matrix. The results of this study suggest that adventitious ingress of albumin into enamel from the dentine is restricted during enamel secretion and can only potentially occur once enamel maturation has been initiated.

Albumins↗

PubMed2005

Adventitial inversion technique without the aid of biologic glue or Teflon buttress for acute type A aortic dissection.

OBJECTIVE: This study was performed to evaluate the clinical usefulness of the adventitial inversion technique in acute type A aortic dissection, with special attention to the impact of this procedure on the postoperative status of false lumen evaluated by computed tomographic scan. METHODS: From March 2001 to November 2004, 18 consecutive patients underwent emergent surgery for acute type A aortic dissection. Supracoronary graft replacement was performed in all the patients (ascending aorta/hemiarch replacement: 13/18=72%, total arch replacement: 5/18=28%). The adventitial inversion technique was used for both the proximal and the distal stump constructions of the dissected aortic wall without the aid of Teflon felt or biologic glue. Aortic regurgitation was treated with resuspension of the aortic commissures. RESULTS: There were two hospital deaths and the overall hospital mortality rate was 11.1%. The mean postoperative blood loss was 635+/-214 ml and no reexploration was required in any of the patients. Postoperative computed tomography showed closure of the false lumen in aortic root, aortic arch, and proximal descending thoracic aorta in all of the surviving patients. Postoperative echocardiography demonstrated no aortic regurgitation in any of the patients. Two patients died late postoperatively from unrelated causes to aortic dissection. The remaining 14 patients are doing well without a second-stage operation for aortic root or distal aortic lesions during the follow-up period of 7-51 months (mean: 28+/-14 months). CONCLUSIONS: The adventitial inversion technique provides an excellent immediate hemostasis and facilitates thrombotic closure of the proximal and the distal false lumen in the treatment for acute type A aortic dissection.

Acute Disease↗

PubMed1992

Altered morphology in transgenic tobacco plants that overproduce cytokinins in specific tissues and organs.

An auxin-inducible bidirectional promoter from the soybean SAUR gene locus was fused to a reporter gene in one direction and a cytokinin biosynthetic gene in the opposite direction and the expression of these fused genes was examined in transgenic tobacco. The Escherichia coli uidA gene, which encodes the enzyme beta-glucuronidase (GUS), was used as the reporter gene and the Agrobacterium tumefaciens ipt gene, which encodes the enzyme isopentenyl transferase, was used as the cytokinin biosynthetic gene. These constructs allowed the overproduction of cytokinins in tobacco in a tissue- and organ-specific manner. Localized overproduction of cytokinins was monitored using the GUS reporter gene and measured by an ELISA assay. The tissue- and organ-specific overproduction of cytokinins produced a number of morphological and physiological changes, including stunting, loss of apical dominance, reduction in root initiation and growth, either acceleration or prolonged delayed senescence in leaves depending on the growth conditions, adventitious shoot formation from unwounded leaf veins and petioles, altered nutrient distribution, and abnormal tissue development in stems. While some of these morphological changes result directly from the localized overproduction of cytokinins, other changes probably result from the mobilization of plant nutrients to tissues rich in cytokinins.

Amino Acids↗

PubMed1983

Distribution of visual attention over space.

Subjects viewed 3 X 3 grids in which different subsets of the nine squares were designated as "figure," either by physical shading of those squares or by a verbal instruction to imagine those squares as shaded. The time taken by participants to respond "on" or "off" the figure was measured for single or multiple probe dots, which all appeared on or off the figural subset together, and which had already been shown to be equally detectable against shaded or unshaded squares and in all nine locations within the grid. In contrast to the set-size effect generally found in experiments on memory scanning, reaction time did not necessarily increase with the number of squares in the figural subset. Instead, the critical variable, which in previous research may often have adventitiously covaried with set size, was the spatial compactness of the subsets (as indexed by square-root-area over perimeter): Probes of less compact figures required more time to classify correctly. Subjects were evidently more successful in confining their attention to sets of mutually proximal items. Reasons are given for believing that this principle may also apply in the more abstract representational or semantic spaces that determine reaction times and errors in various other cognitive tasks.

Attention↗

PubMed2006

[Tissue culture and high-frequency plant regeneration of buckwheat (Fagopyrum esculentum Moench)].

Different explants and compounding proportions of different hormones were comparatively studied in tissue culture of Fagopyrum esculentum Moench and thereafter an efficient plant-regeneration system was established by in vitro F. esculentum Moench culture. On MS medium containing 2.0 mg/L 2,4-D and 1.0 mg/L 6-BA, 89.6% cotyledon segments could be induced to produce calli; however, on MS medium containing 2.0 mg/L 2,4-D and 1.0-2.0 mg/L 6-BA, the induction rate of hypocotyl segments could reach as high as 100%. On MS medium containing 2.0 mg/L 6-BA, 0.1 mg/L IAA and 1 mg/L KT, adventitious buds could be regenerated indirectly from calli or directly from explants, the differentiation rates of cotyledon-derived calli and hypocotyl-derived calli were 42.5% and 73.6% respectively; the calli coming from hypocotyl segments differentiated evidently at a higher rate than the calli originated from cotyledon segments. Well-grown adventitious buds were inoculated on 1/2 MS medium containing 1.0 mg/L IBA and 0.5 mg/L NAA, 100% rooting frequency was obtained. Plantlets grew well and appeared normal with no mortality after being transplanted to soil. Moreover, the survival rate of plantlets reached 91.6%.

Fagopyrum↗

PubMed2005

Stable genetic transformation of Larix gmelinii L. by particle bombardment of zygotic embryos.

We report a new protocol for the stable transformation of Larix gmelinii. Thirty mature zygotic embryos precultured for 3 days on solid medium supplemented with benzyladenine were bombarded with plasmids pUC-GHG (GUS, HPT, and GFP genes) or pBI221-HPT (HPT and GUS genes). After a 2-month culture on selection medium, hygromycin-resistant calli appeared on the surfaces of the necrotic embryos. The frequencies of embryos with resistant calli were 18.4% and 17.4% in the transformations with pUC-GHG and pBI221-HPT DNA, respectively. More than 20 adventitious shoots formed from each of the transgenic calli. Of 17 elongated shoots selected for culturing on a rooting medium, five shoots rooted after 2 months. Expression of the GFP and GUS genes was detected in the resistant tissues by microscopic observations and by a histological GUS activity assay, respectively. PCR and Southern analysis confirmed the stable insertion of the introduced DNA into the genome.

Biolistics↗

PubMed2002

PkMADS1 is a novel MADS box gene regulating adventitious shoot induction and vegetative shoot development in Paulownia kawakamii.

Direct regeneration of shoot buds in vitro is an important technique in plant genetic manipulation. We describe the isolation and functional characterization of a novel MADS box cDNA (PkMADS1) from Paulownia kawakamii leaf explants undergoing adventitious shoot regeneration. mRNA gel blot analysis confirmed the expression of PkMADS1 in the shoot-forming cultures, but no signal was observed in the callus-forming cultures. PkMADS1 transcripts were also detected in shoot apices, but not in root apices, initial leaf explants or the flower. In situ hybridization revealed that its expression was restricted to developing shoot primordia in the excised leaf cultures, suggesting a role for this gene in adventitious shoot formation. Transgenic Paulownia plants over-expressing the PkMADS1 gene showed some changes in phenotype, such as axillary shoot formation. In the antisense transformants, shoots were stunted and had altered phyllotaxy, and, in some lines, the shoot apical meristem appeared to have been used up early during shoot development. Leaf explants from the antisense transgenic plants showed a tenfold decrease in shoot regeneration compared with explants from sense transformants or wild-type. Our results show that PkMADS1 is a regulator of shoot morphogenesis.

Amino Acid Sequence↗

PubMedDate not supplied

CT findings of ruptured intramural hematoma of the aorta extending along the pulmonary artery.

Mediastinal hematoma extending along the pulmonary artery is a rare complication of Stanford type A classic (double-barreled) aortic dissection. Rupture from the posterior aspect of the aortic root penetrates the shared adventitia of the aorta and pulmonary artery. From this location, hematoma can spread along the adventitial planes of the pulmonary arteries out into the lungs. We report a case of ruptured intramural hematoma of the aorta (IMH) extending along the pulmonary artery. To our knowledge, this finding in patients with IMH has not been reported in the literature.

Aged, 80 and over↗

PubMed2006

Shoot bud regeneration from different explants of Bacopa monniera (L.) Wettst. by trimethoprim and bavistin.

A mass in vitro propagation system devoid of growth regulators for Bacopa monniera (L.) Wettst., a traditional Indian medicinal plant, has been developed. Direct shoot bud regeneration was induced by culturing internode and leaf explants on Murashige and Skoog's (MS) medium supplemented with an antibiotic (trimethoprim) or a fungicide (bavistin). Bavistin showed a marked cytokinin-like activity, as evident from high number of shoot buds induced in node, internode and leaf explants. Optimum adventitious shoot buds induction occurred at 300 mg/l bavistin from internode explants. In vitro regenerated shoots were elongated and rooted before transferred to field with 85% survival. The regeneration protocol developed in this study illustrates the usefulness of additives for mass propagation and germplasm conservation of B. monniera.

Bacopa↗

PubMed2004

Shoot regeneration from GUS-transformed tomato (Lycopersicon esculentum) hairy root.

To study the influence of genetic background on the transformation and regeneration of cultivated tomato plants, hairy root lines of tomato (Lycopersicon esculentum) were obtained by inoculating the hypocotyl explants of three tomato cultivars with the Agrobacterium rhizogenes strain DCAR-2, which harbors the pBI-121 binary vector. The Ri-T-DNA transformation into the plant DNA was confirmed by both of mikimopine and GUS assay analyses. The regeneration efficiency from hairy root explants was assessed. The data indicated that white embryonic calli were formed within two weeks in the presence of 2 mgl(-1) 2, 4-D plus 0.25 mgl(-1) kinetin. Adventitious shoots emerged from the embryonic callus in the presence of 1 mgl(-1) GA3 along with 0.5 mgl(-1) NAA. The regeneration frequency was higher in the cultivar UC-97, followed by Momotaro and then Edkawi. Molecular confirmation of the integration of the GUS gene into the hairy root-derived plants genomes was done via PCR using GUS-specific primers and also using Southern blotting analysis. Our data shows that regeneration is possible from hairy roots of the cultivated tomato and this system could be used to produce transgenic tomato plants expressing the genes present in Agrobacterium rhizogenes binary vectors.

Adenine↗

PubMed2026

Development of an Efficient Regeneration and Agrobacterium-Mediated Transformation Protocol for Hosta 'Light Star' Using the RUBY Reporter Gene.

Hosta plantaginea is a perennial shade-tolerant herb of the Liliaceae family, with high ornamental and urban greening value. Hosta 'Light Star' is a newly developed ornamental cultivar with yellow-margined leaves and lilac flowers, but no efficient in vitro regeneration or genetic transformation system has been established for this cultivar to date. In this study, we established a highly efficient in vitro regeneration system for Hosta 'Light Star,' and developed an Agrobacterium-mediated genetic transformation protocol using the RUBY visual reporter gene for non-invasive screening of positive transformants. The optimal callus induction medium was MS + 2 mg/L 6-BA + 0.3 mg/L NAA + 0.05 mg/L 2, 4-D, with a callus induction rate of 53.33% for leaf explants (the optimal explant for sterile seedlings). The optimal adventitious bud proliferation medium was MS + 2 mg/L 6-BA + 0.1 mg/L NAA, with a proliferation coefficient of 5.87. The optimal rooting medium was 1/2 MS + 0.5 mg/L NAA + 0.5 mg/L IBA, with a 100% rooting rate. The optimal transplant substrate was perlite:vermiculite = 2:1, with a 100% transplant survival rate after acclimatization. For Agrobacterium-mediated transformation, the optimal infection parameters were as follows: Agrobacterium suspension OD600 = 0.6, infection time of 10 min, and 200 μM acetosyringone; the optimal selection conditions were 300 mg/L cefotaxime for bacteriostasis and 30 mg/L hygromycin for transformant screening. The final stable transformation efficiency was 2.50% (95% CI 1.23-3.77%), with an escape rate of 16.13%. Transgenic plants showed distinct purplish-red coloration in roots, stems, and leaves, with significantly higher betacyanin accumulation than wild-type plants (p < 0.05). Stable integration and expression of the RUBY gene were confirmed by PCR, RT-PCR, and RT-qPCR. This study establishes the first efficient regeneration and Agrobacterium-mediated transformation system for Hosta 'Light Star,' and validates the feasibility of the RUBY reporter gene as a visual marker for Hosta transformation. This system provides a solid technical platform for functional genomic studies, CRISPR/Cas9-mediated gene editing, and molecular breeding of ornamental traits in Hosta.

Transformation, Genetic↗