Microinjection Technique: Routine System for Characterization of Microcapillaries by Bubble Pressure Measurement

Schnorf, Martin; Potrykus, Ingo; Neuhaus, Gunther

doi:10.1006/excr.1994.1038

Cited by 41 publications

(27 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Injection capillaries were pulled from borosilicate glass (Hilgenberg, Malsfeld, Germany) using a purpose-built puller (Getra, MuÈ nchen, Germany) with a heating ®lament made of three loops of a platinum-iridium wire. Capillaries with an inner diameter of 0.2±0.3 lm (estimated as described by Schnorf et al 1994) were used. Acropetal injections (Fig.…”

Section: Methodsmentioning

confidence: 99%

Microinjection of heme oxygenase genes rescues phytochrome-chromophore-deficient mutants of the moss Ceratodon purpureus

Brücker

Zeidler

Kohchi

et al. 2000

Planta

View full text Add to dashboard Cite

In protonemal tip cells of the moss Ceratodon purpureus (Hedw.) Brid., phototropism and chlorophyll accumulation are regulated by the photoreceptor phytochrome. The mutant ptr116 lacks both responses as a result of a defect in the biosynthesis of phytochromobilin, the chromophore of phytochrome, at the point of biliverdin formation. The rescue of the phototropic response and of chlorophyll synthesis were tested by injecting different substances into tip cells of ptr116. Microinjection was first optimised with the use of fluorescent dyes and an expression plasmid containing a green fluorescent protein (GFP) gene. Injected phycocyanobilin, which substitutes for phytochromobilin, rescued both the phototropic response and light-induced chlorophyll accumulation in ptr116. The same results were obtained when expression plasmids with heme oxygenase genes of rat (HO-1) and Arabidopsis thaliana (L.) Heynh. (HY1) were injected. Heme oxygenase catalyses the conversion of heme into biliverdin. Whereas HY1 has a plastid target sequence and is presumably transferred to plastids, HO-1 is proposed to be cytosolic. The data show that ptr116 lacks heme oxygenase enzyme activity and indicate that heme oxygenases of various origin are active in Ceratodon bilin synthesis. In addition, it can be inferred from the data that the intracellular localisation of the expressed heme oxygenase is not important since the plastid enzyme can be replaced by a cytosolic one.

show abstract

Section: Methodsmentioning

confidence: 99%

Microinjection of heme oxygenase genes rescues phytochrome-chromophore-deficient mutants of the moss Ceratodon purpureus

Brücker

Zeidler

Kohchi

et al. 2000

Planta

View full text Add to dashboard Cite

show abstract

“…Micropipettes were prepared from 100-mm-long borosilicate glass (outer diameter, 1.5 mm; inner diameter, 0.87 mm; omega dot, 0.2 mm; Hilgenberg, Malsfeld, Germany) by using a vertical pipette puller with a solenoid-type heating filament made of platinum wire according to the manufacturer's instructions (Sutter P30; Bachofer, Reutlingen, Germany) and were examined under the microscope for appropriate shape and tip diameter (10). Micropipettes with a tip diameter of approximately 0.5 m were filled with solutions containing Pep-25 and fluorescein isothiocyanate-dextran 10,000 or Lucifer yellow (final concentrations 2.5 mg͞ml and 0.2 mg͞ml, respectively) for visualization of pipette contents under the epifluorescence microscope and connected to a microinjector (Transjector 5246 basic; Eppendorf).…”

Section: Methodsmentioning

confidence: 99%

Local mechanical stimulation induces components of the pathogen defense response in parsley

Gus-Mayer¹,

Naton²,

Hahlbrock³

et al. 1998

Proc. Natl. Acad. Sci. U.S.A.

112

View full text Add to dashboard Cite

Cell suspension cultures of parsley (Petroselinum crispum) have previously been used as a suitable system for studies of the nonhost resistance response to Phytophthora sojae. In this study, we replaced the penetrating fungus by local mechanical stimulation by using a needle of the same diameter as a fungal hypha, by local application of a structurally defined fungus-derived elicitor, or by a combination of the two stimuli. Similar to the fungal infection hypha, the local mechanical stimulus alone induced the translocation of cytoplasm and nucleus to the site of stimulation, the generation of intracellular reactive oxygen intermediates (ROI), and the expression of some, but not all, elicitor-responsive genes. When the elicitor was applied locally to the cell surface without mechanical stimulation, intracellular ROI also accumulated rapidly, but morphological changes were not detected. A combination of the mechanical stimulus with simultaneous application of low doses of elicitor closely simulated early reactions to fungal infection, including cytoplasmic aggregation, nuclear migration, and ROI accumulation. By contrast, cytoplasmic rearrangements were impaired at high elicitor concentrations. Neither papilla formation nor hypersensitive cell death occurred under the conditions tested. These results suggest that mechanical stimulation by the invading fungus is responsible for the observed intracellular rearrangements and may trigger some of the previously demonstrated changes in the activity of elicitor-responsive genes, whereas chemical stimulation is required for additional biochemical processes. As yet unidentified signals may be involved in papilla formation and hypersensitive cell death.

show abstract

“…He left for a group leader position at the International Rice Research Institute (IRRI) in the Philippines, became a full professor in Calcutta, and is now a deputy director general (crop science) in the Indian Council of Agricultural Research. Gunther Neuhaus optimized microinjection for transformation of precursor cells of somatic embryos (40,41,48,85,86), moved to a full professor position at the University of Freiburg, and is currently the vice rector for research there. German Spangenberg, a fresh PhD when he joined, was so impressive that I promoted him early on to develop his own group, and within a few years he became the world leader in forage grass biotechnology (54, 89-91, 92, 94, 101, 102); since the mid-1990s, he has been a full professor in Melbourne, Australia.…”

Section: From a Group Leader To A Professor With Junior Groupsmentioning

confidence: 99%

From the Concept of Totipotency to Biofortified Cereals

Potrykus

2015

Annu. Rev. Plant Biol.

Self Cite

View full text Add to dashboard Cite

I was a college teacher when opportunity opened a path into academia. A fascination with totipotency channeled me into research on tissue culture. As I was more interested in contributions to food security than in scientific novelty, I turned my attention to the development of genetic modification technology for cereals. From my cell culture experience, I had reasons not to trust Agrobacterium for that purpose, and I developed direct gene transfer instead. In the early 1990s, I became aware of the problem of micronutrient deficiency, particularly vitamin A deficiency in rice-eating populations. Golden Rice, which contains increased amounts of provitamin A, was probably instrumental for the concept of biofortification to take off. I realized that this rice would remain an academic exercise if product development and product registration were not addressed, and this is what I focused on after my retirement. Although progress is slowly being made, had I known what this pursuit would entail, perhaps I would not have started. Hopefully Golden Rice will reach the needy during my lifetime.

show abstract

Microinjection Technique: Routine System for Characterization of Microcapillaries by Bubble Pressure Measurement

Cited by 41 publications

References 0 publications

Microinjection of heme oxygenase genes rescues phytochrome-chromophore-deficient mutants of the moss Ceratodon purpureus

Microinjection of heme oxygenase genes rescues phytochrome-chromophore-deficient mutants of the moss Ceratodon purpureus

Local mechanical stimulation induces components of the pathogen defense response in parsley

From the Concept of Totipotency to Biofortified Cereals

Contact Info

Product

Resources

About