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Tage Eriksson

Bio: Tage Eriksson is an academic researcher from Uppsala University. The author has contributed to research in topics: Protoplast & Callus. The author has an hindex of 34, co-authored 78 publications receiving 3558 citations.


Papers
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Journal ArticleDOI
TL;DR: Embryos of Picea abies at various developmental stages were cultured on defined media supplemented with 2,4-dichlorophenoxyacetic acid and N6-benzyladenine and contained polarized and organized structures (somatic embryos) which closely resembled the early stages of normal zygotic embryogeny.

339 citations

Journal ArticleDOI
01 May 1981-Botany
TL;DR: Isolated embryos of Pinus contorta Dougl.
Abstract: Isolated embryos of Pinus contorta Dougl. ex Loud, were induced to form adventitious buds on a cytokinin-supplemented medium. Further development of the buds required transfer to a cytokininless medium. Both bud induction and development were stimulated by a dilution of the basal culture medium and best growth was obtained if the buds were isolated from the original tissue when stem elongation had started. The growth of these isolated adventitious shoots was further stimulated by adding activated charcoal to the diluted medium. A small percentage of the shoots have been rooted. The capacity for bud formation varied among seeds collected from different regions of British Columbia. This method for induction of adventitious buds on embryos was also applicable to explants of young seedlings.

318 citations

Journal ArticleDOI
TL;DR: It was shown by mass spectrometry that the media without charcoal contained high amounts of phenylacetic acid and p-OH-benzoic acid (Daucus, Allium, and Haplopappus), whereas the media with activated charcoal did not.
Abstract: Cell suspensions of Daucus carota and Haplopappus gracilis and callus suspensions of Allum cepa var. proliferum were grown in media with and without activated charcoal. Differentiation occurred in those Daucus and Allium cultures that contained charcoal. It was shown by mass spectrometry that the media without charcoal contained high amounts of phenylacetic acid and p-OH-benzoic acid (Daucus), 2,6-OH-benzoic acid (Allium) and benzoic acid, pelargonic acid and caprylic acid (Haplopappus), whereas the media with activated charcoal did not. It was also shown that p-OH-benzoic acid had inhibitory effects on the embryogenesis in Daucus cultures.

259 citations

Journal ArticleDOI
TL;DR: Light- and electron micrographs show the strong adhesion and fusion of cell membranes and the osmotic changes in the protoplasts induced by polytehylene glycol.

133 citations


Cited by
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Journal ArticleDOI
TL;DR: The nutrient requirements of suspension cultures from soybean root have been investigated, and a simple medium consisting of mineral salts, sucrose, vitamins and 2,4-dichlorophenoxyacetic acid (2, 4- d) has been designed.

9,342 citations

Journal ArticleDOI
TL;DR: A review of the literature reveals a significant number of early studies on biochar-type materials as soil amendments either for managing pathogens, as inoculant carriers or for manipulative experiments to sorb signaling compounds or toxins as mentioned in this paper.
Abstract: Soil amendment with biochar is evaluated globally as a means to improve soil fertility and to mitigate climate change. However, the effects of biochar on soil biota have received much less attention than its effects on soil chemical properties. A review of the literature reveals a significant number of early studies on biochar-type materials as soil amendments either for managing pathogens, as inoculant carriers or for manipulative experiments to sorb signaling compounds or toxins. However, no studies exist in the soil biologyliterature that recognize the observed largevariations ofbiochar physico-chemical properties. This shortcoming has hampered insight into mechanisms by which biochar influences soil microorganisms, fauna and plant roots. Additional factors limiting meaningful interpretation of many datasets are the clearly demonstrated sorption properties that interfere with standard extraction procedures for soil microbial biomass or enzyme assays, and the confounding effects of varying amounts of minerals. In most studies, microbial biomass has been found to increase as a result of biochar additions, with significant changes in microbial community composition and enzyme activities that may explain biogeochemical effects of biochar on element cycles, plant pathogens, and crop growth. Yet, very little is known about the mechanisms through which biochar affects microbial abundance and community composition. The effects of biochar on soil fauna are even less understood than its effects on microorganisms, apart from several notable studies on earthworms. It is clear, however, that sorption phenomena, pH and physical properties of biochars such as pore structure, surface area and mineral matter play important roles in determining how different biochars affect soil biota. Observations on microbial dynamics lead to the conclusion of a possible improved resource use due to co-location of various resources in and around biochars. Sorption and therebyinactivation of growth-inhibiting substances likelyplaysa rolefor increased abundance of soil biota. No evidence exists so far for direct negative effects of biochars on plant roots. Occasionally observed decreases in abundance of mycorrhizal fungi are likely caused by concomitant increases in nutrient availability,reducing theneedfor symbionts.Inthe shortterm,therelease ofavarietyoforganic molecules from fresh biochar may in some cases be responsible for increases or decreases in abundance and activity of soil biota. A road map for future biochar research must include a systematic appreciation of different biochar-types and basic manipulative experiments that unambiguously identify the interactions between biochar and soil biota.

3,612 citations

Journal ArticleDOI
TL;DR: The construction of new helper Ti plasmids for Agrobacterium-mediated plant transformation using T-DNA regions deleted using site-directed mutagenesis to yield replicons carrying thevir genes that will complement binary vectorsin trans.
Abstract: We describe the construction of new helper Ti plasmids forAgrobacterium-mediated plant transformation. These plasmids are derived from three differentAgrobacterium tumefaciens Ti plasmids, the octopine plasmid pTiB6, the nopaline plasmid pTiC58, and the L,L-succinamopine plasmid pTiBo542. The T-DNA regions of these plasmids were deleted using site-directed mutagenesis to yield replicons carrying thevir genes that will complement binary vectorsin trans. Data are included that demonstrate strain utility. The advantages ofAgrobacterium strains harbouring these ‘disamed’ Ti plasmids for plant transformation viaAgrobacterium are discussed.

1,360 citations

Book ChapterDOI
TL;DR: The preparation of protoplasts from TBY-2 cells, from which the isolation of organelles is easy, has been established and using the synchrony system, the change in the cell cycle progression of TBY -2 cells successfully followed thechange in cytoskeletons.
Abstract: Publisher Summary This chapter highlights tobacco BY-2 (TBY-2) cell line. TBY-2 derived from the seedlings of N. tabacum L. cv. Bright Yellow 2 grows fast and multiplies 80- to 100-fold in 1 week. After the stationary phase, cells of TBY-2 are transferred to a medium containing aphidicolin for 24 hr and then released from treatment; high synchrony is obtained starting from the S phase. TBY-2 cells are propagated in the modified medium of Linsmaier and Skoog, in which KH2PO4 and thiamine HCl are increased to 370 and 1 mg/liter, respectively, and sucrose and 2,4-D are supplemented to 3% and 0.2 mg/liter, respectively. The preparation of protoplasts from TBY-2 cells, from which the isolation of organelles is easy, has been established. Using the synchrony system, the change in the cell cycle progression of TBY-2 cells successfully followed the change in cytoskeletons. Biochemical and molecular biological studies can also be done on TBY-2 cells, as mass culture of this material is readily feasible.

1,183 citations

Book ChapterDOI
TL;DR: The variation in the response of different organs to the carcinogenic nitroso compounds is of interest in relation to the biochemical changes that may be essential for the initiation of a carcinogenic change.
Abstract: Publisher Summary This chapter provides an overview of some of the relevant chemistry (general chemistry, preparation methods, and analytical methods) of the nitroso carcinogenic compounds and discusses the pathological lesions induced by these compounds and their mutagenic activity. Experimental studies on compounds like dimethylnitrosamine showed that they cause liver necrosis in rats, accompanied by hemorrhages into the liver and lungs and frequently an associated hemorrhagic ascites and blood in the lumen of the gut. Acute toxicity of other dialkyl and related nitrosamines cause liver damage, hemorrhagic lung lesions, convulsions, and coma. The neoplastic changes in the body organs (live, kidney, bladder, nose and nasal sinuses, lungs and bronchi, alimentary canal, nervous system, and skin) and the development of the malignant lesion caused by carcinogenic nitroso compounds are also illustrated in the chapter with the help of animal models. The variation in the response of different organs to the carcinogenic nitroso compounds is of interest in relation to the biochemical changes that may be essential for the initiation of a carcinogenic change. Many carcinogenic nitroso compounds are mutagenic. The nitroso mutagens act by the alkylation of the genetic material. The chapter also discusses the metabolism of nitroso carcinogens both in vivo and in vitro, along with their biochemical effects. The induction of cancers by single doses of rapidly eliminated nitroso carcinogens implies an interaction between the carcinogen and/or a product of its decomposition with some component or components of the cells, which must occur within a short time after administration. The nature of the proximate carcinogen and some of its possible interactions with cellular components and some serious carcinogenic hazards caused by the nitroso compounds are also discussed in the chapter.

1,060 citations