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J. Puonti-Kaerlas

Bio: J. Puonti-Kaerlas is an academic researcher from Uppsala University. The author has contributed to research in topics: Agrobacterium tumefaciens & Transformation (genetics). The author has an hindex of 2, co-authored 2 publications receiving 177 citations.

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Journal ArticleDOI
TL;DR: A transformation system that allows regeneration of transgenic pea plants from calli selected for antibiotic resistance was developed and the transformation of the calli and regenerated plants was confirmed by DNA analysis.
Abstract: A transformation system that allows regeneration of transgenic pea plants from calli selected for antibiotic resistance was developed. Explants from axenic shoot cultures and seedling epicotyls were cocultivated with nononcogenic Agrobacterium tumefaciens strains, and transformed callus could be selected on callus-inducing media containing either 15 mg/l hygromycin or 75 mg/l kanamycin. After several passages on regeneration medium, shoot organogenesis could be reproducibly induced on hygromycin-resistant calli, but not on the calli selected for kanamycin resistance. Regenerated shoots could subsequently be rooted and transferred into the greenhouse. In addition, the effects of different callus-inducing and growth media on organogenesis were investigated. The transformation of the calli and regenerated plants was confirmed by DNA analysis.

129 citations

Journal ArticleDOI
TL;DR: The transmission of the introduced gene into the progeny of the regenerated transgenic plants was studied over two generations, and stable transmission was shown to take place.
Abstract: An analysis of the progeny of primary transgenic pea plants in terms of transmission of the transferred DNA, fertility and morphology is presented. A transformation system developed for pea that allows the regeneration of fertile transgenic pea plants from calli selected for antibiotic resistance was used. Expiants from axenic shoot cultures were co-cultivated with a nononcogenic Agrobacterium tumefaciens strain carrying a gene encoding hygromycin phosphotransferase as selectable marker, and transformed callus could be selected on callus-inducing media containing 15 mg/l hygromycin. After several passages on regeneration medium, shoot organogenesis could be reproducibly induced on the hygromycin resistant calli, and the regenerated shoots could subsequently be rooted and transferred to the greenhouse, where they proceeded to flower and set seed. The transmission of the introduced gene into the progeny of the regenerated transgenic plants was studied over two generations, and stable transmission was shown to take place. The transgenic nature of the calli and regenerated plants and their progeny was confirmed by DNA and RNA analysis. The DNA and ploidy levels of the progeny plants and primary regenerants were studied by chromosome analysis, and the offspring of the primary transformants were evaluated morphologically.

51 citations


Cited by
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Journal ArticleDOI
TL;DR: The findings demonstrate the feasibility of using genetic engineering to improve the nutritive value of grain crops and give statistically significant increases in live weight gain, true protein digestibility, biological value, and net protein utilization in feeding trials with rats.
Abstract: With the aim of improving the nutritive value of an important grain legume crop, a chimeric gene specifying seed-specific expression of a sulfur-rich, sunflower seed albumin was stably transformed into narrow-leafed lupin (Lupinus angustifolius L.). Sunflower seed albumin accounted for 5% of extractable seed protein in a line containing a single tandem insertion of the transferred DNA. The transgenic seeds contained less sulfate and more total amino acid sulfur than the nontransgenic parent line. This was associated with a 94% increase in methionine content and a 12% reduction in cysteine content. There was no statistically significant change in other amino acids or in total nitrogen or total sulfur contents of the seeds. In feeding trials with rats, the transgenic seeds gave statistically significant increases in live weight gain, true protein digestibility, biological value, and net protein utilization, compared with wild-type seeds. These findings demonstrate the feasibility of using genetic engineering to improve the nutritive value of grain crops.

290 citations

Journal ArticleDOI
TL;DR: A reproducible transformation system was developed for pea using as explants sections from the embryonic axis of immature seeds, and transformed plants were resistant to the herbicide Basta when sprayed at rates used in field practice.
Abstract: A reproducible transformation system was developed for pea (Pisum sativum L.) using as explants sections from the embryonic axis of immature seeds. A construct containing two chimeric genes, nopaline synthase-phosphinothricin acetyl transferase (bar) and cauliflower mosaic virus 35S-neomycin phosphotransferase (nptII), was introduced into two pea cultivars using Agrobacterium tumefaciens-mediated transformation procedures. Regeneration was via organogenesis, and transformed plants were selected on medium containing 15 mg/L of phosphinothricin. Transgenic peas were raised in the glasshouse to produce flowers and viable seeds. The bar and nptII genes were expressed in both the primary transgenic pea plants and in the next generation progeny, in which they showed a typical 3:1 Mendelian inheritance pattern. Transformation of regenerated plants was confirmed by assays for neomycin phosphotransferase and phosphinothricin acetyl transferase activity and by northern blot analyses. Transformed plants were resistant to the herbicide Basta when sprayed at rates used in field practice.

253 citations

Journal ArticleDOI
TL;DR: It is concluded that the spread of modified crops and their hybrids with wild relatives can be modelled in the same manner as for unmodified crops.
Abstract: It has been suggested that genetic modification could lead to crops with enhanced invasiveness and persistence. These new genotypes could invade natural ecosystems and cause undesirable change, either through spread of the crops themselves or through hybridization with wild relatives. We review the progress made in the genetic modification of the major UK crops, and identify those crops and traits in which genetic modification is most advanced. Data on the potential for the spread of transgenes through pollen movement and the relative performance of modified and unmodified crops are examined. It is concluded that the spread of modified crops and their hybrids with wild relatives can be modelled in the same manner as for unmodified crops (...)

244 citations

Journal ArticleDOI
TL;DR: A method for regenerating stably transformed cassava plants after cocultivation with Agrobacterium tumefaciens is reported, which opens cassava for future improvement via biotechnology.
Abstract: Genetic engineering can be used to complement traditional breeding methods in crop plant improvement. Transfer of genes from heterologous species provides the means of selectively introducing new traits into crop plants and expanding the gene pool beyond what has been available to traditional breeding systems. The prerequisites for genetic engineering are efficient transformation and tissue culture systems that allow selection and regeneration of transgenic plants. Cassava, an integral plant for food security in developing countries, has until now been recalcitrant to transformation approaches. We report here a method for regenerating stably transformed cassava plants after cocultivation with Agrobacterium tumefaciens, which opens cassava for future improvement via biotechnology.

179 citations

Journal ArticleDOI
TL;DR: P Puget seeds were used to develop a reproducible Agrobacterium tumefaciens-mediated transformation system that facilitates the rapid generation of phenotypically normal, self-fertile plants containing functional transgenes inherited in a Mendelian fashion.
Abstract: The lateral cotyledonary meristems of germinatingPisum sativum cv. Puget seeds were used to develop a reproducibleAgrobacterium tumefaciens-mediated transformation system. This procedure exhibits distinct advantages over those previously reported, in that it uses dry seed as starting material, and the highly regenerable cotyledonary meristems rapidly produce transgenic shoots without an intermediate callus phase. This transformation regime facilitates the rapid generation of phenotypically normal, self-fertile plants containing functional transgenes inherited in a Mendelian fashion.

141 citations