Paul J. J. Hooykaas

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Arabidopsis pinoid mutants show a strong phenotypic resemblance to the pin-formed mutant that is disrupted in polar auxin transport. The PINOID gene was recently cloned and found to encode a protein-serine/threonine kinase. Here we show that the PINOID gene is inducible by auxin and that the protein kinase is present in the primordia of cotyledons, leaves(More)
Agrobacterium tumefaciens transfers part of its tumour-inducing (Ti) plasmid, the transferred or T-DNA, to plants during tumourigenesis. This represents the only example of naturally occurring trans-kingdom transfer of genetic material. Here we report that A.tumefaciens can transfer its T-DNA not only to plant cells, but also to another eukaryote, namely(More)
Mutations in ribosomal protein (RP) genes in Drosophila lead to strong developmental phenotypes, expressed in the semi-dominant Minute syndrome. In plants, however, mutations in RP genes have so far only been reported to result in recessive developmental phenotypes. We present the analysis of an Arabidopsis promoter-trap line, in which a T-DNA insertion in(More)
Agrobacterium tumefaciens transfers part of its Ti plasmid, the T-DNA, to plant cells during tumorigenesis. It is routinely used for the genetic modification of a wide range of plant species. We report that A. tumefaciens can also transfer its T-DNA efficiently to the filamentous fungus Aspergillus awamori, demonstrating DNA transfer between a prokaryote(More)
In this study Agrobacterium tumefaciens transferred DNA (T-DNA) was targeted to a chromosomally introduced lox site in Arabidopsis thaliana by employing the Cre recombinase system. To this end, Arabidopsis target lines were constructed which harboured an active chimeric promoter-lox-cre gene stably integrated in the plant genome. A T-DNA vector with a(More)
The nine decades since Smith and Townsend demonstrated that Agrobacterium tumefaciens causes plant tumors (95) have been marked by a series of surprises. Among the most important of these was the report in 1958 that these tumors could be excised and propagated in vitro without exogenous plant hormones (7). Equally important were a series of reports(More)
The Agrobacterium VirB/D4 transport system mediates the transfer of a nucleoprotein T complex into plant cells, leading to crown gall disease. In addition, several Virulence proteins must somehow be transported to fulfill a function in planta. Here, we used fusions between Cre recombinase and VirE2 or VirF to directly demonstrate protein translocation into(More)
We determined whether T-DNA molecules introduced into plant cells using Agrobacterium are suitable substrates for homologous recombination. For the detection of such recombination events different mutant versions of a NPTII construct were used. In a first set of experiments protoplasts of Nicotiana tabacum SR1 were cocultivated with two Agrobacterium(More)
Ti plasmid mutants derived from Agrobacterium tumefaciens strain Ach5 that induce tumors of abnormal morphology have been analyzed. On tobacco, A. tumefaciens mutant strain LBA4060 induces tumors that specifically give rise to shoots. Shoots continue to grow from in vitro cultured bacteria-free tumor tissue derived from such tumors. The mutant character is(More)