Showing papers on "Arabidopsis published in 1987"

Acetosyringone promotes high efficiency transformation of Arabidopsis thaliana explants by Agrobacterium tumefaciens.

Abstract: High frequency transformation of Arabidopsis thaliana leaf explants has been obtained using a disarmed Ti plasmid containing the coding region of a neomycin phosphotransferase gene (NPT II) as a selectable marker. The rate of transformation ranged from 55 to 63 percent when acetosyringone (AS), a natural wound response molecule, was added to an Agrobacterium tumefaciens culture prior to incubation with leaf segments. Without acetosyringone, the transformation rate was approximately 2 to 3 percent. Calli resistant to G418 were regenerated into mature flowering plants in the presence of 10 μg/ml G418. Southern analysis and neomycin phosphotransferase assays confirmed the insertion and expression of the NPT II gene in regenerated Arabidopsis plants.

Studies on the introduction and mobility of the maize Activator element in Arabidopsis thaliana and Daucus carota.

Abstract: We have co-transformed carrot (Daucus carota) and Arabidopsis thaliana with an Agrobacterium tumefaciens non-tumorigenic T-DNA carrying the maize transposable element Activator (Ac) and an Agrobacterium rhizogenes Ri T-DNA. We present evidence that the Ac element transposes in transformed root or root-derived callus cultures of both species. We show that fertile plants can be regenerated from transformed, root-derived callus cultures of Arabidopsis, demonstrating the utility of the Ri plasmid for introducing the maize Ac element into plants. We also present evidence that Ac elements that excise from the transforming T-DNA early after transformation continue to be mobile in carrot root cultures.

Cloning of an Arabidopsis thaliana gene encoding 5-enolpyruvylshikimate-3-phosphate synthase: sequence analysis and manipulation to obtain glyphosate-tolerant plants.

Abstract: 5-enolpyruvylshikimate-3-phosphate synthase (EPSPs), the target of the herbicide glyphosate, catalyzes an essential step in the shikimate pathway common to aromatic amino acid biosynthesis. We have cloned an EPSP synthase gene from Arabidopsis thaliana by hybridization with a petunia cDNA probe. The Arabidopsis gene is highly homologous to the petunia gene within the mature enzyme but is only 23% homologous in the chloroplast transit peptide portion. The Arabidopsis gene contains seven introns in exactly the same positions as those in the petunia gene. The introns are, however, significantly smaller in the Arabidopsis gene. This reduction accounts for the significantly smaller size of the gene as compared to the petunia gene. We have fused the gene to the cauliflower mosaic virus 35 S promoter and reintroduced the chimeric gene into Arabidopsis. The resultant overproduction of EPSPs leads to glyphosate tolerance in transformed callus and plants.

The relatively large beta-tubulin gene family of Arabidopsis contains a member with an unusual transcribed 5' noncoding sequence

Abstract: We have characterized the beta-tubulin gene family of Arabidopsis thaliana. Five distinct genes were cloned and analyzed by restriction enzyme mapping and cross-hybridization studies. Three of the genes appear to be dispersed, whereas two others are linked within 1.5 kb of one another. The two linked genes are closely related and appear to have resulted from a fairly recent duplication. The three dispersed genes do not cross-hybridize to one another or to the two linked genes under highly stringent hybridization conditions, suggesting that they arose from more ancient duplications. From Southern analysis we estimate that there are a total of between six and ten beta-tubulin genes in Arabidopsis. Additional analyses indicate that the gene family is equal in size or larger than those in other plants, but significantly smaller than those in related Brassica species. Sequence determination of one of the Arabidopsis genes revealed a highly unusual transcribed leader sequence. The leader contains two fairly long tracks of adenines. One is located toward the 5′ end of the mRNA and the other is just before the initiation codon. A track of uridines is located between the adenine tracks. This leader can form two different secondary structures that may have regulatory significance.

Arabidopsis Thaliana: A Model System for Plant Molecular Biology

Abstract: Arabidopsis thaliana is a small member of the mustard family, botanical information on which dates back to the 16th century. It has many advantages as a model system for plant molecular genetics, such as a short life cycle, small size, small genome size, and well developed classical genetics. Arabidopsis thus provides an alternative system to the commonly used crop plants for studies in the molecular genetics of plant physiology and development.

Mutants of Arabidopsis Deficient in Fatty Acid Desaturation

Abstract: The isolation of a series of mutants with defects in lipid metabolism was originally motivated by the concept that, in order to study the functional significance of lipid unsaturation, it would be very useful to have a collection of otherwise isogenic mutant lines which differ only with respect to the activity of specific desaturases. We chose the small crucifer Arabidopsis thaliana (L.) as the experimental organism because it has a number of traits which render it particularly well-suited for physiological genetics (Estelle and Somerville 1986).