Other areas of research

The utility of GUS and GFP

Green fluorescent protein has been an important advance in marker protein technology. In previously published work from the plant molecular biology community, strong constitutive promoters have been used to drive GFP expression and to generate brightly glowing plants. We have found that standard GFP is less valuable with weaker promoters mainly due to the high autofluorescence in Arabidopsis that obscures the GFP signal.

We directly compared the ability to detect GUS and the ability to detect GFP by crossing two independent lines carrying the two different transgenes, to compare the expression of both plant genes in a single plant. Northern analysis shows that differences in detection could not be attributed to differences in transgene transcription.

Mantis J and BW Tague. (2000) Comparing the utility of ß-glucuronidase and green fluorescent protein for detection of weak promoter activity in Arabidopsis thaliana. Plant Molecular Biology Reporter 18:319-330.

A new selectable marker for Arabidopsis thaliana

Syngenta (Research Triangle Park, NC) has developed a new selectable marker for use in plants that is not based on herbicide or antibiotic resistance. The phosphomannose isomerase (PMI) gene confers resistance to mannose which inhibits the growth and germination of a number of plant species at concentrations as low as 1 mM.

My lab has shown that PMI can be used as a marker during the germ-line transformation of Arabidopsis thaliana. This work represents a significant addition to the tools used in Arabidopsis research. This is an extremely inexpensive selectable agent, as compared to herbicides and antibiotics. Unlike most selectable markers, it can be used in both sterile culture (petri dishes) and in non-sterile conditions (soil).

Todd R and Tague, BW. (2001) Phosphomannose isomerase, a versatile selectable marker for Arabidopsis thaliana transformation. Plant Molecular
Biology Reporter. 19: 307-319

Transformation of additional species by germ-line transformation

The next important step in plant molecular genetics will be to export lessons and techniques learned from Arabidopsis into other plant species. A significant advance in Arabidopsis research has been germ-line transformation. In this procedure, floral buds of soil-grown plants are dipped in Agrobacterium tumefaciens carrying the transgene of interest. The plants are then allowed to set seed. About 2-5% of the resulting seed carry the transgene. All steps of transformation can now be done in non-sterile conditions, making it easy to introduce transgenic plant production into the undergraduate laboratory.

The ability to transform plants without plant regeneration may open up the number of plants that are transformable. It is unclear, however, just how widely applicable this procedure will be. Published reports of successes are few. We have succeeded in the germ line molecular transformation of Arabidopsis lasiocarpa with a GFP construct. Integrative transformation has been confirmed at the molecular level.

Tague, BW. (2001) Germ-line transformation of Arabidopsis lasiocarpa. Transgenic Research. 10: 259-267

Flavonoids and auxin

The Tague lab has spread the Arabidopsis gospel at WFU, introducing Arabidopsis thaliana to the Muday lab through the training of undergraduate and graduate students. The use of Arabidopsis mutants with lesions in flavonoid biosynthesis has led to some interesting work on the role of flavonoids in regulating auxin transport.

Peer, WA, AS Murphy, DE Brown, BW Tague, GK Muday and L Taiz. (2001) Flavonol precursor accumulation patterns correlate with developmental phenotypes of transparent testa mutants of Arabidopsis thaliana. Plant Physiology 126:524-535

Brown DE, AM Rashotte, AS Murphy, BW Tague, WA Peer, L Taiz, and GK Muday. (2001) Flavonoids act as negative regulators of auxin transport in vivo in Arabidopsis thaliana. Plant Physiology 126: 536-548