Valerie Sponsel, Ph.D., D.Sc.
Areas of Specialization
- medicinal plants
- plant growth and development
- plant hormones
Ph.D.; University of Wales, U.K.
D.Sc.; University of Bristol, U.K.
Dr. Sponsel’s research focuses on the gibberellin class of plant hormones that regulates plant growth and development. Many different gibberellins have been identified in plants and in the fungus Gibberella fujikuroi. It was the original identification of these compounds in Gibberella that led to their unusual name. In plants, one class of hormone can control many different processes; for example, gibberellins regulate seed germination, stem growth, transition to flowering, and fruit development. In most instances this regulation involves interaction of gibberellins with other hormones.
Currently, the lab is interested in cross-talk between gibberellins and two other types of plant hormones, auxin and jasmonic acid in the model plant Arabidopsis thaliana. Defining processes and mechanisms of how growth and development are regulated in Arabidopsis can provide information that can be useful to improve growth and productivity of crop plants.
Dr. Sponsel also has a long-standing interest in medicinal plants and is currently collaborating with Dr. Francis Yoshimoto in UTSA’s Chemistry Department on a project to elucidate the final steps in biosynthesis of artemisinin in the plant Artemisia annua. Artemisinin is a potent drug for treating malaria.
Students in the lab use a variety of Arabidopsis mutants in which the biosynthesis, transport, signaling, or response of one hormone is perturbed to examine the effects of other hormones on the transcription of genes involved in hormone action. Plants are grown under sterile conditions and/or in environmental growth chambers prior to nucleic acid extraction and PCR. Expression of reporter genes is monitored histochemically and by confocal microscopy.
Click here for a list of publications.