PARENT SESSION
Poster Session #53: Plant Competition.
Thursday, August 8. Presentation from 8:00 AM to 9:30 AM. Exhibit Hall B & C, TCC

Mechanism of action and ecophysiological role of a lichen anthraquinone analogue.

Aguilar, Deborah^*,1, Romagni, Joanne¹, ¹ University of St. Thomas, Houston, TX

ABSTRACT- Anthraquinones are a class of quinones characterized by three benzyl rings. Some of these, including emodin and rhodocladonic acid, are produced by secondary metabolism of lichens. These naturally occurring compounds probably play an important role in interspecific and intraspecific competition in lichens. We are attempting to discover a new mechanism of action for DNA 3-55-1, an analogue of the naturally occurring anthraquinone, emodin. While other research has shown that emodin is a casein kinase II inhibitor competitively inhibiteing the ATP binding site, our analogue appears to have a different mode of action. This analogue causes dose-dependent growth inhibition in both monocots (Agrostis tenuis) and dicots (e.g. Latuca sativa). It also causes significantly decreased inhibition of germination (> 50% at 100 M) and root malformation. In addition, the results of a mitotic index showed abnormal chromosomal separation, which can be seen in both metaphase and anaphase. Currently we are investigating the abnormal alignment of chromosomes to determine whether it is due to microtubule dysfunction or kinetochore dysfunction.

KEY WORDS: phytotoxins, anthraquinones, lichens