Thale cress may be the only plant on Earth known more widely by its scientific name, Arabidopsis thaliana , than its common name.
The diminutive and delicate plant has become plant biology's workhorse, science's most widely used model organism for basic research in plant cell and molecular biology.
Indiana University Bloomington plant biologist Mark Estelle is among the scientists who have helped make Arabidopsis an attractive candidate for research in molecular biology, genetics, and biochemistry. Not all of his former students study Arabidopsis in their junior researcher careers, but many do.
Arabidopsis became a favorable organism for basic research because it reproduces quickly, has a relatively small genome, and is physically small -- thousands of plants can be grown simultaneously even in a small greenhouse.
Scientists' relationship with Arabidopsis has been remarkably fruitful. Estelle, for one, has used Arabidopsis to discover fundamental things about plants, such as how hormones induce growth and other changes.
Since joining IU in 1986, Estelle's research has uncovered numerous details of a previously unknown regulatory system for hormone action. Recently, his lab identified the receptor that binds the plant hormone auxin. The receptor was the missing link in the chain of events that controls plant growth and and development. His group has also shown that the molecular mechanism by which this receptor works is unlike any previously described. Moreover, the regulatory mechanisms he discovered in plants revealed the existence of fundamental shared regulatory pathways in plants and animals, including humans.
Colleagues praise Estelle's unflinching commitment to a variety of research questions over the course of his career as a plant biologist, which began at Michigan State University in 1983. Although Estelle has undertaken numerous projects, most have centered on how, exactly, plant hormones influence the expression of genes.
"Certainly the discovery of the auxin receptor, which had been a holy grail of plant physiology for ages, has been one of the climaxes of his work," said IUB plant biologist Roger Hangarter.
Another IUB plant biologist, Roger Innes, concurs. "Mark's career is a beautiful example of a scientist following one thread of research no matter the obstacle. He started out purely as a geneticist, isolating genes. But to answer some of the questions he faced, he really had to become a biochemist, so he retooled. He is astute and talented enough to master more than one field of science."
