What remains of the Cholodny-Went theory? Introduction.

The Cholodny-Went theory, which states that plant tropisms in roots and shoots are due to the unequal distribution of the growth regulator auxin in reponse to light or gravity, presented a simple and direct explanation of these phenomena. This was significant in the 1930s when simple explanations were lacking, and much research into this theory has been performed since that time. From the 1980s forward, there has been much questioning and controversy surrounding the theory. In this introduction to 15 brief articles, the author describes how leading scientists in the field were asked to air their opinions of the theory and formulate questions for each other. The resulting articles are presented in an attempt to stimulate discussion and give insights into the state of the Cholodny-Went theory in the 1990s.