title: Effect of red light on geotropism in pea epicotyls.
abstract: Dose response curves were determined for phytochrome phototransformation and for a phytochrome-controlled decrease in geotropic curvature in epicotyls of dark-grown Pisum sativum L. cv. Alaska. Ten times as much light was required to produce a spectrophotometrically detectable transformation of phytochrome as was required to produce a significant change in the geotropic response. The red light energy required for a 50% phytochrome transformation caused a 90% change in the physiological response.
authors: Department of Biological Sciences, Florida International University, Miami, Florida 33199.
authors: J A
authors: JA
authors: McArthur