Interaction of indole-3-acetic acid with Avena sativa leaf-sheath pulvini during the gravitropic response

Changes in auxin-sensitivity of Avena sativa (oat) leaf-sheath pulvini during the gravitropic response were studied. The biphasic dose-response curves for IAA induced tissue elongation show that the lower and upper sides of gravistimulated oat shoot pulvini show maximum elongation at 10;The in vitro activation of the plasma membrane-localized H;The IAA-induced activation of the H;Based on results obtained in this study, a hypothesis is put forward which says that during the gravitropic response, oat shoot pulvini change their auxin-sensitivity by a modification of a 34 kD soluble ABP, whose cellular function is the activation of the plasma membrane associated H...