Effect of Indole-3-Acetic Acid on Tensile Creep of Japanese Black Pine Hypocotyl

Abstract

Tensile creep experiments were employed to acertain the effect of indole-3-acetic acid (IAA) on the extensibility of the cell walls of woody plants. Hypocotyls of Japanese black pine in their rapid growth stage were used. It was determined that 10 ppm IAA changed the tensile creep process to the one which was difficult to elongate at later stage. It was also suggested that 10 ppm IAA increased the retarded elasticity and inhibited the flow which occurs under a small load without IAA. An other result was that the elongation of the living segment was sensitive to the load previously added to it.