Gibberellic acid and the fine structure of barley aleurone cells : I. Changes during the lag-phase of α-amylase synthesis.

This paper describes changes in the fine structure of barley aleurone cells following treatment with gibberellic acid (GA3). Within 2 hr of GA3 treatment the aleurone grains lose the spherical appearance characteristic of aleurone cells incubated in water and buffer alone. This swelling increases with increased exposure of the cells to GA3 and reaches a maximum at about 10 hr. Accompanying this increase in volume of the aleurone grains is an increase in the amount of rough endoplasmic reticulum. The relevance of these GA3-stimulated changes in aleurone-cell fine-structure to GA3-regulated α-amylase production is discussed.