Mode of action of gibberellic Acid and light on lettuce seed germination.

The seeds of lettuce (Lactuca sativa L. cv. Grand Rapids) germinate in darkness at 25 C when treated by gibberellic acid (GA(3)) for 1 hour following 2 hours of imbibition.

The role of lipases in the germination of dormant apple embryos.

Changes in the activity of alkaline and acid lipases were studied during the culture of embryos isolated from dormant apple (Pyrus malus L.) seeds. Light and treatment with gibberellins (GAs) and with AMO-1618, an inhibitor of GA biosynthesis, influenced the activity of both enzymes.

Reinvestigation of apple-seed gibberellins.

Re-investigation of the gibberellins in apple seed has established the presence of GA4 and GA7 and of traces of GA9. The fraction, previously considered to be GA7 by TLC, contains small amounts of GA4 and traces of GA9; and the fraction, characterized as GA4 by TLC, contains traces of GA7 and GA9. However the present results do not change the previous conclusions that during the stratification of apple seed the level of GA7 remains fairly constant while that of GA4 increases.