Biochemical changes in Pinus pinea seeds. II. The stimulation is isocitrate lyase and malate dehydrogenase activities by exogenous growth substances.

Treatment of intact pine seeds with plant hormones and steroid substances for several days, after an initial 24 hour immersion in different hormone solutions, resulted in a substantial increase in the specific activity of isocitrate lyase and malate dehydrogenase than the observed in the corresponding control solutions. Fresh weights did not show any increase, because water uptake was reduced in presence of plant hormones (indolacetic acid, kinetine and giberellic acid). However, dry weights were consistently greater than those of the control solutions.