Some Anatomical Effects of Kinetin and Red Light on Disks of Bean Leaves.

The application of kinetin (6-furfurylaminopurine) produces some effects similar to those induced by exposure to red light (Miller, 3, and Scott and Livermiian, 5). Both cause increased expansion of disks from bean leaves, greater elongation in stems and petioles of bean seedlings, and increased germination of lettuce seeds in the dark. Both treatments inhibit internodal elongation in excised peas. Because of the striking resemblance in these effects, Miller (3) suggested that these two treatments may operate through the same biological mechanism. A subsequent study of the germination of lettuce seeds in the dark indicated that kinetin is not involved directly in the photoreaction or in the reactions which immediately precede or follow it (Miller, 4). Scott and Liverman (5) also doubted if kinetin controlled the same reaction step as red light. The objective of the present investigation was to determine if anatomical differences occur between samples of disks from bean leaves treated with kinetin and those exposed to red light.