Abstract: | This paper deals with the experimental results of the effect of trypsin on the vernalization process in the winter wheat. The variations of both the trypsin-like enzyme activity and the soluble protein content during vernalization in winter wheat seedlings were assayed. The results are as follows: 1. When the vernalization was progressing to the middle stage (around 25 days), the seedlings of the winter wheat were moved into the room temperature for continuous culture. These seedlings possessed the ability to earing after this kind of treatment, but earing development was rather late. Whereas the development of the earing was much earlier by treating them with 100 ppm trypsin just after moving into the room temperature condition. 2. Earing could not be induced by treatment with trypsin (100 ppm) in nonvernalized winter wheat. 3. Vernalization process was promoted in the initial period by trypsin under the low temperature, but it was inhibited in the middle and there was no remarkably effect on the developmental process in the later period. 4. There was no effect by the treatment of trypsin on the spring wheat under the conditions with or without vernalization. 5. The trypsinlike enzyme activity during the cold codication was increased in the initial period, then decreased remarkably later, but at the same time the soluble protein content increased rapidly. These results indicate that at the middle-later period of the vernalization the synthesis of some specific proteins is very important for the proceeding of varnalization. |