The Influence of Light on Synthesis of Protein and of Chlorogenic Acid in Potato Tuber Tissue

Disks of tuber tissue maintained in a moistened environment increase substantially in both protein content (18, 19, 21) and phenolic content (28). The 2 processes have not previously been considered as related. However, the stimulation by light of phenolic synthesis in tuber slices (11, 16) has been found to depend largely on the synthesis of proteins. Data which relate the production of phenolic substances to a stimulation of protein synthesis by light are presented in this paper. It is proposed that much of the phenolic synthesis in tuber slices exposed to light results from the initiation of chloroplast development in the tissue. The changes in respiration which develop in aerated tuber disks (4,10, 15, 24) were linked to protein synthesis by Steward and Preston (18,19) as early as 1940. Subsequently, chloramphenicol, a substance used to inhibit protein synthesis, was shown to inhibit the development of an altered respiration in aerated disks (2), an observation which suggested a direct causative relationship between protein synthesis and the alteration of respiratory activity in the disks. An analogous relationship between the synthesis of proteins and of phenolic substances is described in the present study.