Figure 11.

a, Mother/daughter tuber system for studying the effects of tuber age on protein metabolism. Mother tubers (M) were stored at 4°C for 29 months, transferred to 23°C, and incubated in the dark for approximately 2 months to induce daughter (D) tubers. b, Tissue prints of PMC from longitudinal sections of 29-month-old mother and daughter tubers. Purple color indicates the presence of PMC. c, SDS-PAGE of proteins from mother and daughter tubers. Note the absence of PMC (double-headed arrow) and patatin (arrow) from the 29-month-old mother tuber, whereas daughter tubers contain high levels of both proteins. d, Gelatinolytic proteinase activities in extracts from mother tubers and their absence in extracts from daughter tubers.