Hormone-induced increase in levels of functional mRNA and α-amylase mRNA in barley aleurones

Abstract
Incubation of barley cv. Himalaya aleurone cells with GA produces a progressive increase in the RNA content of the cells. The activity of poly(A)-containing RNA, measured in an in vitro wheat germ protein-synthesizing system, reaches a maximum .apprxeq. 12 h after hormone addition and declines thereafter. The structurally intact functional mRNA content in these cells, measured as poly(A)-RNA with 5'' "caps", also shows a maximum at 12 h and correlates with the translational capacity of poly(A)-RNA. Activation of mRNA by guanylylation or methylation after addition of GA is ruled out. Available evidence indicates that GA stimulates protein synthesis by increasing the synthesis of mRNA. Studies with cycloheximide suggest that the induction of synthesis of .alpha.-amylase mRNA by GA requires protein synthesis after hormone addition.