Association of MatK with its target RNAs changes across tobacco development. A, Dot-blot analysis of the RNA from pellet (P) and supernatant (S) fractions of MatK:HA immunoprecipitations from the stroma of 7- and 25-d-old tobacco seedlings. C+, Plants tagged at the C terminus of MatK; N+, plants tagged at the N terminus of MatK. B, The ratios of pellet and supernatant signals were calculated and summarized for experiments with N+ and C+ plants. Means of these experiments are represented in a pie chart as ratios of the sum of all MatK targets. C, The ratio to ratio (25 d/7 d) is indicative of the developmental dependency of RNA-MatK interactions. This chart was derived from the experiment shown in A with immunoprecipitations from C- and N-terminally tagged plants considered as replicate experiments (error bars show sd). RNAs with values below 1 show a decrease in the association with MatK:HA in 25-d-old plants when compared with 7-d-old plants; values above 1 are the opposite.