Figure 3.

Protein blots derived from two developmental series. A, Time course emphasizing the period between early full expansion and middle senescence. Arabidopsis plants from a synchronous population grown under continuous light were harvested over a period of several days, and protein from the sixth true leaf was prepared. Protein blots were examined with the indicated antibodies. The photographs indicate the developmental stages of the leaves at each time. DAG, Days after germination. B, The broader time course shown in Figure 1A, left, examined with the indicated antibodies. Plants were grown under a 16-h photoperiod, and protein and RNA from the sixth true leaf was prepared. BCB is a known senescence-associated gene, ClpP is the proteolytic subunit of the Clp protease, and Toc75 is a component of the chloroplast import apparatus. Protein derived from equal volumes of leaf tissue was loaded. exp, Expansion; sen, Senescence.