Figure 3.

Sucrose-gradient sedimentation demonstrating that ZmWHY1 is associated with DNA- and RNA-containing particles in chloroplast stroma. Stromal extract was treated with DNAse or RNAse, or incubated under similar conditions without nuclease (Mock), and then sedimented through a sucrose gradient. An equal volume of each gradient fraction was analyzed by probing immunoblots with the antibodies indicated to the left. RPL2, a protein in the large ribosomal subunit, marks the position of ribosomes. Shown below is the blot of the mock-treated fractions stained with Ponceau S, with the RbcL band marked to illustrate the position of Rubisco. The Ponceau S stained blots of experiments involving the DNAse- and RNAse-treated extracts looked similar (data not shown).