Fig. 5.

RNA gel blot analyses of chloroplast small (s)RNA accumulation in Arabidopsis mda1. Five µg of low‐molecular‐weight leaf RNA (or 10 μg for psbJ and ndhA 3′) of the indicated genotypes were fractionated in denaturing polyacrylamide gels and transferred to nylon membrane. Blots were hybridized with oligonucleotide probes complementary to sequences of sRNAs accumulating in the chloroplast regions listed on the right. The accumulation of two sRNAs matching the 5′‐end of psaC or rbcL messenger RNAs whose RNA abundance are unaffected in mda1 were monitored as internal controls. A portion of one of the gels stained by ethidium bromide (EtBr) is shown below to illustrate equal loading.