Fig. 1.

The L.er accession encodes a suppressor that modifies vcs mutant RNA accumulation defects. (A) The Col-0 and L.er accessions appear very similar, but vcs alleles isolated in these two genetic backgrounds have different phenotypes. In Col-0, the vcs-7 mutant is chlorotic and fails to make leaves, whereas the vcs-1 mutant, isolated in L.er, is green and produces broad leaves. (B) Both suppressed and severe vcs phenotypes are among the F₂ after crosses of vcs-1 and vcs-7 mutants to Col-0 and L. er, respectively. (C) The relative expression of four RNAs in 3-d seedlings of both wild-type accessions and in vcs-1 (L.er) and vcs-7 (Col-0), determined by using quantitative real-time RT-PCR. These mRNAs accumulate to high levels in vcs-7, and in each case, the RNA accumulates to a lower level in the vcs-1 mutant. Error bars indicate SE (s.e.m.). (D) RNA ligation assay for the presence of a 5′ cap. Tobacco acid pyrophosphatase (TAP) addition indicated by a (+). Note that PCR products are produced in vcs-7 and vcs-1 mutants only after incubation with TAP, indicating that the abundant RNAs quantified in C retain their 5′ cap. (Scale bars: 1 mm.)