Figure 1.

Pre-mRNA accumulation induced by ethylene treatment is unaffected by PTGS and ASGS. RNase protection assays of total RNA (25 μg) extracted from leaves of untransformed tobacco (Wt), TAC, TAG, sibling silent (STSC), and high-expressing (HTSC) TSC plants before (−) and after (+) treatment with 20 ppm ethylene for 2 days. Intron/exon RNA probes for CHN50 (A and C) and Gla (B) mixed with a control U2 RNA probe were used. The positions of the RNA-species protected and probes before (−RNase) and after (+RNase) RNase digestion protected with tRNA are indicated.