Analysis of rRNA processing and degradation.

<p>(A) Diagram illustrating the 5.8S rRNA processing intermediates and the rRNA maturation by-product generated from the 5ʹ ETS (P-Pʹ) compared with the 35S precursor [27]. Horizontal red arrows represent the positions of oligonucleotide probes used in this study. (B) The 5.8S rRNA 3ʹ extension is processed by AtRRP44A, AtRRP4 and AtRRP41, but not AtRRP44B/SOV. (C) The 5ʹ ETS is degraded by AtRRP44A, AtRRP4 and AtRRP41, but not AtRRP44B/SOV. RNA gel blots of 5.8S rRNA precursors (B) or the 5ʹ ETS (C). Total RNAs were isolated from 10 dpg rosette leaves of Col-0 (wild type: WT), <i>gusKD-2</i> (VC), <i>rrp44aKD-1</i>, <i>rrp44aKD-2</i>, <i>rrp44b-1</i>, <i>rrp44b-2</i> and <i>mtr4-1</i> plants or from <i>gusKD-2</i>, <i>rrp4KD-3</i>, <i>rrp41KD-1</i> and <i>rrp44aKD-1</i> plants (B and C). <i>mtr4-1</i> was used to determine the sequence of 5.8S processing intermediates [27]. Total RNAs were separated on 6% polyacrylamide gels. Methylene blue staining of 5S rRNA is shown as a loading control. Relative RNA levels estimated from band signals are indicated at the bottom of each lane as mean values ± SE with RNA levels in Col-0 plants set to 1.0.. Values for which P<0.05 (Tukey’s test) compared to corresponding wild type plants (<i>gusKD-2</i> or Col-0) were shown in red. Two (B and C: Left panels) or three (B and C: Right panels) biological replicates were performed for all RNA gel blots.