Figure 5.

Transient RNAi Suppression of TED6 and TED7 Genes in Arabidopsis Roots.

(A) Expression of At TED6 and At TED7 genes in transiently induced RNAi conditions. Inverted repeat sequences corresponding to At TED6, At TED7, and both were transiently expressed in transgenic Arabidopsis plants under control of the glucocorticoid-mediated induction system. Total RNAs were extracted from 1-week-old Arabidopsis seedlings that had been incubated on growth medium supplemented with 10 μM DEX for 5 h. All RT-PCR samples were prepared under the same conditions, except for PCR cycles: 25 cycles for At TED6 and actin2, and 30 cycles for At TED7 and ubiquitin.

(B) to (E) Phenotype of RNAi lines for At TED6 and At TED7 genes. Three-week-old transgenic Arabidopsis plants were incubated on growth medium supplemented with 10 μM DEX for 5 d to express inverted repeat sequences under control of the glucocorticoid-mediated induction system. Effects of RNAi were examined on vessel formation in later developed roots during induction. Bar in (B) for (B) to (G) = 50 μm.

(B) Wild type (Columbia-0). Metaxylem vessel elements with pitted SCW thickenings, distinguished from spiral SCW thickenings of protoxylem vessel elements aligned in the outsides.

(C) At TED7 RNAi line. Scalariform (ladder-shaped) metaxylem vessel elements.

(D) At TED6–TED7 chimera RNAi line. Gap in metaxylem vessel strand.

(E) YFP RNAi line. Large-pitted metaxylem vessel elements.