Figure 3.

A Loss of ARF3 and ARF4 Negative Regulation in the wiry Mutants.

(A) to (F) In situ localization of ARF4, ARF3, and PHB transcripts in wild-type (WT) ([A] to [C]) and ago7-1 ([D] to [F]) vegetative apices. ARF4 mRNA is abaxial in leaf primordia and later it is expressed in pro-vascular and vascular strands (A). Its expression is stronger and broader in ago7-1 apices (D). ARF3 mRNA is detected in both sides of leaf primordia, with weaker expression in the SAM (B), and no change is detected in its expression pattern in ago7-1 apices (E). PHB mRNA is adaxial in leaf primordial and in the SAM center (C). It is strongly reduced in ago7-1 vegetative apices but remains adaxial in leaves. Insets in (A) and (D) show sections through P1 leaf primordia. Bars = 50 μm.

(G) and (H) An RNA gel blot of RNA extracted from wild-type and wiry shoots probed with ARF3 and ARF4 cDNAs. Bottom panel is the RNA loaded. Note the high levels of ARF4 mRNA in rdr6, ago7, and sgs3 shoots (G) and the high levels of ARF3 in the dcl4 shoots (H).

[See online article for color version of this figure.]