Effects of exogenous auxin on the morphology and cell shape.

<p>WT (A-I) and _<i>pro</i><i>MpIAA</i>:<i>MpIAA</i>^<i>mDII</i><i>-GR</i> plants (J-R) were grown for 12 days in the absence of both NAA and DEX, then grown under mock condition (A, D, G, J, M, P), with 10 μM NAA (B, E, H, K, N, Q), or with 10 μM NAA and 10 μM DEX (C, F, I, L, O, R). At day 7 post treatment, photographs (A-C, J-L; bars: 10 mm) and scanning electron micrographs (D-I, M-R; bars: 500 μm) were taken.</p

DEX-inducible system for repressing auxin responses.

<p>(A, B) GUS staining (A) and quantitative fluorometric assays (B) of _<i>pro</i><i>GH3</i>:<i>GUS</i> and _<i>pro</i><i>MpIAA</i>:<i>MpIAA</i>^<i>mDII</i><i>-GR/</i>_<i>pro</i><i>GH3</i>:<i>GUS</i> transgenic plants. Each plant was treated with 10 μM NAA and/or 10 μM DEX for 12 h. Error bars: SE (n = 3).</p

Protein-protein interactions between MpIAA and MpARFs <i>in planta</i>.

<p>BiFC assays of MpIAA and MpARF using <i>N</i>. <i>benthamiana</i> leaves. Confocal images of YFP (yellow) and chloroplast auto-fluorescence (red) were merged with bright-field images. Vectors containing only nYFP or cYFP was used as negative controls. Bars: 50 μm.</p

Effects of mutations in domain II of MpIAA on auxin sensitivity.

<p>(A) Diagram of _<i>pro</i><i>MpEF1α</i>:<i>MpIAA</i> and _<i>pro</i><i>MpEF1α</i>:<i>MpIAA</i>^<i>mDII</i>. Two conserved proline residues in domain II were substituted with serine. (B) Resistance to auxin by domain II-modified MpIAA expression. Photographs of WT, _<i>pro</i><i>MpEF1α</i>:<i>MpIAA</i> and _<i>pro</i><i>MpEF1α</i>:<i>MpIAA</i>^<i>mDII</i> plants cultured with exogenous 3 μM NAA or under mock conditions for 2 weeks. Bars: 5 mm. The values indicate area ratios of 2-week-old thallus grown in the presence of NAA to that grown under mock conditions with SE (n = 12).</p

Auxin signaling factors in <i>M</i>. <i>polymorpha</i>.

<p>(A) Diagrams of domain structures of MpIAA and MpARFs. DBD: DNA-binding domain, Q-rich: glutamine-rich region, Roman numbers: domains I through IV. (B-D) Phylogenetic positions of MpIAA (B), MpARFs (C) and MpTIR1 (D) using the amino acid sequences from <i>M</i>. <i>polymorpha</i> (red), <i>P</i>. <i>patens</i> (green), <i>S</i>. <i>moellendorffii</i> (blue), and Arabidopsis (black). See <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1005084#pgen.1005084.s008" target="_blank">S2 Table</a> for sequence information. Numbers on the branches indicate bootstrap values. Bar in (A): 100 amino acid residues in length. Bars in (B-D): number of amino acid changes per branch length.</p

Expression pattern of <i>MpIAA</i> throughout the life cycle.

<p>GUS staining of _<i>pro</i><i>MpIAA</i>:<i>GUS</i> plants. (A) 3-week-old thallus. Arrow: gemma cup. (B) Longitudinal section of gemma cup. (C) Magnified view of the region shown by dotted line in (B). Arrows: developing gemmae. (D, E) Overview (D) and longitudinal section (E) of antheridiophore. The arrows represent antheridia. (F, G) Overview (F) and longitudinal section (G) of archegoniophore. Arrows: archegonia. (H-K) Sporophytes generated by crossing WT female and _<i>pro</i><i>MpIAA</i>:<i>GUS</i> male. (H) Overview of fertilized archegoniophore containing developing sporophytes (arrows). (I-K) Isolated developing sporophytes. The apices of the sporophytes are directed downward. Scale bars: 2 mm (A, H), 0.5 mm (B, I-K), 0.1 mm (C, E, G), 5 mm (D, F).</p

Tranactivation assay for MpARFs.

<p>(A) Diagrams of the constructs for dual luciferase assay. (B) Relative luciferase activity elicited by effector plasmid. The vector expressing only Gal4 DBD was used as a control. A virus-derived activation domain, VP16, was used for a positive control. See <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1005084#sec015" target="_blank">Material and Methods</a> for effector vectors. Error bars: SE (n = 3).</p