Increased postmitotic cell expansion in <i>atkin13a</i> mutants.

<p>(A) Developmental series of petal size for the indicated genotypes. Flower 1 represents the youngest open flower, while flower −1 is the oldest unopened flower bud. Values are normalized to the size of the wild-type petals from the oldest measured flowers. Values represent mean ± SEM (n<10 petals). (B) Gel-print images of wild-type petal cells from the indicated flower stages (after <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1004627#pgen.1004627-Smyth1" target="_blank">[71]</a>). (C) Petal-cell size from stage 10–11 buds is not different between wild type and <i>atkin13a-3</i> mutants. Values are mean ± SD of 50 petal cells each from more than 6 petals. (D) Etiolated hypocotyls are longer in <i>atkin13a-3</i> mutants than in wild type. Values are mean ±SD of 10 plants. 8-day old seedlings were measured. (E) Toluidine-blue stained cross section through a mature wild-type (left) and a mature mutant petal (right). Adaxial side is to the right in both images. (F) Cross-sectional cell area, cell height and cell width from petals of wild type and <i>atkin13a-3^EMS</i> mutants. Values are normalized to wild-type values and represent mean ± SD of 50 petal cells. (G) Thickness of petal-cell walls as measured from scanning-electron micrographs. Values are mean ± SEM of 100 petal cells from 10 petals, normalized to the wild-type value. (H) Scanning-electron micrographs of wild-type petals before (top left) and after (top right and bottom) freeze fracturing. Bottom image also indicates how measurements of cell-wall thickness were taken (pairs of white crosses). Length of scale bars is indicated. (I) Petal dry weight of the indicated genotypes. Values are mean + SD from 3 replicates of 50 petals each, normalized to the respective wild-type values. Differences between the three <i>atkin13a</i> mutant alleles are not statistically significant (n.s.). Asterisk indicates significant difference from wild-type at p<0.05 (with Bonferroni correction where appropriate).