β-glucoronidase (GUS) activity driven by the <i>AtGH9C1</i> promoter in transgenic Arabidopsis.

<p>(<b>a</b>) Shahadara transgenic at 16–20 hours <u>p</u>ost <u>l</u>ight <u>i</u>ncubation (PLI), showing the seed coat ruptured (arrow). (<b>b</b>) 24–36 hours PLI showing seeds when the radicle has already emerged, and no signs of blue coloration. (<b>c</b>) 36–48 hours PLI showing strong blue coloration of GUS activity at emerging root hairs (arrow). (<b>d</b>) 72 hours PLI, showing the strong blue coloration at the collet zone (root-shoot junction) with a close up to the right. (<b>e)</b> 5 day old seedling showing strong GUS activity at the collet and at the differentiation zone of the main root. (<b>f)</b> close up of a main root tip showing GUS activity in trichoblast before the bulging and emergence of the root hair (black arrow). (<b>g</b>) emerging root hair proximal to the bottom cross wall of the trichoblast showing strong blue coloration<b>. (h)</b> Columbia transgenic seedlings growing in media supplemented with 1% sucrose with abundant and longer root hairs. (<b>i</b>) immature seed of a green silique positioned 1–1.5 cm down from the top flower bud, showing <i>AtGH9C1</i> expression in the micropylar endosperm (MCE), and toward the peripheral endosperm (PEN). (<b>j</b>) immature seed showing blue coloration in the embryo proper (EP) and the surrounding endosperm partially obscured by the encasing of the seed coat. Tissues were viewed in a light microscope at 40x. The bar lines in each photograph represent 200 µm.